Lithology, petrography, and geochemistry of three cores from the Goldfield mining district, Nevada

Ashley, R. P., Evarts, R.C. · 1990 · Report

Lithology, petrography, and geochemistry of three cores from the Goldfield mining district, Nevada by Ashley, R. P., Evarts, R.C. (1990). Full text and…

Public-domain full text preserved in the Mountain Man Mining Library. Original source: pubs.usgs.gov.

UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY LITHOLOGY, PETROGRAPHY, AND GEOCHEMISTRY OF THREE CORES FROM THE GOLDFIELD MINING DISTRICT, NEVADA By Roger P. Ashley and Russell C. Evarts U.S. Geological Survey Open-File Report 90-62 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

TABLE OF CONTENTS Introduction ! Purpose of individual drill holes, and site selection 1 Methods of investigation 4 Site locations 4 Lithologic descriptions 5 Sampling methods 5 Summary lithologic logs 6 Detailed lithologic logs 12 Drill hole USGS 1 12 Drill hole USGS 2 21 Drill hole USGS 3 28 raphicdata 33 Methods of investigation 33 Results 33 emicaldata 41 Analytical methods 41 Results 41 Drill hole USGS 1 41 Drill hole USGS 2 100 Drill hole USGS 3 130 References 142

LIST OF TABLES Table 1. Summary information for USGS drill holes at Goldfield, Nevada 3 Table 2. Summary log for drill hole USGS 1 6 Table 3. Summary log for drill hole USGS 2 8 Table 4. Summary log for drill hole USGS 3 10 Table 5. Petrographic data for thin sections taken from drill hole USGS 1 34 Table 6. Petrographic data for thin sections taken from drill hole USGS 2 38 Table 7. Petrographic data for thin sections taken from drill hole USGS 3 40 Table 8. Chemical data for drill hole USGS 1 63 Table 9. Chemical data for drill hole USGS 1, detailed sampling 92 Table 10. Chemical data for drill hole USGS 2 115 Table 11. Chemical data for drill hole USGS 3 138

LIST OF ILLUSTRATIONS Figure 1. Geologic map of the Goldfield mining district, showing locations of drill holes 2 Figure 2A. Geochemical logs for gold and silver, drill hole USGS 1 43 Figure 2B. Geochemical logs for arsenic and mercury, drill hole USGS 1 45 Figure 2C. Geochemical logs for copper and zinc, drill hole USGS 1 47 Figure 2D. Geochemical logs for lead and bismuth, drill hole USGS 1 49 Figure 2E. Geochemical log for manganese, drill hole USGS 1 51 Figure 2F. Geochemical logs for chromium and vanadium, drill hole USGS 1 53 Figure 2G. Geochemical log for barium, drill hole USGS 1 55 Figure 2H. Geochemical log for iron, drill hole USGS 1 57 Figure 21. Geochemical log for magnesium, drill hole USGS 1 59 Figure 2J. Geochemical log for calcium, drill hole USGS 1 61 Figure 3A. Geochemical logs for gold and tellurium, drill hole USGS 1 detailed sampling 75 Figure 3B. Geochemical logs for antimony and arsenic, drill hole USGS 1 detailed sampling 76 Figure 3C. Geochemical log for mercury, drill hole USGS 1 detailed sampling 77 Figure 3D. Geochemical logs for copper and zinc, drill hole USGS 1 detailed sampling 78 Figure 3E. Geochemical logs for lead and silver, drill hole USGS 1 detailed sampling 79 Figure 3F. Geochemical log for bismuth, drill hole USGS 1 detailed sampling 80 Figure 3G. Geochemical log for molybdenum, drill hole USGS 1 detailed sampling 81 Figure 3H. Geochemical log for tin, drill hole USGS 1 detailed sampling 82 Figure 31. Geochemical logs for boron and beryllium, drill hole USGS 1 detailed sampling 83 Figure 3J. Geochemical log for manganese, drill hole USGS 1 detailed sampling 84 Figure 3K. Geochemical logs for chromium and vanadium, drill hole USGS 1 detailed sampling 85 Figure 3L. Geochemical log for barium, drill hole USGS 1 detailed sampling 86 Figure 3M. Geochemical log for iron, drill hole USGS 1 detailed sampling 87 Figure 3N. Geochemical log for magnesium, drill hole USGS 1 detailed sampling 88 Figure 3O. Geochemical log for calcium, drill hole USGS 1 detailed sampling 89 Figure 3P. Geochemical log for titanium, drill hole USGS 1 detailed sampling 90 Figure 3Q. Geochemical log for zirconium, drill hole USGS 1 detailed sampling 91 Figure 4A. Geochemical logs for gold and arsenic, drill hole USGS 2 101 in

Figure 4B. Geochemical log for mercury, drill hole USGS 2 103 Figure 4C. Geochemical logs for copper and molybdenum, drill hole USGS 2 105 Figure 4D. Geochemical log for lead, drill hole USGS 2 107 Figure 4E. Geochemical logs for barium and strontium, drill hole USGS 2 109 Figure 4F. Geochemical logs for magnesium and iron, drill hole USGS 2 Ill Figure 4G. Geochemical logs for manganese and calcium, drill hole USGS 2 113 Figure 5A. Geochemical logs for gold and arsenic, drill hole USGS 3 131 Figure 5B. Geochemical log for mercury, drill hole USGS 3 132 Figure 5C. Geochemical logs for copper and molybdenum, drill hole USGS 3 133 Figure 5D. Geochemical log for lead, drill hole USGS 3 134 Figure 5E. Geochemical logs for barium and strontium, drill hole USGS 3 135 Figure 5F. Geochemical logs for magnesium and iron, drill hole USGS 3 136 Figure 5G. Geochemical logs for manganese and calcium, drill hole USGS 3 137

INTRODUCTION BACKGROUND Between July, 1968 and February, 1969, the U.S. Geological Survey drilled three exploration bore holes in the Goldfield mining district, Esmeralda County, Nevada. This activity was one component of a comprehensive study of the geology and geochemistry of the Goldfield district. The main objective of the drilling was to provide information on the geometry of fault systems in the Early Miocene volcanic rocks that host the gold deposits. Other objectives were to test the hypothesis that caldera collapse and resurgence produced several major structural features in the district, and to look for changes in the character of hydrothermal alteration with depth. The purpose of this report is to present all the data we have obtained from cores from the Goldfield drill holes. These data include detailed descriptive logs based on visual examination of the cores, summary logs derived from the detailed logs, mineral assemblages based on petrographic observations for samples selected from the cores, and chemical analyses of core splits. The drill hole locations are shown on a preliminary geologic map of the Goldfield district (Ashley, 1975). Each drill hole is included in a cross section that shows the stratigraphic units recognized in that hole and their relationships to other units in the vicinity. In this report all descriptions are in terms of lithology; stratigraphic assignments are not treated here. PURPOSE OF INDIVIDUAL DRILL HOLES, AND SITE SELECTION Locations of the three drill holes are shown on figure 1, and basic information about each hole is summarized in table 1. Except for relatively thin zones of colluvium at the surface, cores were obtained for the full lengths of all three holes. The main productive vein system of the Goldfield district, located immediately northeast of the town of Goldfield, trends north and dips east. The dip of this vein system is about 45° near the surface, but decreases with increasing depth. In the Merger mine (fig. 1) at a depth of about 400 m (1300 ft), it lies on the contact between Tertiary volcanic rocks and pre-Tertiary metasedimentary rocks, and dips to the east at 10-15° (Ashley, 1974: Ransome, 1909). Goldfield USGS 1 was drilled to determine whether the main productive vein system extends eastward from the Merger mine at a low angle, either along or beneath the basement surface. A related question is whether the pre-Tertiary basement surface was a locus for hydrothermal alteration, indicating that it was a channel-way for solutions. Also of interest is whether mineralized east-dipping fractures exist in the volcanic section above a possible extension of the main vein system. Thus important objectives for this hole included determining depth to pre-Tertiary basement, and detecting altered and mineralized fracture zones both above and below this contact. To achieve the goals for this hole, we were prepared to drill as deep as 600 m (2000 ft).

37°45' 37° 42.5' EXPLANATION Quaternary and Tertiary sedimentary and volcanic rocks and alluvium Lower Miocene andesite and rhyodacite, locally intrusive Oligocene silicic flows and tuffs Pre-Tertiary quartz monzonite, shale, and limestone Drill hole location Area of major gold production 1 MILES KILOMETERS Figure 1. Geologic map of the Goldfield mining district, showing locations of USGS drill hoRs 117° 15'

Table 1. Summary information for USGS drill holes at Goldfield, Nevada. Drill hole USGS 1 Drill hole USGS 2 Drill hole USGS 3 Location SE 1/4, SE 1/4, Sec. 36, T. 2 S, R. 42 E SW 1/4, NE 1/4, Sec. 19, T. 2 S, R. 43 E SW 1/4, SE 1/4, Sec. 25, T. 2 S, R. 42 E Bearing and inclination Vertical at collar N 10° E, -60° at collar Vertical at collar Vertical at 700 ft (213 m) N 9 1/2° E, -60° at 590 ft (180 m) S 62° W, -87° at 1500 ft (457 m) N 9° E, -61° at 1100 ft (335 m) Starting date; completion date July 8,1968; Oct. 9, 1968 Oct. 21, 1968; Jan. 6, 1969 Jan. 14, 1969; Feb. 7, 1969 Core size, interval NC, 10-671 ft (3.0-204.5 m) NC, 14-969 ft (4.3-295.4 m) NC, 10-457 ft (3.0-139.3 m) NX, 671-1,505 ft (204.5-458.7 m) NX, 969-1,439 ft (295.4-438.6 m)

The site for USGS 1 was selected based on information from the Merger and other nearby mines (Ransome, 1909: Goldfield Consolidated Mines Corporation, unpub. data), and on surface geology (Ashley, 1975), which suggested that there might be a local depression in the pre-Tertiary basement surface. The exact site was adjusted to allow use of an existing secondary road. The McMahon Ridge area (fig. 1) was productive, but far less so than the main area near Goldfield. Ransome (1909) gives an account of the character and orientation of veins in this area, which is summarized by Ashley (1974). The altered and mineralized faults and fracture zones trend east-west to northeast, and most show vertical or northerly dips, but these veins were developed to depths of only about 120 m (400 ft). Goldfield USGS 2 was designed to test whether the fracture system of McMahon Ridge dips to the south at depth, as might be expected if it formed above a buried caldera wall, and to see whether alteration and mineralization increased or decreased in intensity with depth. Depth to pre- Tertiary basement, and alteration at the Tertiary-basement contact were targets for this drill hole as well as USGS 1. Funds available for the project constrained this drill hole to a maximum depth of 460 m (1500 ft), assuming that USGS 1 would go to a depth of 600m. The site for USGS 2 was selected based on Ransome's subsurface information and surface geology (Ashley, 1975). A northerly-directed inclined borehole (-60°) was located 200 m south of the outcrop line of the McMahon Ridge vein system. The drill hole was oriented to detect structures dipping to the south at moderate angles, and to achieve at the same time considerable depth with the hope of reaching basement within the 1500-foot constraint. The third drill hole, about three km northeast of the town of Goldfield, is located about 1 km east of the inferred western margin of the caldera, in post- collapse volcanic flows of early Miocene age. Immediately east of this location, caldera-related silicic tuffs and flows and pre-Tertiary rocks are exposed in what may be a resurgent core of the caldera. The structure in this area, however, is complicated by numerous north-northeast-trending, east-dipping normal faults. The blocks bounded by the faults are rotated to moderate westerly dips. This hole was drilled mainly to test whether an angular unconformity separates caldera- related and post-caldera units; such an unconformity could be the result of resurgence at the end of the caldera-formation cycle. The site for USGS 3 was selected based on surface geology (Ashley, 1975), and adjusted to take advantage of existing secondary roads. Field mapping showed that the Oligocene units in the vicinity include bedded tuffs and welded ash flow tuffs that would make suitable structural markers. METHODS OF INVESTIGATION Site locations Detailed geologic field mapping of the Goldfield mining district preceded this drilling program. Because an adequate large-scale base map was not available, we recorded geologic field data on aerial photographs, and located the drill hole sites initially on the same aerial photographs. We then located the sites in the field by inspection of the aerial photographs, and attempted to locate them with respect to

boundaries of patented claims by bearing-and-chain measurements from various monuments. Site locations were not surveyed. Lithologic descriptions We made preliminary descriptions of the core in the field at the time of drilling, using field methods. At the end of the project, the core was shipped to Menlo Park, California, where we examined all of it in more detail, making occasional use of a binocular microscope and X-ray diffractometer. The descriptions were later modified somewhat based on the results of detailed petrographic studies. The summary descriptions are derived entirely from the detailed logs. Sampling methods In the course of describing the core, we removed samples for petrographic study and chemical analysis. For petrography, we selected samples representative of the range of materials in a described interval. Because some intervals are more heterogeneous than others, some include only one sample, whereas others include several. In some cases, pairs of samples bracket notable changes in the core. The samples for petrography consist of splits of core 10-15 cm long. We examined conventional thin sections and X-ray diffractograms for all these samples. We sampled the entire length of core from each drill hole for chemical analysis. Individual samples generally represent intervals between 2 and 3 meters long. The samples are composites consisting of splits of core 15-20 cm long taken at intervals of 60-80 cm. Thus a typical sample is a composite of four split pieces of core. Drill hole USGS 1 was sampled in detail between depths of 921 and 1083 feet; here samples are composites consisting of splits about 10 cm long taken at intervals of 25-30 cm. Analytical methods are given in the analytical data section. Although the purpose of petrographic and chemical analyses was to characterize the cores lithologically and geochemically, results from these two types of analyses and the accompanying descriptions do not always correlate perfectly. The main sources of differences are that petrographic sampling sometimes does not cover all the variations in a described interval, and samples for chemical analysis generally, but not always, cover smaller intervals than petrographic samples. Following detailed description and sampling, we condensed the core to about 10 percent of its original length by removing selected pieces of core about 8-10 cm long. The condensed core is stored in a core library maintained by the Nevada Bureau of Mines and Geology in Reno, Nevada.

Feet SUMMARY LITHOLOGIC LOGS Table 2. Summary log for drill hole USGS 1. Meters Summary description 118-194.5 194.5-238 486-494.2 494.2-617 617-626.7 626.7-633 736-748.4 748.4-790 Colluvium. Soft white argillized rhyodacite. 14.6-36.0 Soft medium-gray to white argillized rhyodacite. Unoxidized with as much as 5 percent pyrite. 36.0-59.3 Hard dark-bluish-gray propylitized rhyodacite. Locally argillized. 59.3-72.5 Soft, locally moderately hard, pale-gray argillized andesite. 72.5-94.2 Hard medium-to dark-gray propylitized andesite, locally soft, argillized; poor relict texture. Abundant calcite veinlets. 94.2-130.8 Hard pale-green or pale-purple, propylitized latite, and soft pale-gray argillized latite. One percent pyrite throughout most of interval. 130.8-148.1 Hard deuterically altered latite. Very fine grained hematite gives bluish to purplish color. Good relict texture. Pyrite absent. 148.1-150.6 Moderately hard pale-green-purple latite, strongly fractured with soft white argillized material along fractures. Good relict texture. 150.6-188.1 Hard pale-green-purple to dark-purple propylitized latite, locally strongly fractured, argillized. 188.1-191.0 Soft white argillized latite. 191.0-192.9 Hard medium- to dark-gray siltstone, and fine-grained sandstone (Palmetto Formation). Upper part argillized; 5 percent pyrite. 192.9-222.8 Dense brittle dark-gray calcareous siltstone. Locally fractured and altered below 661.5 ft (201.6 m). 222.8-224.5 Soft black carbonaceous siltstone, intensely fractured and crushed. 224.5-228.1 Fault zone. 228.1-240.8 Soft black carbonaceous siltstone, intensely fractured and crushed. 240.8-247.8 Fault zone; poor core recovery.

247.8-275.8 Hard pale-gray crystalline limestone, locally brecciated. 275.8-282.2 Soft dark-gray to black locally calcareous carbonaceous siltstone, mostly brecciated. 926-942.5 282.2-287.3 White medium-grained quartz monzonite, soft to moderately hard, more or less argillized. 942.5-963.7 287.3-293.7 Hard pale- to medium-green feldspar-rich pegmatite, with mica-rich zone at 943.5948 ft (287.6-289.0 m) and molybdenite visible 962.5-963.7 ft (293.4-293.7 m). 963.7-975 293.7-297.2 Soft to moderately hard white argillized quartz monzonite. 975-1,044.5 297.2-318.4 Hard mottled pale-pink and pale-gray marble, locally siliceous. 1,044.5-1,048.5 318.4-319.6 Fractured to brecciated gray marble; montmorillonite with pyrite in matrix. 1,048.5-1,069 319.6-325.8 Dense medium-olive-green epidote skarn. Minor molybdenite and chalcopyrite visible locally. 1,069-1,085.5 325.8-330.9 Hard to moderately soft pale-gray to white medium-grained quartz monzonite, more or less argillized. 1,085.5-1,121 330.9-341.7 Soft white argillized quartz monzonite. 1,121-1,142 341.7-348.1 Hard to soft pale-gray to white medium- grained quartz monzonite, more or less argillized. 1,142-1,185 348.1-361.2 Hard slightly propylitized quartz monzonite with pink potassium-feldspar and gray to green plagioclase. 1,185-1,223 361.2-372.8 Hard white to pale-gray weakly propylitized quartz monzonite. 1,223-1,341.5 372.8-408.9 Hard slightly propylitized quartz monzonite. 1,341.5-1,362.4 408.9-415.3 Hard pale-green-purple propylitized andesite, locally soft, argillized. Probably a dike. 1,362.4-1,448 415.3-441.4 Hard slightly propylitized quartz monzonite. 1,448-1,505 441.4-458.7 Hard pink (due to unaltered potassium feldspar) to soft white more or less strongly argillized quartz monzonite.

Feet Table 3. Summary log for drill hole USGS 2. Meters Summary description 36.3-48.8 48.8-90.2 90.2-151.5 497-572.5 572.5-613 796-971.5 151.5-174.5 174.5-186.8 186.8-205.7 205.7-242.6 242.6-296.1 Colluvium. Dark-green to purplish-green propylitized porphyritic andesite. Carbonate and zeolite veins and amygdules common. Propylitized to weakly argillized andesite flow breccia (rock type same as above). Veins and amygdules persist. Propylitized porphyritic andesite with much flow breccia. Unoxidized, with minor pyrite from 166 ft (50.6 m) down, but oxidized areas persist locally to 290 ft (88.4 m). Strongly crushed 290 to 296 ft (88.4-90.2 m). Veins and amygdules throughout. Propylitized porphyritic andesite, unoxidized. Carbonate and zeolite veins and amydgules persist. Purplish zones several feet thick, with relatively abundant hematite in groundmass, scattered through interval 402 to 479 ft (122.5-146.0 m). Relatively abundant epidote, also many broken zones 479 to 497 ft (146.0-151.5m). Gray, propylitized to argillized, porphyritic andesite. Gray, propylitized to weakly argillized, porphyritic andesite with vague relict texture, locally oxidized. Pale-gray more or less intensely argillized andesite. Clay seams common, zeolites and carbonate rare. Strongly argillized porphyritic andesite. Many fractured and crushed zones throughout. Breccia zones at 732 ft (223.1 m) and 738 ft (224.9 m). Argillized andesite; locally propylitized, with poor relict texture. Fractured and crushed zones moderately abundant.

971.5-1,006.5 296.1-306.8 Light-gray argillized, andesitic lithic tuff; strongly fractured and crushed. 1,006.5-1,016 306.8-309.7 Light-gray propylitized, porphyritic andesite. 1,016-1,055 309.7-321.6 Light-gray argillized, andesitic tufK?). 1,055-1,134.5 321.6-345.8 Argillized porphyritic andesite. Montmorillonite seams common. 1,134.5-1,158 345.8-352.9 Aphanitic to porphyritic andesite. Alternating zones of propylitic and argillic alteration. Intensely crushed and fractured. 1,158-1,164 352.9-354.8 Probable fault zone; no core recovered. 1,164-1,265 354.8-385.6 Porphyritic andesite, gray to purple propylitic in upper part grading down into light-gray argillized rock. Generally good relict texture. 1,265-1,278.5 385.6-389.7 Dark-gray to black argillized and pyritized montmorillonitic rhyodacite tuff. 1,278.5-1,337.5 389.7-407.7 Very poorly sorted lithic-crystal rhyodacite lapilli tuff; argillized. 1,337.5-1,395 407.7-425.2 Dark-gray to black argillized montmorillonitic rhyodacite tuff, lapilli tuff, sandstone, and conglomerate. 1,395-1,400.5 425.2-426.9 Amygdular propylitized porphyritic andesite containing inclusions of sedimentary rocks; probably intrusive. 1,400.5-1,437 426.9-438.0 Light- to dark-gray poorly sorted, argillized rhyodacite tuff and conglomerate. 1,437-1,439 438.0-438.6 Brecciated propylitized porphyritic andesite; possibly a dike or sill.

Feet Table 4. Summary log for drill hole USGS 3. Meters Summary description 94.5-120.5 120.5-156.5 156.5-172 214-220.5 220.5-243.8 243.8-249.7 249.7-289 383-394.8 394.8-396 399-404.3 404.3-421.6 421.6-423 Colluvium. Hard dark-bluish-gray propylitized rhyodacite. 28.8-36.7 Hard more or less intensely fractured to soft crushed propylitized and argillized rhyodacite. Olive brown to yellow brown due to limonite stain. 36.7-47.7 Hard locally fractured medium-bluish- to greenish-gray propylitized rhyodacite. Disseminated hematite gives bluish color. 47.7-52.4 Hard medium-gray-green propylitized rhyodacite. 52.4-65.2 Moderately hard to moderately soft, propylitized and argillized rhyodacite with many soft argillized zones. 65.2-67.2 Hard pale-greenish-gray propylitized and arg&lized rhyodacite. Unoxidized. 67.2-74.3 Soft crushed to moderately hard argillized and propylitized dacite. 74.3-76.1 Moderately hard pale-gray propylitized and argillized rhyodacite. 76.1-88.1 Hard fractured to soft crushed propylitized and argillized rhyodacite. 88.1-99.4 Hard pale-purple to pale-blue (nearly white) propylitized to argillized rhyodacite. 99.4-107.0 Soft white to light-gray argillized rhyodacite. 107.0-111.3 Moderately hard white argillized rhyodacite flow breccia. 111.3-116.1 Soft locally crushed to hard intensely fractured, white to pale-green, argillized and propylitized dacite. 116.1-116.7 Fault zone(?). 116.7-120.3 Hard locally strongly fractured propylitized and argillized rhyodacite flow breccia. 120.3-120.7 Soft dark-gray argillized volcanic conglomerate. Bedding dips 40°-45°. 120.7-121.6 Soft argillized latite tuff. 121.6-123.2 Soft argillized volcanic conglomerate. 123.2-128.5 Soft argillized latite tuff. 128.5-128.9 Soft argillized volcanic conglomerate.

128.9-129.2 Hard broken medium-green latite tuff. 424-428.4 129.2-130.6 Soft argillized fault breccia. 428.4-437 130.6-133.2 Very soft argillized latite tuff. Brecciated 430.5 to 437 ft (131.2-133.2 m). 133.2-136.9 Hard strongly fractured pale-green propylitized and argillized rhyodacite. 136.9-137.8 Very soft argillized latite tuffl?). 452-452.5 137.8-137.9 Fault zone. 452.5-457 137.9-139.3 Hard intensely fractured propylitized and argillized latite.

DETAILED LITHOLOGIC LOGS DRILL HOLE USGS 1 Detailed description, intervals in feet (meters): 0-10 (0-3.0) Colluvium. 10-48 (3.0-14.6) Soft white montmorillonite-bearing argillized rhyodacite with good relict porphyritic texture; oxidized, with moderately heavy red and yellow-brown limonite stain locally. Thin white montmorillonite seams, dip 30°-70°, about one per 5 ft (1.5 m) of core. Few randomly oriented gypsum veinlets as much as 1 cm wide in the intervals 29 to 34 ft (8.8-10.4 m) and 36 to 38 ft (11.0-11.6 m). 48-118 (14.6-36.0) Soft medium-gray to white montmorillonite-bearing argillized rhyodacite with moderately good relict porphyritic texture. Unoxidized except for yellow to red limonite-stained interval at 68 to 72 ft (20.7-21.9 m) and partial alteration of pyrite to limonite at 110 to 118 ft (33.5-36.0 m). Where color is gray, contains about 5 percent pyrite, both disseminated and replacing mafics; where white, pyrite is scarce, disseminated. Montmorillonite seams dipping 10°-65° appear at 83 to 88 ft (25.3-26.8 m) and 93 to 110 ft (28.3-33.5 m), one to ten per foot of core. Below 101 ft (30.8 m), rock becomes harder, with flow breccia zone 101.3 to 107 ft (30.9-32.6 m). 118-194.5 (36.0-59.3) Hard dark-bluish-gray propylitized rhyodacite. About half the rock is weakly to moderately strongly argillized, moderately hard to soft, in the intervals 118 to 135.5 ft (36.0-41.3 m), 144.2 to 153 ft (44.0-46.6 m), 186.5 to 194.5 ft (56.8-59.3 m). Propylitized and argillized rock alternate at spacings of 3 in. to 1 ft (7.6-30.5 cm) in these intervals. Argillized areas have montmorillonite seams in diverse orientations. Intervals free of argillization 135.5 to 144.2 ft (41.3-44.0 m) and 153.0 to 186.5 ft (46.6-56.8 m) have thin calcite veinlets in diverse orientations, 1 to 3 per foot. Pyrite very scarce in propylitized rock, reaches 5 percent in argillized rock. 194.5-238 (59.3-72.5) Pale-gray argillized andesite, soft to locally moderately hard, generally poor relict porphyritic texture (phenocrysts less than 0.5 mm diameter). Softer areas have moderately abundant montmorillonite seams; harder areas at 196.5 to 199 ft (59.9-60.7 m), 204 to 206 ft (62.2-62.8 m), 206.5 to 210 ft (62.9-64.0 m), 210.7 to 211.5 ft (64.2-64.5 m), and 225.5 to 228 ft (68.7-69.5 m) have no montmorillonite seams but contain several calcite veins to 1 mm wide per foot, in diverse orientations. Pyrite locally partly altered to limonite. Few discontinuous pyrite veinlets in diverse orientations, 204 to 211.5 ft (62.2-64.5 m), locally partly altered to limonite.

238-309 (72.5-94.2) Hard medium- to dark-gray propylitized andesite with local soft argillized zones. Poor relict texture. Calcite veins to 3 mm wide in diverse orientations, several per foot throughout. Two to 5 percent very fine grained disseminated pyrite to 263 ft (80.2 m); below this, propylitized core is predominantly dark purplish gray with less than 2 percent pyrite and hematite seams; individual seams or zones with several seams occur every 5 ft (1.5 m). Patchy laumontite coatings on fractures, 248 to 262 ft (75.6-79.9 m). Pale to medium-gray soft argillized zones occur at 258.5 to 258.7 ft (78.8-78.9 m), 226 to 269 ft (68.9-82.0 m), 281 to 282 ft (85.6-86.0 m), 290 to 292.5 ft (88.4-89.2 m), 301.5 to 303 ft (91.9-92.4 m), 305.0 to 309 ft (93.0-94.2 m). 309-317 (94.2-96.6) Moderately hard medium-green propylitized latite; locally argillized. Good relict texture. Argillized at 309 to 311 ft (94.2-94.8 m), 313 to 314.5 ft (95.4-95.9 m), 315.7 to 316 ft (96.2-96.3 m); pale green with some fractures coated with montmorillonite. Propylitized intervals intensely fractured with powdery calcite coatings on fractures. Pyrite absent; contains minor hematite (hornblende altered to hematite; biotite altered to white mica with minor hematite). 317-429 (96.6-130.8) Hard pale-gray to very pale purple (nearly white) propylitized latite with good relict texture. Vague to moderately strong flow banding throughout, dips 25°- 60°, generally 40°-55°, shown by slight color variations and locally by entrained elongate dark purple aphanitic inclusions. Contains some calcite and 1 percent pyrite (to 0.25 mm) throughout. Locally moderately soft to soft pale gray to white argillized zones, with poor relict texture, no calcite, 2 to 5 percent pyrite (to 0.1 mm), and some pale-gray montmorillonite seams. Argillized at 317 to 326 ft (96.6-99.4 m), 341.6 to 355.1 ft (104.1-108.2 m), 355.6 to 357.3 ft (108.4-108.9 m), 357.7 to 358.2 ft (109.0-109.2 m), 366 to 367 ft (111.6-111.9 m), 368.4 to 370.2 ft (112.3-112.8 m), 381 to 381.5 ft (116.1-116.3 m), 395.5 to 398 ft (120.5-121.3 m), and 399 to 401.5 ft (121.6-122.4 m). Contacts between argillized and propylitic rocks where visible dip 30°-50°. Propylitized intervals have irregular vugs as much as 7 cm across partly to completely filled with calcite (larger vugs usually elongate). Frequency of occurrence of calcite in any one of these forms is one every 1 to 2 ft (1.3 per m). Starting at 386 ft (117.7 m), rock becomes progressively darker purple in color with depth, and at 417.3 ft (127.2 m) contains a few hematite veinlets to 4 mm wide. 429-486 (130.8-148.1) Hard to very hard medium-purple to pale-purplish-blue latite, deuterically altered (oxidized). Good relict texture. Mafics altered to magnetite; pyrite absent. Color due to fine-grained hematite in groundmass. Flow banding visible through most of interval, shown by minor color variations, dips 30°-50°, mostly 45°-50°. At 453 to 454.5 ft (138.1-138.5 m), irregular purple and pale-green flow bands are contorted and jumbled. Flow banding also shown locally by dark- purple, elongate, aphanitic bands and (or) ragged to subrounded inclusions to 1 cm wide. Fractures with diverse orientations occur with a frequency of one every

2 to 3 ft to 2 per foot (1-6 per m); most have coatings of calcite with some clay, except from 435 to 447 ft (132.6-136.2 m), where the calcite is accompanied by hematite instead. Locally there are scattered amygdules to 1 cm in diameter filled with calcite, at some places elongate parallel to flow banding. Zone of weak argillization at 469.2 to 469.6 ft (143.0-143.1 m) dips 45°. 486-494.2 (148.1-150.6) Strongly fractured pale-green-purple weakly argillized latite, with soft white clay (mainly montmorillonite) along fractures. Good relict texture. Scarce very fine grained pyrite. Clay along fractures contains about 3 percent very fine grained pyrite. Fractures have diverse orientations, spacing usually less than 5 cm, maximum spacing about 15 cm. 494.2-617 (150.6-188.1) Hard pale-green-purple to dark-purple propylitized latite, locally strongly fractured and weakly to moderately strongly argillized. Relict texture good where propylitized, poor where argillized. Flow banding, shown by mineral alinement and darker purple bands to 2 cm wide, dips 20°-65° generally 40°-60°. Locally poorly developed flow breccia zones parallel flow banding. Few scattered angular aphanitic dark-purple inclusions. At 494.2 ft (150.6 m) color is pale green purple; becomes more purple with depth, pale- to medium-purple below 503 ft (153.3 m). Pyrite absent to 552.5 ft (168.4 m). Becomes pale green again, locally with purplish tinge, 552.5 to 600 ft (168.4-182.9 m) and 615.5 to 617 ft (187.6-188.1 m). Purple color due to hematite after mafics and disseminated in groundmass. Fractures throughout are coated with calcite and clay; calcite is dominant in propylitized rock and montmorillonite is dominant in argillized rock. Argillized at 494.2 to 502 ft (150.6-153.0 m), 506 to 507 ft (154.2-154.5 m), 508 to 510.5 ft (154.8-155.6 m; sharp upper contact dips 50°), 535.5 to 535.6 ft (163.2-163.3 m), 540 to 541 ft (164.6-164.9 m; upper and lower contacts dip 60° and 65°, respectively), 550 to 551.5 ft (167.6-168.1 m), 556 to 557 ft (169.5-169.8 m), 561 to 562 ft (171.0-171.3 m), 562.5 to 563 ft (171.5-171.6 m), 584.5-587.5 ft (178.2-179.1 m), 588.2 to 599.5 ft (179.3-182.7 m), and 615 to 615.5 ft (187.5- 187.6 m; may be a tectonic breccia; upper contact sharp, dips 30°, lower contact irregular). Below 552.5 ft (168.4 m), propylitized rock has 1 to 3 percent, locally 5 percent pyrite and argillized rock has 2 to 5 percent pyrite, replacing mafics and disseminated as 0.25 mm grains. 617-626.7 (188.1-191.0) Soft bluish-white argillized latite. Relict texture vague. Montmorillonite seams with slickenside surfaces throughout. One to 2 percent pyrite throughout, grains less than 0.1 mm diameter. May also contain minor very fine grained disseminated hematite. Rock at 617 to 621.7 ft (188.1-189.5 m) is probably flow breccia, with a 5-cm limestone fragment at 620.4 ft (189.1 m). Rock at 621.7 to 626.7 ft (189.5-191.0 m) is also a breccia but fragments not rotated, flow banding dips 20°-30°. Basal contact sharp, depositional, dips 35°.

626.7-633 (191.0-192.9) Hard medium- to dark-gray siltstone and fine-grained sandstone (Palmetto Formation, Ordovician age). Argillized at 626.7 to 629.2 ft (191.0-191.8 m), with fine to very fine montmorillonite seams. Five percent patchy fine grained pyrite. Bedding dips 35°. At 629.2 to 633 ft (191.8-192.9 m) rock is unaltered dark-gray massive siltstone with fine-grained sandstone interbeds to 1 cm thick, dipping 30°; medium- to coarse-grained sandstone interbeds at 632 to 633 ft (192.6-192.9 m). 633-731 (192.9-222.8) Dense brittle dark-gray calcareous siltstone. Bedding shown by lighter colored 1 mm to 5 cm laminae every 10 to 30 cm, dips 0-25° (mostly 15°-20°). Below 664 ft (202.4 m), maximum thickness of light-colored laminae 2 cm; below 690 ft (210.3 m) maximum thickness 2 mm. Darker beds are carbonaceous. As much as 3 percent pyrite, disseminated and in thin films on fractures, maximum grain size 0.25 mm (much is smaller than 0.1 mm). Calcite veinlets to 3 mm wide with diverse orientations, about 15 to 20 per meter. At 641.5 to 641.8 ft (195.5-195.6 m) is breccia (fault zone or possible intrafonnational breccia) containing 20 to 30 percent pyrite; dip 10°. At 661.5 to 664 ft (201.6-202.4 m), is brecciated dolomitic siltstone (fault zone) with montmorillonite seams and montmorillonitic argillized matrix. Core broken and argillized at 677.8 to 680 ft (206.6-207.3 m), 681 to 682 ft (207.6-207.9 m), 684.7 to 685.7 ft (208.7-209.0 m), 694.5 to 695.3 ft (211.7- 211.9 m), 696.8-697 ft (212.4-212.45 m), 700.2-701 ft (213.4-213.7 m), 702 to 702.3 ft (214.0-214.1 m), 703 to 704 ft (214.3-214.6 m), 706 to 707 ft (215.2-215.5 m); upper contact dips 65°, 718.5 to 719 ft (219.0-219.2 m); irregular lower contact dips 70°, 720 to 723.5 ft (219.5-220.5 m), and 727.8 to 730 ft (221.8-222.5 m). Other argillized breccia zones at 682.5 ft (208.0 m; 3 cm thick), and 690.8 ft (210.6 m; probably intrafonnational, with calcite cement, dips 20°). At 680.5 to 690 ft (207.4-210.3 m) is probable fault zone; rock is intensely fractured and core recovery poor. Veins of clear dolomite(?) rhombs, some open, irregular, and vuggy, in interval 683 to 686.5 ft (208.2-209.2 m; dip 60°), and at 692.6 ft (211.1 m), 693 ft (211.2 m), 694.5 ft (211.7 m), 699 ft (213.1 m), 719.5 to 720 ft (219.3- 219.5 m; single 2-mm vein; dips 75°). In interval 714 to 719 ft (217.6-219.2 m), are small veinlets of yellow-brown calcitei montmorillonite with light-gray bleached halos to 2 cm diameter, 3 to 6 per meter. 731-736.5 (222.8-224.5) Soft black carbonaceous siltstone, probably argillized. Core intensely fractured and broken to crushed. Some fragments throughout show lighter colored and probably slightly coarser grained laminae to 5 mm thick (generally less than 2 mm). Pyrite, disseminated and as veinlets, less than 1 percent throughout. 736.5-748.4 (224.5-228.1) Fault breccia with abundant montmorillonite in cement. Poor core recovery. Lithology same as 731-736.5 ft.

748.4-790 (228.1-240.8) Lithology same as 731 to 736.5 ft. Beginning at 752.5 ft (229.4 m), many fractures have thin discontinuous white coating of clay (probably kaolinite), and locally fragments of core have network of irregular quartz veinlets less than 1 mm wide. Bedding intact at 755 to 755.3 ft (230.1-230.2 m), dips about 10° and shows penecontemporaneous deformation, including breakage, rotation, and some pull aparts of lighter colored laminae as much as 5 mm thick. Bedding also intact at 764.3 to 770.8 ft (232.9-234.9 m), dips roughly 25°, irregular, probably due to penecontemporaneous deformation. At 783 to 786.5 ft (238.6-239.7 m) bedding is warped, dips 20°-50°. Fault zone at 773.5 to 775 ft (235.8-236.2 m); only 20 cm of crushed core recovered. 790-813 (240.8-247.8) Fault zone. Lithology same as 731 to 790 ft. Only 70 cm crushed core recovered from this interval; material recovered probably represents harder breccia fragments in softer argillic matrix washed away by drilling fluid. 813-905 (247.8-275.8) Hard massive light-gray limestone, locally dolomitic. Calcite grain size generally 0.5 mm or less, few grains to 1 mm. Pyrite 0-0.1 percent as disseminated grains less than 0.25 mm diameter. Locally, where pyrite occurs in thin veinlets, total pyrite reaches about 1 percent. Between 813 and 855 ft (247.8-260.6 m), about 25 percent of core has abundant interbeds of sandstone and siltstone, in sections 15 cm to 1 m long. Silty beds have as much as 5 percent fine-grained disseminated pyrite. Massive limestone shows coarse bedding by slight color changes. Between 854 and 888 ft (260.3-270.7 m) are a few 1-cm-thick coarse marble beds (or veins?) with calcite crystals to several millimeters in diameter. Between 888.5 and 905 ft (270.8-275.8 m), rock has finely laminated appearance. At 898 to 905 ft (273.7-275.8 m) is medium-gray fine-grained silty limestone or calcareous siltstone with upper contact gradational over 1 m. Bedding dips 10°- 50°, mostly 30°-40°. Fractured or brecciated and altered at the following intervals: 813 to 815.5 ft (247.8-248.6 m), limestone and siltstone breccia with montmorillonite seams in matrix of siltstone breccia, locally with a network of quartz veinlets (<1 mm wide, and locally bleached and possibly kaolinite bearing, with lower contact dipping 25°); 819.4 to 820.3 ft (249.7-250.0 m), brecciated siltstone with montmorillonite seams in argillized matrix, and including 5 cm of soft white kaolinite(?)-rich material and 10 cm of fractured limestone with network of pyrite-bearing quartz veinlets (<1 mm wide), dips 30°- 40°; 821 to 821.8 ft (250.2-250.5 m), montmorillonite-bearing argillized fractured siltstone, dips 40°-50°; 822.5 ft (250.7 m), 3 cm same as 821 to 821.8 ft, dips 40°; 824 to 825.5 ft (251.1-251.6 m) and 826.3 to 827.5 ft (251.8-252.2 m), fractured limestone with montmorillonite-bearing pyrite-rich material along fractures and powdery white calcite on some fractures; 834.7 to 835.6 ft (254.4-254.7 m), 840.5 to 842.3 ft (256.2-256.7 m), 847.1 to 848.5 ft (258.2-258.6 m), 853 to 854 ft (260.0- 260.3 m), and 855.5 to 856 ft (260.7-260.9 m), intensely fractured to crushed soft light-gray argillized siltstone with montmorillonite seams, contacts irregular. Veinlets, in some cases forming networks, in following intervals: 815.5 to 819.4 ft (248.6-249.7 m), calcite veinlets, locally vuggy, to 2 mm wide; 819 to 830.5 ft (249.6-253.1 m) irregular wispy quartz veinlets <0.5 mm wide, with some pyrite,

becoming dense enough every 15 to 30 cm to form webby networks, and later generation of calcite veinlets to 1 mm wide; locally vuggy, 3 per meter; 830.5 to 838 ft (253.1-255.4 m), calcite veinlets to 2 mm, commonly vuggy, about 3 to 10 per meter; 832.7 to 833.1 ft (253.8-253.9 m) limestone breccia cemented by vuggy dolomite(?) in white rhombohedral crystals; 842.8 to 847 ft (256.9-258.2 m), irregular wispy dark-gray anhydrite veinlets, about 3 per meter; 849 to 852 ft (258.8-259.7 m) breccia cemented with vuggy dolomite(?); 852 to 853 ft (259.7- 260.0 m), some vuggy calcite veinlets; 854 to 888 ft (260.3-270.7 m) black pyrite- bearing quartz(?) veinlets, generally 5 to 10 per meter, and calcite veinlets, locally vuggy, 1 to 3 per 10 cm, in diverse orientations. 905-926 (275.8-282.2) Soft dark-gray to black mostly brecciated carbonaceous siltstone. Locally calcareous; includes fine-grained limestone with diversely oriented calcite veinlets at 908 to 910.5 ft (276.7-277.5 m). Larger siltstone fragments throughout contain calcite veins to 5 mm, occasionally 1 cm, wide. Bedding dips 20°-40°. Very fine grained disseminated pyrite less than 1 percent to 7 percent, relatively scarce in calcareous intervals. Brecciated from 906 to 906.5 ft (276.1- 276.3 m); limestone fragments in powdery to vuggy calcite matrix at 906.5 to 926 ft (276.3-282.2 m), probably a fault zone; calcareous siltstone fragments in argillic matrix at 915 to 918 ft (278.9-279.8 m); siltstone fragments, mostly calcareous at 918 to 926 ft (279.8-282.2 m). 926-942.5 (282.2-287.3) White soft to moderately hard medium-grained quartz monzonite. More or less argillized, with feldspar partly altered to clay, and 1 percent pyrite as disseminated grains to 0.5 mm. Pyrite tarnished, but limonite scarce. Upper contact is a fault, marked by breccia zone at 926 to 927.8 ft (282.2-282.8 m). Also crushed and brecciated zones at 932 to 933 ft (284.1-284.4 m) and 933.7 to 936.5 (284.6-285.4 m). All feldspar altered to clays at 927.8 to 932 ft (282.8-284.1 m). Below 932, partly altered plagioclase has pale yellow-green color. Between 929 and 932 ft (283.1-284.1 m) are two 1- to 3-mm-wide steeply dipping quartz- calcite veinlets with some pyrite. 942.5-963.7 (287.3-293.7) Pale- to medium-green, locally white, hard feldspar pegmatite, and some mica- rich molybdenite-bearing greisen, as noted below. Feldspar includes plagioclase laths to 1 cm which form subradiating clusters. Plagioclase is pale olive green, saussuritized throughout. Five to 20 percent fine-grained gray interstitial quartz, and 0 to 3 percent pyrite. Greisen at 943.5 to 943.9 ft (287.6-287.7 m) and 944.3 to 948 ft (287.8-288.9 m) has 30 to 40 percent pale-brown mica in books 3 mm in diameter, occasionally to 1 cm in diameter, in light-gray feldspar matrix. One to 3 percent disseminated pyrite grains <0.25 mm diameter. Similar greisen at 962.5 to 963.7 ft (293.4-293.7 m) has about 15 percent aggregates of fine grained molybdenite to 2 mm diameter. Calcite veinlets occur throughout, about 3 per foot (10 per meter) and a few quartz veinlets at 942.5 to 943.5 ft (287.3-287.6 m). Fractured with minor clay (montmorillonite?) and thin calcite crusts coating fractures, in following intervals: 947 to 949 ft (288.6-289.2

m), 951.5 to 952 ft (290.0-290.2 m), 953.7 to 954 ft (290.7 to 290.8 m), 958 to 959 ft (292.0-292.3 m). 963.7-975 (293.7-297.2) White soft to moderately hard medium-grained quartz monzonite. More or less strongly argillized, with as much as 1 percent pyrite, smaller than 0.25 mm, which forms scattered grains. Feldspar partly to completely altered except that potassium feldspar is only slightly altered at 970 to 973 ft (295.6-296.6 m). Contains calcite vemlets having diverse orientations, about 1 to 3 per foot (3-10 per meter). Mottled dark-gray and pink marble (grain size 1 mm) with 10 percent pyrite, as veinlets and patches, at 972.7 to 973.5 ft (296.5-296.7 m). Breccia zone at 974.5 to 975 ft (297.0-297.2 m), upper contact dips 50°. Lower contact irregular, dips about 40°. 975-1.044.5 (297.2-318.4) Pale-pink and pale-gray locally banded mottled marble (grain size generally 1 mm). Calcite veins common, pyrite scarce (no more than 1 percent seen locally in grains smaller than 0.25 mm). Locally quartz-bearing; quartz probably formed by replacement, contains as much as 50 percent pyrite. Quartz at following intervals: 980 to 980.3 ft (298.7-298.8 m), contains about 20 percent pyrite; 984.8 to 989.7 ft (300.2-301.6 m) contains 15 to 20 percent pyrite, 30 to 40 percent in 2-cm-thick zone at lower contact; 1,008.8 to 1010.0 ft (307.5-307.8 m), contains 30 to 40 percent pyrite. Crushed zones at: 989.7 to 997.5 ft (301.6-304.0 m), contains soft montmorillonitic zone at 990.8 to 992 ft (302.0-302.3 m); 1,002.0 to 1,004.5 ft (305.7-306.2 m); 1,007 to 1,007.5 ft (306.9-307.1 m); 1,016.0 to 1,018 ft (309.7-310.3 m). Pink mottling gradually disappears over interval 1,012 to 1,017 ft (308.4-310.0m). 1.044.5-1.048.5 (318.4-319.6) Brecciated gray fine-grained marble. Montmorillonite moderately abundant in matrix, contains 5 percent fine disseminated pyrite. 1.048.5-1.069(319.6-325.8) Hard medium-olive-green banded skarn. Banding dips 20°-70°. Calcite veins throughout in diverse orientations, some epidote veinlets. Soft argillic crushed zones 1053.5 to 1054.5 ft (321.1-321.4 m) and 1,067.8 to 1,069 ft (325.5-325.8 m). Few chalcopyrite grains at 1,062.8 ft (323.9 m). Molybdenite veins at 1,059 ft (322.8 m) and 1,066.3 to 1,069 ft (325.0-325.8 m); pyrite locally abundant (10-20 percent) in lower 2.2 ft (0.7 m). 1.069-1.085.5 (325.8-330.8) Hard to moderately soft pale-gray to white medium-grained biotite quartz monzonite, variably argillized. Relict texture good where orthoclase unaltered, otherwise poor. Soft breccia zone at 1,069 to 1,070.8 ft (325.8-326.4 m) is probably a fault. At 1,078.6 ft (328.6 m) is a 5-cm aplite dikelet, dips 45°. 1.085.5-1.121 (330.8-341.7) Soft white argillized biotite quartz monzonite. Feldspar altered to montmorillonite and potassium mica. Few wispy quartz veinlets; pyrite

generally less than 1 percent. Argillaceous seam at 1,103.1 ft (336.2 m) and 1,119.8 ft (341.3 m) with very fine grained pyrite. 1.121-1.142 (341.7-348.1) Hard to soft white to pale-gray biotite quartz monzonite, more or less argillized, harder zones propylitized. Pyrite generally less than 1 percent throughout, locally 1 to 2 percent. A few wispy quartz veinlets, less than 2 mm. 1.142-1.185 (348.1-361.2) Hard slightly propylitized biotite quartz monzonite. Potassium feldspar unaltered, generally pink; plagioclase gray, locally partially altered to chlorite or potassium mica; biotite fresh to totally altered to potassium mica or chlorite. Pyrite absent. 1.185-1.223 (361.2-372.8) Hard white to pale-gray weakly propylitized biotite quartz monzonite. Potassium feldspar and plagioclase generally partly altered to montmorillonite, biotite altered to chlorite or potassium mica. Pyrite disseminated, less than 1 percent. Upper and lower contacts with fresher quartz monzonite gradational over 1 ft (0.3 m). Small wispy quartz and (or) calcite veins every few feet. Few thin fractured or crushed zones. 1.223-1.341.5 (372.8-408.9) Hard slightly propylitized biotite quartz monzonite, similar to 1,142 to 1,185 ft (348.1-361.2 m) interval. Soft, crushed, argillized zones at 1,238.5 to 1,240 ft (377.5-377.9 m), 1,245.3 to 1,247 ft (379.6-380.1 m), 1,267 to 1,267.2 ft (386.2- 386.3 m), 1,267.6 to 1,267.7 ft (386.3-386.4 m), 1,267.9 to 1,270 ft (386.5-387.1 m), 1,272.5 to 1,273 ft (387.8-388.0 m), 1,277 to 1,285 ft (389.2-391.7 m), 1,301 to 1,304 ft (396.5-397.6 m), 1,330.4 to 1,333.8 ft (405.5-406.5 m). Little or no pyrite. Quartz veins, +/-pyrite, up to 3 cm, in intervals 1,223 to 1,236 ft (372.8-376.7 m), 1,267 to 1,285 ft (386.2-391.7 m), 1,294 to 1,301 ft (394.4-396.5 m), 1,304 to 1,340 ft (397.4-408.4 m); orientations diverse, but sets below 1,304 ft (397.4 m) dip 20° or less. 1.341.5-1.362.4 (408.9-415.2) Hard pale-green-purple propylitized andesite, probably a dike. Porphyritic, with 10 percent 1- to 5-mm plagioclase phenocrysts and 10 percent 1- to 2-mm mafic phenocrysts. Weakly to moderately fractured. Local soft argillized zones at 1,349 to 1,350.5 ft (411.2-411.6 m), 1,359 to 1,361.2 ft (414.2-414.9 m). Less than 1 percent pyrite scattered throughout, locally up to 5 percent. 1.362.4-1.448 (415.2-441.3) Very hard moderately propylitized biotite quartz monzonite. Pink potassium feldspar and gray plagioclase partially replaced by montmorillonite; biotite chloritized. Pyrite 0 to 0.5 percent. Quartz veinslpyrite, to 1 cm, occur every few feet throughout, typically have dips less than 20°. In interval 1,442-1,448 ft (439.5-441.3 m), rock becomes progressively more argillized, with feldspars replaced by montmorillonite and biotite by pyrite.

1.448-1.505 (441.3-458.7) Hard, propylitized, to soft, argillized, biotite quartz monzonite. Pyrite scarce.

DRILL HOLE USGS 2 Detailed description, intervals in feet (meters): 0-14 (0-4.3) Colluvium. 14-119 (4.3-36.3) Porphyritic andesite with 15 to 30 percent plagioclase phenocrysts to 1 mm. Flow breccia texture visible locally, otherwise massive. Few scattered vesicles, partly filled with calcite, adularia, and zeolites. Propylitized except for a few weak argillized areas 0.5 to 2 ft (15-61 cm) thick. Color greenish gray, grayish purple where hematite moderately abundant. Scattered veinlets, wisps, and blobs of calcite. Oxidized, with minor limonite on fractures. 119-160 (36.3-48.8) Porphyritic andesite flow breccia, locally with a few scattered vesicles. Propylitized, fractured, and weakly argillized; locally moderately strongly argillized. Color pale green due to removal of hematite by argillization. Locally propylitized only, not argillized, with calcite (±adularia) veins, wisps, and blobs, but calcite absent 130 to 160 ft (39.6-48.8 m). Limonite on scarce fractures. Soft core, moderately strongly argillized at 136.5-137 ft (41.6-41.8 m) and 142 to 144 ft (43.3-43.9 m). 160-296 (48.8-90.2) Porphyritic andesite flow breccia, same as above. Well-developed flow banding, 194 to 195 ft (59.1-59.4 m), dips 40°. Flow breccia texture patchy, 214 to 247 ft (65.2-75.3 m). Propylitized, medium bluish gray, locally medium greenish gray where hematite scarce. Plagioclase saussuritized, and groundmass bears chlorite and minor epidote. A few scattered hornblende phenocrysts, which look unaltered, appear locally. Very minor pyrite present, but limonite stain persists on fractures (rock partly oxidized). Calcite and minor adularia and zeolite veinlets, wisps, and blobs form as much as 1 percent of core. Slightly argillized, with pale-olive color, 197.5 to 199.5 ft (60.2-60.8 m), and 212.8 to 214.1 ft (64.9- 65.3 m). First coarse zeolite vein noted, 223.5 to 224.1 ft (68.1-68.3 m). Strongly crushed, with propylitized fragments in soft sandy moderately strongly argillized matrix, 290 to 296 ft (88.4-90.2 m). 296-365 (90.2-111.3) Porphyritic andesite same as above but massive with a few angular cognate fragments to 2 cm scattered throughout. Propylitized, medium greenish gray to medium bluish gray. Very minor pyrite and minor epidote throughout (rock unoxidized). Locally a few scattered slightly altered or unaltered hornblende phenocrysts. Much of core fractured; thin halos of weak argillization follow fractures. Veinlets and wisps of calcite, zeolites, and possibly adularia. 365-497 (111.3-151.5) Porphyritic andesite, same as above. Down to 478.5 ft (145.8 m), local vague mottling suggests poorly developed flow brecciation, and there are a few cognate

fragments to 1 cm. Several purplish zones 2 to 7 ft (0.6-2.1 m) thick, with somewhat larger and more abundant plagioclase phenocrysts, appear between 439.6 and 478.5 ft (134.0-145.8 m). Massive below 478.5 ft (145.8 m). Propylitized, grayish red purple. Plagioclase saussuritized, and minor epidote visible locally in groundmass. Scarce pyrite to 400 ft (121.9 m). Scattered calcite and adularia veinlets, and zeolite and calcite veinlets, blobs, and wisps. Fractures of diverse orientation throughout, with powdery calcite and kaolinite coating. Abundant zeolite and calcite pods and veins to 2 cm at 391.7 to 399 ft (119.4-121.6 m). Medium-red-purple zones 2 to 7 ft (0.6-2.1 m) thick, 402.5 to 478.5 ft (122.7-145.8 m), probably have less chlorite and more hematite. Calcite and zeolite veinlets are more abundant in red-purple material. Large vugs lined with quartz and calcite, 431.6-432 ft (131.6-131.7 m). Hornblende generally completely altered to epidote, 435 to 478.5 ft (132.6-145.8 m). From 478.5 to 497 ft (145.8-151.5 m), less hematite and more epidote than above. Epidote forms cores of saussuritized plagioclase, and partly replaces few scattered hornblende phenocrysts. Soft argillized rock with abundant montmorillonite seams, 478.5 to 479.5 ft (145.8-146.2 m). 497-572.5 (151.5-174.5) Porphyritic andesite. Massive, same as 478.5 to 497 ft. Few probable cognate fragments to 1 cm below 548 ft (167 m). Propylitized, medium greenish gray to light bluish gray, with disseminated chlorite and scattered 1-mm patches of epidote. Relict texture generally poor. Two to 5 percent pyrite starting at 504 ft (153.6 m). Few hornblende phenocrysts starting at 533 ft (162.5 m), appear unaltered to 543 ft (165.5 m), but partly converted to pyrite below 543 ft (165.5 m). Few veinlets of zeolite and minor calcite. Fractures coated with powdery calcite and kaolinite, and small amounts of chlorite(?) occur on the walls of some. Argillized, crushed core, with seams of chlorite(?) along fractures, 497 to 506 ft (151.5-154.2 m) and 512 to 516.5 ft (156.1-157.4 m). 572.5-613 (174.5-186.8) Same as above, massive. Weakly argillized, moderately hard but fractured, with many zones of crushed core. Minor clay on some fractures. Relict texture poor. Five percent pyrite, locally partly converted to limonite (rock partly oxidized). Few blobs of quartz, yellow calcite, and montmorillonite. 613-675 (186.8-205.7) Same as above. Argillized, light gray to light bluish gray or light greenish gray. Strongly fractured to crushed throughout, soft to 640 ft (195.1 m) and below 664 ft (202.4 m), moderately hard mainly due to more abundant calcite from 640 ft (195.1 m) to 664 ft (202.4 m). Montmorillonite seams along fractures in soft areas. Scattered empty vugs in harder areas. Relict texture moderately good to poor. One to 5 percent p>rite, some probably replaces former hornblende phenocrysts; limonite halos on some pyrite grains. Propylitized from 659.5 ft (201.0 m) to 660.5 ft (201.3 m); hard, grayish red purple. Both upper and lower contacts gradational over 3 ft (1.0 m).

675-796 (205.7-242.6) Porphyritic andesite flow breccia. Argillized, mostly moderately hard to 738 ft (224.9 m), mostly soft 738 ft to 768 ft (224.9-234.1 m), mostly moderately hard (due to more abundant calcite) 768 ft to 789 ft (234.1-240.5 m), mostly soft 789 ft to 796 ft (240.5-242.6 m), otherwise same as above. Several pockets as much as 1 cm in diameter, filled with kaolinite, 704 ft to 705 ft (214.6-214.9 m). From 738 ft to 768 ft (224.9-234.1 m), light greenish gray. Calcite, chlorite, pyrite, and minor epidote replace former hornblende phenocrysts at several spots. Fractures are coated with a thin crust of powdery white material containing minor calcite. 796-853 (242.6-260.0) Porphyritic andesite. Flow breccia texture gradually dies out, absent below 807.5 ft (246.1 m). Only a few scattered cognate fragments persist to 832 ft (253.6 m). Argillized and propylitized, light to medium bluish gray, locally pale green. Relict texture generally poor to absent. Mostly hard, but moderately hard to soft 807.5 to 832 ft (246.1-253.6 m). Montmorillonite seams in soft areas, powdery crusts with minor calcite on fractures in hard areas. Small spots of limonite on some fractures. Two to 7 percent pyrite, some replacing hornblende along with leucoxene or chlorite. Locally, networks of small quartz veinlets with minor pyrite. 853-899 (260.0-274.0) Porphyritic andesite flow breccia. Flow breccia texture dies out from 870 to 899 ft (265.2-274.0 m). Argillized, light bluish or greenish gray to medium bluish gray. Moderately hard, strongly fractured; much crushed core below 870 ft (265.2 m), with montmorillonite and rare zeolites on fractures. Relict texture generally poor, but locally good. Two to 3 percent pyrite. Hornblende phenocrysts rarely visible, converted to chlorite and pyrite. Locally few quartz phenocrysts or xenocrysts. 899-948 (274.0-288.9) Porphyritic andesite. Massive except for 3-inch-thick flow breccia zones at 916.5 ft (279.3 m) (dip 40°) and 938.8 ft (286.1 m) (dip 60°). Propylitized, light to medium bluish gray. Fractured at several spots as much as 3 ft (90 cm) wide, with limonite patches on fractures. Several 1.5- to 3-ft (0.5-0.9-m) wide patches are weakly argillized. Poor relict texture. Five percent pyrite. The few scattered hornblende phenocrysts are converted to chlorite/montmorillonite, calcite, and pyrite to 934 ft (284.7 m); below 934 ft (284.7 m) they are unaltered or have minor epidote. Yellow and white zeolite and calcite veinlets, wisps, and blobs throughout. 948-971.5 (288.9-296.1) Porphyritic andesite flow breccia. Propylitizied and argillized, light bluish gray. Argillized 948 to 953 ft (288.9-290.5 m) and 968.5 to 971.5 ft (295.2-296.1 m), otherwise propylitized and argillized. Relict texture poor to moderately good. Three to 5 percent pyrite. Some scattered 1- to 2-mm limonite-stained spots at 948 to 953 ft (288.9-290.5 m) are converted to pyrite and black material (magnetite?). Calcite and (or) zeolite veinlets throughout.

971.5-1.006.5 (296.1-306.8) Andesitic lapilli tuff with abundant 1 mm to 6 cm angular to subrounded porphyritic andesite fragments. Every few feet, 0.5 to 2 ft (15-60 cm) bedded intervals appear. Bedding is produced by laminae of fine to coarse ash with a few lapilli-size fragments. Sharp upper contact dips 40°. Propylitized and argillized, medium bluish gray. Five percent pyrite. Some larger fragments have several percent mafic minerals, converted to pyrite and black material (magnetite? and calcite). 1.006.5-1.016 (306.8-309.7) Porphyritic andesite with poorly developed flow breccia texture. Upper contact sharp, dips 55° to 60°. Similar to andesite above 971.5 ft (296.1 m), except hornblende phenocrysts smaller (less than 2 mm) and scarcer. Propylitized, light gray. Moderately good relict texture. Five percent pyrite. Five percent mafic minerals, probably hornblende, converted to pyrite and black material (magnetite?). Zeolite veinlets throughout. 1.016-1.100 (309.7-335.3) Porphyritic andesite tufH?). Down to 1,055.5 ft (321.7 m) plagioclase phenocryst content is relatively high (25-30 percent), and the rock has a sandy appearance: it is probably a coarse andesitic crystal tuff instead of a flow. From 1,055.5 to 1,079.5 ft (321.7-329.0 m) is poorly developed flow breccia with only a few cognate fragments to 1 cm, in interval from 1,061 ft to 1,073.5 ft (323.4-327.2 m). Below 1,079.5 ft (329.0 m), flow breccia texture is generally well developed. Argillized, light gray to bluish gray, and below 1,080 ft (329.2 m), light greenish gray. Moderately soft, strongly fractured, crushed in many places down to 1,055.5 ft (321.7 m). Moderately hard (due to more abundant calcite) below 1,055.5 ft (321.7 m). Moderately good relict texture. Two to 5 percent pyrite, and locally a few 1- to 2-mm-diameter patches of limonite stain. Hornblende altered to dark-grayish-green montmorillonite and minor pyrite and epidote to 1,055.5 (321.7 m), and to pale-olive-green chlorite/montmorillonite and minor pyrite below 1,055.5 (321.7 m); hornblende very scarce below 1,071 ft (326.4 m). 1.100-1.134.5 (335.3-345.8) Porphyritic andesite flow breccia. Argillized, very light gray to light gray. Mostly very soft, with poor relict texture. Five percent pyrite, with a few 1- to 2- mm limonite-stained spots. Few percent mafics, altered to chlorite and (or) montmorillonite plus minor pyrite. Montmorillonite seams common. 1.134.5-1.158 (345.8-352.9) Aphanitic to porhyritic andesite, probably a different flow from that above. Flow banding at top of flow, 1,134.5 to 1,135 ft (345.8-345.9 m), dips 20° to 30°. Poorly developed flow breccia texture at 1,137 to 1,137.7 ft (346.5-346.8 m). Flow is aphanitic at top; phenocrysts become gradually coarser with depth, reaching maximum phenocryst size at 1,156 ft (352.3 m), with 2-mm plagioclase phenocrysts (some to 4-5 mm) forming 25 percent of rock. Propylitized, medium bluish gray, to argillized, light gray. Propylitized and argillized rock form alternating zones 0.5 ft (15 cm) to 8 ft (2.4 m) wide. Intensely fractured where propylitized, crushed where argillized. Pyrite ranges from very scarce to as

much as 5 percent. Relict texture poor to very good (best in propylitized areas, with plagioclase nearly fresh to saussuritized). Veinlets of calcite, and calcite±clay(?) in propylitized rock. Argillized rock bears montmorillonite seams. 1.158-1.164 (352.9-354.8) No core. Probable fault zone. 1.164-1.265 (354.8-385.6) Porphyritic andesite, massive except for flow banding at 1,183.8 ft (360.8 m) (dip 30°), 1,194.5 to 1,196 ft (364.0-364.5 m) (dip 40°), and 1,262.5 ft (384.8 m) (dip 25°-30°), and poorly developed flow breccia at 1,233.8 to 1,237.5 ft (376.1-377.2 m), and 1,264.8 to 1,265 ft (385.5-385.6 m) (dip 25°). Finer grained than above material, with most plagioclase phenocrysts less than 1 mm diameter. Mafics and opaques total 5 percent or less, are very fine grained (less than 0.1 mm), and are observed only locally. Texture of above interval grades into this interval, 1,164 to 1,168 ft (354.8-356.0 m). Plagioclase and mafics become slightly coarser again, 1,233 to 1,265 ft (375.8-385.6 m). Dominantly propylitized in upper part, medium bluish gray to pale red purple, grading to dominantly argillized in lower part, light greenish gray. Bluish to purplish color in propylitized material is due to disseminated hematite. Good relict texture to 1,205.5 ft (367.4 m), poor to 1,223 ft (372.8 m), generally good below. In propylitized rock, plagioclase is nearly fresh and pyrite is absent above 1,181.5 ft (360.1 m). Below 1,181.5 ft (360.1 m), plagioclase saussuritized, rock has some small epidote patches (0.5 mm) and 3 to 5 percent pyrite. Where hematite is abundant (red-purple color), pyrite is scarce. Below 1,233 ft (375.8 m), mafics are converted to dark-green chlorite. Veinlets and vugs (to 2 cm) in propylitized rock are filled with calcite, quartz, and zeolite. Down to 1,197 ft (364.8 m) are several fractured and argillized zones, 1 to 7 ft (30 cm-2.1 m) thick. Argillization along 2- to 3-cm-thick crushed zones at 1,177 ft (358.7 m) (dip 65°-70°) and 1,184 ft (360.9 m) (dip 30°). Argillized rock predominant over propylitized rock in intervals 1,197 to 1,205.5 ft (364.8-367.4 m), and 1,223 to 1,265 ft (372.8 to 385.6 m), forming 0.5- to 3.5-ft (15 cm-1.1 m)-thick zones of soft core with abundant montmorillonite seams. Few gypsum veinlets, 1,262 ft to 1,265 ft (384.6-385.6 m). 1.265-1.278.5 (385.6-389.7) Fine-grained rhyodacitic vitric-crystal tuff, with 20 percent plagioclase and quartz crystals as much as 2 mm diameter in a fine tuff matrix. Bedding shown by 1- to 3-in. (3-8 cm) layers of finer grained, better sorted tuff (plagioclase crystals to 1 mm) every few inches to 1 ft (30 cm), and a few coarser, more poorly sorted beds with some aphanitic lithic fragments to 1 cm (dip 20°-30°). Last 1.3 ft (40 cm) of interval contains two beds of rhyodacitic lapilli tuff containing quartz and plagioclase crystals and andesitic lithic fragments. Argillized, medium to dark gray. Dark-gray areas (predominant) are soft, have about 1 percent very fine grained disseminated pyrite (less than 0.1 mm), and abundant black montmorillonite seams. Medium-gray areas are moderately hard, have 5 to 10 percent pyrite. Relict texture good in medium-gray areas, poor in dark- gray areas.

1.278.5-1.337.5 (389.7-407.7) Rhyodacitic lapilli tuff, very poorly sorted, with 20 percent fragments 4 mm to 4 cm diameter (most are less than 1.5 cm), including aphanitic and porphyritic volcanics, siliceous argillite (Palmetto Formation), and a few fragments of lithic- crystal tuff or volcanic sandstone. Matrix is fine ash with 30 percent coarse ash- size crystals, mostly feldspar, with as much as 5 percent of the coarse ash fraction being quartz. Local variations in sorting and maximum clast size reveal crude bedding, dips 30°-35°. Argillized, medium-gray, soft, and montmorillonite- bearing. One percent or less pyrite, very fine grained (less than 0.1 mm). 1.337.5-1.386 (407.7-422.4) Mostly fine rhyodacitic tuff. Lapilli tuff texture is locally visible to 1,347 ft (410.6 m), and at 1,371 ft to 1,376.5 ft (417.9-419.5 m). Some coarse tuff with several inch-thick lapilli tuff interbeds (same as coarse tuffs and lapilli tuffs described in the two previous intervals, 1,390 to 1,395 ft (423.7-425.2 m). Argillized, medium gray, soft, with abundant montmorillonite forming closely spaced seams that obscure relict texture. One percent or less pyrite, very fine grained, as above. 1.386-1.395 (422.4-425.2) Mostly tuffaceous rocks same as 1,400.5 to 1,420 ft (426.9-432.8 m) (see below). Bedding at 1,392 ft (424.3 m) dips 50°. Upper contact placed at first conglomerate bed. Interbeds of material similar to above interval at 1,390 to 1,391.5 ft (423.7-424.1 m) and 1,393 to 1,394 ft (424.6-424.9 m). Argillized, medium gray, soft, with abundant montmorillonite forming closely spaced seams obscuring original textures. Pyrite less than or equal to 1 percent and very fine grained, as above. 1.395-1.400.5 (425.2-426.9) Amygdular porphyritic andesite with several inclusions of tuffaceous(?) volcanic sandstone and conglomerate (same as next interval below) varying from 1 cm to 10 cm: several of the larger ones occupy the entire core at 1,395.5 ft (425.3 m), 1,396 ft (425.5 m), and 1,397 ft (425.8 m). A partially fused quartz monzonite inclusion occurs as 1,399.5 to 1,400 ft (426.6-426.7 m). Stretched and alined amygdules at 1,398 (426.1 m) show flow orientation, dip 40°. Probably a dike or sill. Propylitized, light bluish gray, with altered plagioclase and small mafic grains (less than 0.5 mm) converted to chlorite, but tuffaceous(?) sedimentary rock inclusions appear to be argillized, medium gray. Strongly fractured to crushed throughout. Pyrite scarce. Amygdules filled with calcite and quartz. 1.400.5-1.420 (426.9-432.8) Bedded fine rhyodacitic tuff to very coarse tuffaceous sandstone and conglomerate. Individual beds range in thickness from 0.5 in. to 1 ft (1-30 cm), the coarser beds being thicker. Sorting relatively poor throughout except for thin fine tuff beds. Clasts are 20 to 30 percent quartz, 15 to 30 percent feldspar, and 40 to 60 percent or more lithics, mainly aphanitic and porphyritic volcanics, plus a minority of chert and siliceous argillite fragments (Palmetto Formation) and a few possible fine-grained granitic fragments. Bedding attitude is quite variable: sedimentary structures that produce the variation include probable

crossbedding, loading structures around large clasts, and small folds, some recumbent, probably due to downslope movement. Argillized, medium light gray. Pyrite scarce in beds with coarse relict texture, but several percent very fine grained disseminated pyrite occurs in beds with fine-grained relict texture. Montmorillonite forms a few seams, and is abundant in tuff beds and in matrix of coarser sediments. Crushed zones 1.5 ft (46 cm) thick at 0.5- to 5-ft (15 cm-1.5 m) intervals throughout. 1.420-1.437 (432.8-438.0) Tuff and epiclastic rocks, same as above. Argillized, medium gray, soft, with abundant montmorillonite forming networks of seams in matrix around relict clasts. Strongly fractured. One percent very fine grained disseminated pyrite. Upper contact gradational over 1 ft (30 cm). Crushed core, 1,436 to 1,437 ft (437.7-438.0 m). 1.437-1.439 (438.0-438.6) Prophyritic andesite with a few amygdules. Looks very similar to andesite at 1,395 to 1,400.5 ft (425.2-426.9 m). May be another dike or sill. Propylitized, light bluish gray. Hard, strongly fractured; moderately good relict texture. Plagioclase altered to montmorillonite and calcite, with minor chlorite; mafics converted to pyrite and calcite. Few scattered amygdules are filled with calcite and quartz.

DRILL HOLE USGS 3 Detailed description, intervals in feet (meters): Q-1Q (Q-3.0) Colluvium. 10-94.5 (3.1-28.8) Hard dark-bluish-gray propylitized rhyodacite, with 25 percent saussuritized plagioclase phenocrysts (1-2 mm, few to 4 mm), 7 to 10 percent brassy biotite plus altered hornblende (with hematite rims) phenocrysts (0.5 mm), and 1 to 2 percent rounded, corroded, quartz phenocrysts (1-2 mm, locally to 4 mm; scarce below 28 ft (8.5 m)); biotite becomes coarser with depth (to 1 mm, below 50 ft (15.2 m)). Scattered white rounded fine-grained inclusions to 1 cm occur throughout. Flow breccia zone at 36 to 46 ft (11.0-14.0 m), bounded at bottom by 1-cm-thick flow band dipping 50°. Calcite veinlets, with diverse orientations, throughout; vugs common, up to 5 cm. Flow(?) breccia zones at 21.3 to 27 ft (6.5- 8.2 m), 34 to 35 ft (10.4-10.7 m), 48 to 49.5 ft (14.6-15.1 m), 51.5 to 53 ft (15.7- 16.2 m), and 60 to 94.5 ft (18.3-28.8 m) intervals healed with dark-green chlorite, quartz, calcite, and hematite. 94.5-120.5 (28.8-36.7) Hard more or less intensely fractured to soft crushed propylitized to somewhat argillized rhyodacite with olive-brown to yellow color due to variable limonite. Plagioclase variably altered to montmorillonite; mafics altered to limonite, black goethite, leucoxene and chlorite(?). In 94.5-106.5 ft (28.8-32.5 m) interval, vugs to 2 cm, lined with calcite. 120.5-156.5 (36.7-47.7) Hard locally fractured medium-bluish to greenish-gray propylitized rhyodacite flow breccia. Discrete breccia zones between 121 and 136 ft (36.9-41.5 m) dip 40°-60°. A few 1-cm fine-grained inclusions scattered throughout. Plagioclase saussuritized; hornblende altered to leucoxene+limonite, and rimmed by hematite; biotite replaced by yellow to white potassium mica; 1 to 2 percent hematite grains in groundmass replacing opaques; scarce quartz phenocrysts are unaffected by alteration. Groundmass pale purple to green depending on hematite content. Below 145.5 ft (44.3 m) are several strongly fractured zones up to 70 cm thick. Below 148 ft (45.1 m), relict texture locally poor, possibly due to strong propylitization and weak argillization combined; this represents transition to next interval below. 156.5-172 (47.7-52.4) Hard medium-grayish-grsen propylitized rhyodacite, relict texture good to poor. Upper contact at point where groundmass hematite is no longer apparent. Locally strongly fractured with fracture coatings of limonite and montmorillonite. Patchy limonite stain throughout. Few scattered vugs to 1 cm, lined with calcite.

172-214 (52.4-65.2) Moderately hard to moderately soft propylitized rhyodacite with many soft argillized zones. Moderately good relict texture. Plagioclase saussuritized to argillized. Abundant limonite forming stains and patches, probably replacing mafics. Softest areas are crushed, form about one-third of core in zones 2 cm to 1.0 m thick. About 25 percent of rock below 204 ft (62.2 m) is unoxidized, in patches with sharp contacts, containing 3 to 5 percent pyrite (to 0.25 mm) scattered throughout. 214-220.5 (65.2-67.2) Hard pale-greenish-gray propylitized and argillized rhyodacite with good relict texture. Plagioclase, 20 to 25 percent, up to 5 mm, saussuritized to argillized; biotite, about 0.5 mm, altered to potassium mica or montmorillonite and leucoxene; hornblende, about 0.5 mm, altered to leucoxene; scarce quartz. As much as 3 percent pyrite scattered through groundmass. 220.5-243.8 (67.2-74.3) Soft crushed to moderately hard argillized and propylitized rhyodacite. Plagioclase extensively altered to montmorillonite and calcite. Softer material contains numerous montmorillonite seams. Generally 2 percent pyrite as scattered grains or aggregates, to 0.5 mm. Minor limonite stains at 220.5 to 223 ft (67.2-68.0 m), 227.3 ft (69.3 m), and 241.5 to 243.6 ft (73.6-74.2 m). 243.8-249.5 (74.3-76.0) Moderately hard fractured pale-gray propylitized and argillized rhyodacite. Plagioclase saussuritized, 20 percent, generally less than 2 mm; biotite, 5 percent, 0.25 to 1 mm, altered to potassium mica±hematite; few percent altered hornblende. Two percent pyrite (to 0.5 mm) and 2 percent hematite (replacing opaques?). 249.5-289(76.0-88.1) Hard fractured to soft crushed propylitized and argillized rhyodacite. Plagioclase phenocrysts to 2 mm, 30 to 35 percent; biotite to 0.5 mm, less than 5 percent; scarce quartz. Two percent pyrite, less than 0.5 mm; 1 percent hematite. Fine- grained mafic inclusion at 275.8 ft (84.1 m), rounded, with black iron oxide(?) replacing originally abundant hornblende(?); additional inclusions at 263.3 ft (80.3 m). Calcite-lined vugs at 272 to 274 ft (82.9-83.5 m). Montmorillonite seams locally abundant in interval 258.4 to 285.5 ft (78.8-87.0 m). 289-326 (88.1-99.4) Hard pale-purple to blue (nearly white) propylitized to argillized rhyodacite; dacite flow breccia at 307 to 309 ft (93.6-94.2 m) and 314 to 326 ft (95.7-99.4 m). Relict texture poor. Pyrite 1 to 5 percent, generally 2 to 3 percent, in cubes to 0.5 mm. Thin wispy quartz veinlets to 1 mm, scattered throughout. Fine-grained mafic inclusions at 291 to 293 ft (88.7-89.3 m) and 309 to 326 ft (94.2-99.4 m). Montmorillonite seams common from 294 to 307 ft (89.6-93.6 m).

326-351 (99.4-107.0) Soft but generally intact white to light-gray argillized rhyodacite. Relict texture poor. One to 3 percent pyrite (to 0.25 mm); 1 percent hematite (to 0.5 mm). Large vugs in interval 326 to 332 ft (99.4-101.2 m). 351-365 (107.0-111.3) Moderately hard weakly to moderately fractured white argillized rhyodacite flow breccia. Relict texture poor. 365-381 (111.3-116.1) Soft locally crushed, to hard intensely fractured white to pale-green argillized to propylitized rhyodacite. Pyrite 2 to 3 percent, hematite very minor. 381-383 (116.1-116.7) Fault zone(?), poor core recovery. 383-394.8 (116.7-120.3) Hard locally strongly fractured, argillized and propylitized rhyodacite flow breccia. Plagioclase phenocrysts, 30 percent, to 1.5 mm but a few to 1 cm, altered to montmorillonite or potassium mica; biotite, 3 to 5 percent, generally less than 0.5 mm, altered to leucoxene, pyrite, hematite; hornblende 3 to 10 percent, to 2 mm, altered to potassium mica+pyrite. Quartz to 1 mm, scarce. Groundmass mottled pale green and purple. Pyrite generally about 5 percent. Rock near bottom of interval fine grained, more strongly fractured. Few fractures, generally 75° to 90°, have pale-green montmorillonite and minor calcite. 394.8-396 (120.3-120.7) Soft but mostly intact montmorillonitic volcanic conglomerate; poorly sorted, with 20 to 30 percent clasts (2 mm to 5 cm; generally less than 1 cm), including white, green, and medium-gray aphanitic silicic to intermediate) volcanic rocks, 5 to 10 percent porphyritic andesite and (or) latite fragments, and about 10 percent black siliceous shale or argillite and medium-gray to brown chert fragments (Palmetto Formation). Most fragments angular to subangular, but some argillite clasts are rounded/subrounded. Matrix is coarse sand: 50 percent quartz or chert, 15 to 20 percent feldspar, 30 percent lithics. Pyrite less than 1 percent. Vague bedding dips 40°-45° at 395 to 395.5 ft (120.4-120.5 m) and 40° at 401.5 to 402 ft (122.4-122.5 m). Interbeds of fine tuffaceous sandstone and siltstone occur at 394.8 to 395 ft (120.3-120.4 m) and 395.8 to 396 ft (120.6-120.7 m). Core broken, possibly due to fault, at 394.8 ft (120.3 m) and 396 ft (120.7 m). 396-399 (120.7-121.6) Soft generally intact but locally crushed argillized latitic tuff. Relict texture very poor. Plagioclase phenocrysts 25 to 30 percent or more, to 2 mm; biotite 10 percent or more; euhedral, to 1 mm; no hornblende or quartz. Pyrite generally 3 percent, to 0.25 mm, but locally to 10 percent. Montmorillonite seams abundant. Bedding indicated by green streaks and vague relict foliation at 396 to 397 ft (120.7-121.0 m): 40°. Possibly part of the Kendall Tuff.

399-4Q4.3 (121.6-123.2) Soft argillized volcanic conglomerate, essentially identical to interval at 394.8 to 396 ft (120.3-120.7 m). Bedding at 401.5 and 402 ft (122.4-122.5 m) dips 40°. 404.3-421.6 (123.2-128.5) Soft argillized latite tuff, essentially identical to interval at 396 to 399 ft (120.7- 121.6 m). Bedding at 408 to 409 ft (124.4-124.7 m) dips 40°-50°; at 409 to 410.5 ft (124.7-125.1 m) dips 60° to 70°; at 411.5 to 413 ft (125.4-125.9 m) dips 40° to 55°. Interval 416.8 to 421.6 ft (127.0-128.5 m) completely crushed, has 7 percent pyrite and abundant montmorillonite seams with low dips (parallel to bedding?). At 420 ft (128.0 m) is 15-cm dark-green zone with abundant coarse pyrite as fracture coatings (large mafic fragment in tuff?). 421.6-423 (128.5-128.9) Soft volcanic conglomerate with abundant montmorillonite-coated fractures. Intact in middle, crushed at top and bottom of interval. 423-424 (128.9-129.2) Hard broken medium-green propylitized latite tufft?) with abundant biotite altered to pale-pink potassium-mica+hematite. 424-428.4 (129.2-130.6) Soft montmorillonite-rich fault breccia containing fragments of volcanic conglomerate and latite tufft?). 428.4-437 (130.6-133.2) Very soft but intact argillized latite tuff. Montmorillonite seams very abundant. Vague green splotches at 428.4 to 430.5 ft (130.6-131.2 m) may be cognate latite lapilli. Biotite locally abundant (20 percent) below 430.5 ft (131.2 m) and rock is similar to crystal tuffs northeast of Banner Mountain. Pyrite about 3 percent, less than 0.25 mm. Interval 430.5 to 437 ft (131.2-133.2 m) brecciated, probably due to faulting. 437-449 (133.2-136.9) Hard pale-green propylitized and argillized rhyodacite. Intense fracturing at 437 to 443 ft (133.2-135.0 m), somewhat less intense below 443. Plagioclase phenocrysts about 20 to 25 percent, to 1.5 mm (few to 4-5 mm); biotite, 5 percent, generally less than 0.5 mm; hornblende, 2 to 5 percent, mostly less than 1 mm; quartz very rare. Pyrite, 3 percent to 0.25 mm. Patchy calcite coatings on some fractures. 449-452 (136.9-137.8) Very soft montmorillonite-rich latitic crystal tufK?) with 20 percent or more plagioclase phenocrysts (to 1 mm) and up to 20 percent biotite (to 2 mm). Granitic fragment at 451.9 ft (137.7 m). 452-452.5 (137.8-138.0) Fault zone with massive coarse polycrystalline quartz and minor calcite. Two zones, 5 cm thick, separated by 2 to 3 cm of dark-gray montmorillonitic breccia;

all probably part of a granitic fragment from overlying latite tuff caught up in fault zone. About 3 percent pyrite. 452.5-457 (138.0-139.3) Hard, intensely fractured, pale-green to white, propylitized and argillized latite. Relict texture very poor, no quartz apparent. Thirty percent saussuritized plagioclase phenocrysts, 5 percent biotite altered to calcite. Pyrite about 3 percent to 0.25 mm.

PETROGRAPHIC DATA METHODS OF INVESTIGATION We examined all samples by transmitted-light optical methods, using standard thin sections. To identify fine-grained secondary minerals, we subjected most samples to X-ray diffraction analysis. We obtained X-ray patterns using a diffractometer with output to a chart recorder. The emphasis in our study was to identify all minerals present, not to quantify abundances of major minerals. Consequently, we did not employ any methods meant to provide quantitative or semi-quantitative estimates of mineral abundances. RESULTS Drill hole USGS 1 penetrates rhyodacite, andesite, and latite flows of the Tertiary section, then siltstone and limestone of the Palmetto Formation of Ordovician age, and finally intrusive quartz monzonite of Late Jurassic age. Near the intrusive contact, the quartz monzonite contains some pegmatite and greisen. An andesite dike cuts the quartz monzonite. This dike is not clearly related to any flow in the overlying Tertiary section. Drill holes USGS 2 and 3 penetrate mainly volcanic rocks, including flows and tuffs of andesitic, rhyodacitic, and latitic composition. Conglomerate and sandstone seen in USGS 2 and 3 contain lithic clasts mainly of volcanic origin. The pre-Tertiary sedimentary rocks penetrated in USGS 1 probably were subjected to regional greenschist-facies metamorphic conditions, and rocks near the quartz monzonite also underwent contact metamorphism. Hydrothermal activity produced argillic alteration, and probably at least some of the propylitic alteration that affects numerous intervals throughout all three drill holes. This hydrothermal alteration accompanied volcanism in Early Miocene time (Ashley and Silberman, 1976). Some propylitic alteration in both the quartz monzonite and Tertiary flows, however, may pre-date the main hydrothermal event. Paleozoic rocks in southwestern Nevada generally show greenschist-facies mineral assemblages, leading us to infer that chlorite, mica, and possibly some clay in the siltstone of USGS 1 probably was formed during regional metamorphism, but it is difficult to discriminate between metamorphic and hydrothermal minerals in these rocks. Limestone in USGS 1 is all more or less recrystallized, the result of both regional and contact metamorphism. In addition, the quartz monzonite contains an inclusion of skarn showing copper and molybdenum mineralization. The petrographic data are given in the tables that follow. Because we have only qualitative estimates of mineral abundances, both primary and secondary minerals are listed in approximate order of decreasing abundance. The lists of primary and secondary minerals for each sample are independent of each other, so the most abundant secondary mineral in a sample may, for example, be more or less abundant than the most abundant primary mineral in the same sample. In rocks showing strong or intense alteration, the primary minerals, with the exception of quartz, are entirely altered, so the primary minerals shown represent the mineral assemblage inferred for the original rock, prior to alteration.

Table 5. Petrographic data for thin sections taken from Goldfield Drill Hole USGS 1. [Alteration types: P, propylitic; A, argillic. W, weak alteration; most primary minerals remain. M, moderate alteration; groundmass largely to completely altered, and phenocrysts partly altered. S, strong alteration; no primary minerals remain but original textures preserved. I, intense alteration; primary minerals and textures completely obliterated. Mineral species codes are: Ab, albite; Any, anhydrite; B, biotite; Ba, barite; Brl, beryl; Cbn, carbonaceous material; Cc, calcite; Chb, chabazite; Chl, chlorite; Cor, corundum; Cpx, clinopyroxene (diopsite/augite); Dia, diaspore; Dol, dolomite; Ep, epidote; F, feldspar; G, goethite; Hbl, hornblende; Hem, hematite; J, jarosite; K, kaolinite; Kfa, adularia; Kfo, orthoclase; Kfs, sanidine; Km, potassium mica (includes muscovite); Lm, laumontite; Lx, leucoxene; M, montmorillonite; Mf, mafics, species indeterminant due to alteration; Mt, magnetite; Opx, orthopyroxene; PI, plagioclase; Py, pyrite; Q, quartz; Sph, sphene; Vv, vesuvianite; Z, zeolite. Numbers in parentheses () are visual estimates of modal percentages and refer to phenocrysts only; tr, trace; (vein), mineral is restricted to veins] Depth ft m Rock type Rhyodacite do. do. do. do. do. Andesite do. do. do. Latite do. do. do. do. do. do. do. do. do. do. Alteration type A A A A P P A P P A P P P P,A A P P,A P,A P,A P,A P Degree of Alteration S S S S M W M S W S S S S S M S S S S Primary minerals (in order of decreasing abundance) Pl(15),Mf(10),Q,(l),Mt(l) Pl(15),Mf(12),Q(2),Mt(l) Pl(20),Mf(6),Q(2),Mt(l) Pl(10),Mf(4),Q(2),Mt(l) Pl(10),Mf(10),Q(2),Mt(l) PI (10), Hbl (6), B (4), Q (3), Mt(l),Cpx(l) PI (20), Mf (10) Pl(15),Mf(3) Pl(20),Mf(10),Mt(2) Pl,Mf Pl(25),Mf(8) Pl(20),Mf(5) Pl(17),Mf(6) Pl(15),Mf(6) Pl,Mf PI (10), B (4), Hbl (2) Pl,Mf Pl(15),Mf(10),Mt(l) Pl(20),Mf(4),Mt(l),Kfs? (tr) Pl(18),Mf(10),Mt(l) Pl(15),Mf(5) Secondary minerals (in order of decreasing abundance) M, Q, Km, Hem, Lx, Sph, G M, Q, Py, Km, Sph, Lx M, Q, Km, Py, Lx, Sph M, Q, Py, Km, Lx Chl, Q, Mt, Lx, Cc, Hem Chl, Cc, Lx, Mt M, Py, Cc, Lx M, Ab, Cc, Py, Lx, Chl Chl, Cc, Hem, K(?), Ab M, Chl, Ab, Cc, Q, Lx, Kfa M, Q, Chl, Ab, Hem M, Q, Chl, Ab, Hem M, Q, Chl, Cc, Lx, Py, Hem, Kfa M, Q, Ab, Chl, Km, Py M, Q, Chl, Ab, Km, Py M, Q, Ab, Cc, Chl, Py, Km, G M, Q, Py, Km, Chl, G M, Ab, Cc, Hem, Chl, Q, Km, Py M, Ab, Cc, Q, Hem, Chl, Km, Py M, Ab, Cc, Km, Hem, Q Cc, Ab, Q, Km, Hem, Chl

Table 5. Continued do. P do. A do. P do. P do. P do. A do. P do. P do. A Siltstone A do. A do. A do. A do. A do. A do. A do. A Limestone A do. A? do. A? do. A? Siltstone A Quartz monzonite A do. A Pegmatite P do. P do. P Quartz monzonite A Limestone/marble P do. P s Is Iss w Is

ws Iww PI (14),Mf(7),Mt(2) Pl,Mf Pl,Mf PI, PI PI, PI, PI PI, F, F, Mf (20),Mf(3) Mf Mf (16),Mf(7) Mf Q,Cc Q,Cc Dol,Q Cc,Q Cc,Q,F Cc, Q, Vv Q, Q, F, Cbn F, Cbn ,Q Cc, Dol Q, Q, Q, Q, Q, Q, Q, F, Cbn F,Mf F,Mf F, Km, Brl F, Km, Brl F F,Mf M, Ab, Cc, Hem, Q, Chl, Km Km, Q, Py, Cc M, Q, Cc, Py, Km M, Ab, Q, Cc, Hem, Chl M, Q, Ab, Cc, Py, Km M, Q, Py, Cc, Km M, Ab, Hem, Py, Km M, Q, Chl, Km, Hem M, Cc, Py M, Q, Chl, Py Cc,M Km, Py M,Q Cc, M, Ba Cc,M Q,M,Km Q,M,Ep M (vein), Py (vein), Z (vein) Ahy (vein), Py (vein) Py (vein) Py (vein) Q, M, Cc (vein) M, Py, Km M, Cc, Py, Hem, Z Cc, Chl, Ep, Sph, Hem Cc,Ba Cc, M, Chl, Ep, Q, Py M, Cc, Py Py Py,Q

Table 5. Continued. 1,000.6 1,005.6 1,009.5 1,053.1 1,060.7 1,111.5 1,128.6 1,148.0 1,153.9 1,168.0 1,176.2 1,179.4 1,193.6 1,196.2 1,197.2 1,200.4 1,207.3 1,213.9 1,230.3 1,238.5 1,260.2 1,280.2 1,323.5 1,345.8 1,366.1 1,375.0 do. do. do. do. do. P P P P P Skarn P do. P Quartz monzonite A do. A do. P do. do. do. do. do. do. do. do. do. do do. do. do. P P P P P P P P P P P A P do. A do. P Andesite P Quartz monzonite P Quartz vein P W W W Cpx,Q W Vv, Cpx, Ep S Q, F, Mf S Q, F, Mf W Q, Kfo, PI, B, Mt W Q, PI Kfo, B W Q, PI, Kfo W Q, Kfo, PI, B W Q, Kfo, PI, B Chl S Q, Kfo, PI, B W Q, Kfo, PI M Q, Kfo, PI W Q, Kfo, PI W Q, Kfo, PI Q, Kfo, PI W Q, Kfo, PI, B partially replaced by deuteric Chl S Q, Kfo, PI, Km W Q, Kfo, PI, B partially replaced by deuteric Chl, Km M-S Q, Kfo, PI, Km W Q, Kfo, PI W-M Q, Kfo, PI S Q, Kfo, PI W Q, Kfo, PI M,Cc Py Q, Cc, Py, Cor Py Q, Cc, Py, Hem Cc, Py Cc (vein) M, Py, Km M, Q, Py Km, M, Hem M, Km, Py, Sph M, Cc, Py M, Km, Py M, Py, Km M, Km, Py M, Cc (vein), Py (vein), Hem (vein) M, Py, Hem M, Chl, Cc, Py M, Py Q, Py, Km M,Cc M, Py M, Km, Py, Cc M, Km, Py M, Py M, Chl, Cc, Py, Sph M, Q, Dia, Py, Sph M, Py, G, Sph

Table 5. Continued. 1,393.4 Quartz monzonite P 1,404.8 do. P 1,417.6 do. P 1,420.6 do. P. 1,444.5 do. P, A 1,452.4 do. A 1,476.4 do. A 1,499.0 do. A M M M M S S W M Q, Kfo, PI, B, Chl Q, Kfo, PI, B, Chl Q, Kfo, PI, B, Chl, Mt Q, Kfo, PI, B, Chl, Mt Q, Kfo, PI Q, Kfo, PI Q, Kfo, PI, B, Chl Q, Kfo, PI, B, Km(?) M,Cc M, Cc, Km, Chl, Q, Sph, Hem M,Cc M,Cc M, Q, Py, Sph, Dia, K(?) M,Cc M, Km, Py M, Py, Km, Cc

Table 6. Petrographic data for thin sections taken from Goldfield Drill Hole USGS 2. [Alteration types: P, propylitic; A, argillic. W, weak alteration; most primary minerals remain. M, moderate alteration; groundmass largely to completely altered, and phenocrysts partly altered. S, strong alteration; no primary minerals remain but original textures preserved. I, intense alteration; primary minerals and textures completely obliterated. Mineral species codes are: Ab, albite; Any, anhydrite; B, biotite; Ba, barite; Brl, beryl; Cbn, carbonaceous material; Cc, calcite; Chb, chabazite; Chl, chlorite; Cor, corundum; Cpx, clinopyroxene (diopsite/augite); Dia, diaspore; Dol, dolomite; Ep, epidote; F, feldspar; G, goethite; Hbl, hornblende; Hem, hematite; J, jarosite; K, kaolinite; Kfa, adularia; Kfo, orthoclase; Kfs, sanidirie; Km, potassium mica (includes muscovite); Lm, laumontite; Lx, leucoxene; M, montmorillonite; Mf, mafics, species indeterminant due to alteration; Mt, magnetite; Opx, orthopyroxene; PI, plagioclase; Py, pyrite; Q, quartz; Sph, sphene; Vv, vesuvianite; Z, zeoh'te. Numbers in parentheses () are visual estimates of modal percentages and refer to phenocrysts only; tr, trace] Depth ft m Rock type Andesite do. do. do. do. do. do. do. do. do. do. do. do. do. do. do. do. do. do. do. Alteration type P P P P A P P A A A A A A,P P P,A P,A A A P P Degree of alteration S S S S M S-I S-I S S S M S Primary minerals (in order of decreasing abundance) Pl(15),Mf(2),Mt(l) Pl(25),Mf(3),Mt(l) Pl(15),Mf(3),Mt(l) Pl(20),Mf(2),Mt(l) Pl(25),Mf(7),Mt(l) PI (10?), Mf Pl,Mf PI, Mf PI, Mf PI, Mf, Mt Pl(20),Mf(2?) PI, Mf Pl(20),Mf(5) Pl(20),Mf(5) Pl(25),Mf(5) Pl(25),Mf(4) PI, Mf Pl,Mf PI (15), Mf (10) Pl(15),Mf(5) Secondary minerals (in order of decreasing abundance) Chl, Ab, Cc, Q, Z, Kfa, Ep, Hem, Sph Ab, Chl, Cc, Z, M, Ep, Kfa, Sph, Hem Ab, K, Chl, Cc, Q, Kfa, Chb, Ep, Sph Ab, Chl, K, Cc, Ep, Lm, Sph, Hem K, M, Cc, Lx, Q, Py, Hem M, Ab, Q, Py, Z (probably Lm), Kfa, Cc, Sph M, Ab, Py, Q, Cc, Ep, Sph M, Py, Lx, Cc M, Ab, Chl, Py, Cc, Ep, Sph M, Ab, Cc, Py, Sph M, Ab, Py, Q M, Ab, Py, Cc Ab, M, Cc, Py, Q, Chl, Ep, Sph Ab, Q, Chl, M, Py, Cc, Lx M, Ab, Cc, Chl, Py, Km Cc, M, K, Py, Chl, Q M, Ab, Cc, Chl, Q, Py, Sph M, Chl, Q, Ab, Cc, Py, Ep, Z M, Cc, Ab, Chl, Q, Py, Sph, Z M, Cc, Chl, Ab, Py, Q, Z, Lx

Table 6. Continued. do. A,P W PI (15), Cpx (6), Opx (1), 1,011.9 1,034.5 1,063.7 1,089.3 1,112.3 1,130.6 1,156.6 1,178.2 1,194.0 1,200.1 1,217.6 1,246.8 1,265.1 1,267.5 1,278.5 1,290.4 1,321.6 1,378.3 1,395.4 1,398.0 1,399.7 1,402.9 1,414.1 1,439.0 do. Andesite tuff Andesite Andesite tuff (?) Andesite do. do. do. do. do. do. do. do. do. Rhyodacite tuff do. Rhyodacite lapilli tuff do. do. Rhyodacite tuff Andesite do. do. Conglomerate Rhyodacite tuff and sandstone Andesite P A P A A A A A P P P A,P A,P P A A A A A A P P P A A P S S S S S S W M M M S S S M S S S S S S S S S PI (15), Mf PI, Q, Mf Pl,Mf PI, Mf Pl(15),Mf(l) Pl(15)[Mf(2) PI, Mf PI, Mf PI (10), Q (3), Mf PI (20), Cpx (5), Hbl (1), Mt (2), Opx (3) Pl(15),Mf(10),Mt(2) Pl(20),Mf(5),Mt(2) Pl(20),Mf(8),Mt(2) Pl(20),Mf(5) F, Q, Mf F,Q,Mf F, Q, Mf F,Q,Mf F, Q, Mf F, Q, Mf PI (15), Mf PI (15), Mf PI (15), Mf F, Q, Mf F, Q, Mf PI (15), Mf Chl, K(?), Cc, Ab, Q, Sph, Py, Z Chl, Cc, Ab, Sph, Py, Q, Z Chl, M, Ab, Q, Py, Lm, Cc, Sph M, Q, Py, Chl, Ab, Z, Cc, Ep, Km M, Ab, Q, Py, Cc, Sph, Ep M, Ab, Q, Cc, Py, Chl, Km, Sph M, Ab, Cc, Py, Q, Km, Sph, Chl M, Ab, Q, Py, Chl, Cc, Km, Sph, Lx M, Ab, Py, Cc, Chl, Q, Sph, Km M, Ab, Cc, Q, Py, Chl, Sph, Km M, Cc, Chl, Sph, Hem M, Cc Ab, Chl, Q, Py, Z, Lm, Ep, Sph M, Chl, Ab, Cc, Hem, Sph, Ep, Z M, Chl, Sph, Cc, Hem, Z, Py Chl, Ab, Cc, Sph, Py, Ep, Q, Hem M, Chl, Q, Ab, Kfa, Cc, Py M, Q, Py, Ab, Cc M, Ab, Cc, Q, Py, Ba Km, Q, Py, M, Cc, Ba Q, Km, Py, Cc, Chl, Ab, Sph Q, Km, Py, Cc, Ab, G Ab, Cc, M(?), Q, Py, Sph M, Cc, Ab, Chl, Q, Py, Sph, K(?), Hem M, Cc, Ab, Chl, Py, Sph, Q Km, Cc, Q, Py, Lx Km, Cc, Q, Py M, Ab, Cc, Chl, Py, Q

Table 7. Petrographic data for thin sections taken from Goldfield Drill Hole USGS 3. [Alteration types: P, propylitic; A, argillic. W, weak alteration; most primary minerals remain. M, moderate alteration; groundmass largely to completely altered, and phenocrysts partly altered. S, strong alteration; no primary minerals remain but original textures preserved. I, intense alteration; primary minerals and textures completely obliterated. Mineral species codes are: Ab, albite; Any, anhydrite; B, biotite; Ba, barite; Brl, beryl; Cbn, carbonaceous material; Cc, calcite; Chb, chabazite; Chl, chlorite; Cor, corundum; Cpx, clinopyroxene (diopsite/augite); Dia, diaspore; Dol, dolomite; Ep, epidote; F, feldspar; G, goethite; Hbl, hornblende; Hem, hematite; J, jarosite; K, kaolinite; Kfa, adularia; Kfo, orthoclase; Kfs, sanidine; Km, potassium mica (includes muscovite); Lm, laumontite; Lx, leucoxene; M, montmorillonite; Mf, mafics, species indeterminant due to alteration; Mt, magnetite; Opx, orthopyroxene; PI, plagioclase; Py, pyrite; Q, quartz; Sph, sphene; Vv, vesuvianite; Z, zeolite. Numbers in parentheses () are visual estimates of modal percentages and refer to phenocrysts only; tr, trace Depth ft m Rock Alteration Degree of type type alteration Primary minerals (in order of decreasing abundance) Secondary minerals (in order of decreasing abundance) Rhyodacite do. P P S-I S PI (20), B (5), Hbl (1), PI (20), B (4), Hbl (1), M, Q, Ab, Cc, Chl, Km, Hem, Sph, Ep M, Q, Ab, Cc, Chl, Km, Hem do. do. do. do. do. do. do. do. do. Conglomerate Latitetuff do. Rhyodacite Latite P P A A,P A,P P A A A,P A A A A,P A,P S S S S S M M Mt(l)Q(tr) PI, B, Mt PI (20), B (4), Hbl (2) Mt (tr) PI, Mf, Q, Mt Pl,Mf,Q,Mt Pl(20),Mf(5),Q,Mt(2) Pl,Mf Pl(25),Mf(5) Pl(20),Mf(3),Q(tr) Pl(20),Mf(5),Q(tr) PI (30), B (5) M, Q, Ab, Cc, Chl, Km, Hem, Sph M, Q, Cc, Ab, Chl, Km M, Q, Km, Ab, Chl, Hem, Sph M, Cc, Q, Ab, Py, Km, Hem, Sph M, Cc, Ab, Q, Py, Hem, Km, Ba M, Ab, Cc, Q, Py, Hem, Km, Chl, Sph M, Q, Py, Km, Sph M, Ab, Py, Q, Km, J M, Q, Ab, Py, Cc, Km, Sph, Hem M, Q, Km, Py, Cc, Lx Km, M, Py, Cc, Ab M, Q, Km, Cc, Py, Lx Ab, Q, Chl, Cc, Py, Km, Lx Ab, Cc, M, Q, Km, Py

GEOCHEMICAL DATA ANALYTICAL METHODS All samples were subjected to six-step semiquantitative emission spectrographic analysis (Grimes and Marranzino, 1968). Elements determined by this method (with lower detection limit in parentheses) include iron (0.05%), magnesium (0.02%), calcium (0.05%), titanium (0.002%), manganese (10 ppm), silver (0.5 ppm), arsenic (200 ppm), gold (10 ppm), boron (10 ppm), barium (20 ppm), beryllium (1 ppm), bismuth (10 ppm), cadmium (20 ppm), cobalt (5 ppm), chromium (5 ppm), copper (5 ppm), lanthanum (20 ppm), molybdenum (5 ppm), niobium (10 ppm), nickel (5 ppm), lead (10 ppm), antimony (100 ppm), scandium (5 ppm), tin (10 ppm), strontium (100 ppm), vanadium (10 ppm), tungsten (50 ppm), yttrium (10 ppm), zinc (200 ppm), and zirconium (10 ppm). Detection limits for arsenic, gold, bismuth, cadmium, antimony, tin, and tungsten are too high to yield useful data for most samples in this data set. Consequently gold was also determined by an atomic absorption method, using a cold hydrobromic acid extraction from 10-gram analytical portions (Thompson and others, 1968), with a reported sensitivity of 0.02 ppm. Arsenic was also determined by the Gutzeit colorimetric method (Ward and others, 1963), with a sensitivity of 10 ppm. Mercury was determined by a vapor atomic absorption method (Vaughn and McCarthy, 1964), with a sensitivity of 0.01 ppm. Supplemental analyses were obtained for selected samples from drill hole USGS 1, including tellurium by an atomic absorption method, and antimony, molybdenum, and zinc by colorimetric methods (Nakagawa and Thompson, 1968; Ward and others, 1963). All samples were analyzed in laboratories of the U.S. Geological Survey, in Denver, Colorado, in 1968 and 1969. RESULTS Drill hole USGS 1 Tables 8 and 9 show analytical data for drill hole USGS 1. Elements listed above that are omitted showed no values above their respective detection thresholds. Figure 2 shows geochemical logs for the most interesting elements, including gold, silver, arsenic, mercury, copper, zinc, lead, bismuth, manganese, chromium, vanadium, barium, iron, magnesium, and calcium, for the entire length of the hole. Figure 3 shows geochemical logs for the 921-1083-ft (280.7-330.1-m) interval sampled in detail. Figure 3 includes plots for gold, tellurium, antimony, arsenic, mercury, copper, zinc, lead, silver, bismuth, molybdenum, tin, boron, beryllium, manganese, chromium, vanadium, barium, iron, magnesium, calcium, titanium and zirconium. Altered zones below 680 ft (207 m) depth in USGS 1 show sporadic low gold values, just above the detection threshold. Otherwise there is little sign of mineralization related to hydrothermal alteration in this drill hole. Copper, chromium, and vanadium are relatively abundant in siltstones of the Palmetto Formation, and anomalous in some fault zones that cut the siltstones. Boron, beryllium, molybdenum, zinc, bismuth, tin, manganese, and barium are relatively

abundant in greisen or skarn, or both, found between 942.5 ft (287.3 m) and 1,069 ft (319.6 m). Detailed sampling and supplementary analyses of the interval from 921 ft to 1083 ft (280.7-330.1 m) show that anomalous amounts of tellurium, antimony, cobalt, and nickel are also associated with skarn, antimony and zirconium are also associated with greisen, and tellurium and antimony are associated with quartz veins that cut marble. Relatively high iron concentrations are generally the result of abundant pyrite rather than differences in original rock type. The andesite dike at 1,341.5- 1,362.4 ft (408.9-415.2 m), however, appears anomalous in iron because it has a higher mafic mineral content than the surrounding quartz monzonite. Magnesium and calcium vary in abundance depending both upon original rock type and intensity of hydrothennal alteration.

Figure 2A. Geochemical logs for gold and silver, drill hole USGS 1. 0.01 0.02

""

Au ppm u rn oU I 200 ofrn ocn 45Q

v/VV

Depth, ft

Ag, ppm

Figure 2A. Continued. 0.01 0.02

Au, ppm Depth, ft r-

)

) ) )

Ag, ppm

Figure 2B. Geochemical logs for arsenic and mercury, drill hole USGS 1. As, ppm Depth, ft Hg, ppm

Figure 2B. Continued. As, ppm

Depth, ft Hg, ppm

Figure 2C. Geochemical logs for copper and zinc, drill hole USGS 1.

) ) ) ) )

) )

Cu, ppm Depth, ft Zn, ppm

Figure 2C. Continued. -'

/- Ns

- - -

f N/

?

,

p '

)u, ppm /DU" oou 9UU Qcn

I 12*50

Depth, ft

Zr

i, ppm

Figure 2D. Geochemical logs for lead and bismuth, drill hole USGS 1. Pb, ppm

( ) ) ) ) ) ) ) )

Depth, ft Bi, ppm

Figure 2D. Continued. ) ) ) ) ) ) ) ) ) )

Pb, ppm Depth, ft Zn, ppm

Figure 2E. Geochemical log for manganese, drill hole USGS 1. Depth, ft Mn, ppm

Figure 2E. Continued. Depth, ft Mn, ppm

Figure 2F. Geochemical logs for chromium and vanadium, drill hole USGS 1. Cr, ppm Depth, ft V.ppm

Figure 2F. Continued.

Cr, ppm Depth, ft V, ppm

Figure 2G. Geochemical log for barium, drill hole USGS 1. 5000 10000

Depth, ft Ba, ppm

Figure 2G. Continued. 5000 10000 Depth, ft Ba, ppm

Figure 2H. Geochemical log for iron, drill hole USGS 1. Depth, ft Fe, percent

Figure 2H. Continued. Depth, ft Fe, percent

Figure 21. Geochemical log for magnesium, drill hole USGS 1. Depth, ft Mg, percent

Figure 21. Continued. Depth, ft Mg, percent

Figure 2J. Geochemical log for calcium, drill hole USGS 1. Depth, ft Ca, percent

Figure 2J. Continued. Depth, ft Ca, percent

Table 8. Chemical data for drill hole USGS 1. Fe, Mg, Ca, and Ti in weight percent, all other elements in parts per million by weight. Au and Hg determined by atomic absorption spectro- photometry; As by a colorimetric method; all other elements by emission spectrometry. N, not detected; L, present, but below detection limit; G, greater than (value shown); M, missing. Sample interval Au As Hg Fe Ca Ti Mn Feet Meters 11.9-14.6 14.6-17.7 17.7-20.9 20.9-21.9 21.9-25.0 25.0-28.0 28.0-31.1 31.1-34.7 34.7-37.8 37.8-40.8 40.8-43.9 43.9-46.9 46.9-50.0 50.0-53.0 53.0-56.1 56.1-59.1 59.1-62.2 62.2-65.2 65.2-68.3 68.3-71.3 71.3-74.3 74.3-77.4 77.4-80.4 80.4-83.5 83.5-86.5 86.5-89.6 89.6-92.6 92.6-95.7 95.7-98.7 98.7-101.8 101.8-104.8 104.8-107.9 107.9-110.9 110.9-114.0 114.0-117.0 117.0-120.1 120.1-123.1 123.1-126.1 126.1-129.2 129.2-132.2 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N p. 63

TableS. Continued. Sample interval Feet Meters 11.9-14.6 14.6-17.7 17.7-20.9 20.9-21.9 21.9-25.0 25.0-28.0 28.0-31.1 31.1-34.7 34.7-37.8 37.8-40.8 40.8-43.9 43.9-46.9 46.9-50.0 50.0-53.0 53.0-56.1 56.1-59.1 59.1-62.2 62.2-65.2 65.2-68.3 68.3-71.3 71.3-74.3 74.3-77.4 77.4-80.4 80.4-83.5 83.5-86.5 86.5-89.6 89.6-92.6 92.6-95.7 95.7-98.7 98.7-101.8 101.8-104.8 104.8-107.9 107.9-110.9 110.9-114.0 114.0-117.0 117.0-120.1 120.1-123.1 123.1-126.1 126.1-129.2 129.2-132.2 Ag N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N B Ba Be N Co N Cr Cu La Mo N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Nb N Ni p. 64

TableS. Continued. Sample interval Pb Sc Sn Sr Zn Zr Other Feet Meters 11.9-14.6 14.6-17.7 17.7-20.9 20.9-21.9 21.9-25.0 25.0-28.0 28.0-31.1 31.1-34.7 34.7-37.8 37.8-40.8 40.8-43.9 43.9-46.9 46.9-50.0 50.0-53.0 53.0-56.1 56.1-59.1 59.1-62.2 62.2-65.2 65.2-68.3 68.3-71.3 71.3-74.3 74.3-77.4 77.4-80.4 80.4-83.5 83.5-86.5 86.5-89.6 89.6-92.6 92.6-95.7 95.7-98.7 98.7-101.8 101.8-104.8 104.8-107.9 107.9-110.9 110.9-114.0 114.0-117.0 117.0-120.1 120.1-123.1 123.1-126.1 126.1-129.2 129.2-132.2 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N p. 65

TableS. Continued. Sample interval Feet Meters 132.2-135.3 135.3-138.3 138.3-141.4 141.4-144.4 144.4-147.5 147.5-150.5 150.5-153.6 153.6-156.6 156.6-159.7 159.7-162.7 162.7-165.8 165.8-168.8 168.8-171.9 171.9-174.9 174.9-177.9 177.9-181.0 181.0-184.0 184.0-187.1 187.1-190.1 190.1-191.0 191.0-194.1 194.1-197.1 197.1-199.6 199.6-202.0 202.0-204.5 204.5-207.5 207.5-210.5 210.5-213.6 213.6-216.6 216.6-219.7 219.7-222.7 222.7-225.8 225.8-228.8 228.8-231.9 231.9-234.9 234.9-238.0 238.0-241.0 242.8-247.7 247.7-250.8 250.8-253.5 255.3-256.9 256.9-259.9 259.9-263.0 Au N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N As(c) N N N N N N N N Hg Fe Mg Ca G20 G20 G20 G20 G20 G20 G20 Ti Mn G5000 G5000 p. 66

TableS. Continued. Sample interval Feet Meters 132.2-135.3 135.3-138.3 138.3-141.4 141.4-144.4 144.4-147.5 147.5-150.5 150.5-153.6 153.6-156.6 156.6-159.7 159.7-162.7 162.7-165.8 165.8-168.8 168.8-171.9 171.9-174.9 174.9-177.9 177.9-181.0 181.0-184.0 184.0-187.1 187.1-190.1 190.1-191.0 191.0-194.1 194.1-197.1 197.1-199.6 199.6-202.0 202.0-204.5 204.5-207.5 207.5-210.5 210.5-213.6 213.6-216.6 216.6-219.7 219.7-222.7 222.7-225.8 225.8-228.8 228.8-231.9 231.9-234.9 234.9-238.0 238.0-241.0 242.8-247.7 247.7-250.8 250.8-253.5 255.3-256.9 256.9-259.9 259.9-263.0 Ag N N N N N N N N N N N N N N N N N N N N N B N N N Ba Be N Co Cr Cu La Mo N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Nb N N N N N N N N N N N N N N N N N N Ni p. 67

TableS. Continued. Sample interval Feet Meters 132.2-135.3 135.3-138.3 138.3-141.4 141.4-144.4 144.4-147.5 147.5-150.5 150.5-153.6 153.6-156.6 156.6-159.7 159.7-162.7 162.7-165.8 165.8-168.8 168.8-171.9 171.9-174.9 174.9-177.9 177.9-181.0 181.0-184.0 184.0-187.1 187.1-190.1 190.1-191.0 191.0-194.1 194.1-197.1 197.1-199.6 199.6-202.0 202.0-204.5 204.5-207.5 207.5-210.5 210.5-213.6 213.6-216.6 216.6-219.7 219.7-222.7 222.7-225.8 225.8-228.8 228.8-231.9 231.9-234.9 234.9-238.0 238.0-241.0 242.8-247.7 247.7-250.8 250.8-253.5 255.3-256.9 256.9-259.9 259.9-263.0 Pb N Sc Sn N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Sr N Y Zn N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Zr Other 70 W=200 p. 68

TableS. Continued. Sample interval Feet 1003-1013 1013-1023 1023-1033 1033-1043 1043-1053 1053-1063 1063-1073 1073-1083 1083-1093 1093-1103 1103-1113 1113-1123 1123-1133 1133-1143 1143-1153 1153-1163 1163-1173 1173-1183 1183-1193 1193-1203 1203-1213 1213-1223 1223-1233 1233-1243 1243-1253 1253-1263 1263-1273 1273-1283 1283-1304 Meters 263.0-266.0 266.0-269.1 269.1-272.1 272.1-275.1 275.1-278.2 278.2-280.6 281.2-284.3 284.3-287.3 287.3-290.4 290.4-293.4 293.4-296.5 296.5-299.5 299.5-302.6 302.6-305.6 305.6-308.7 308.7-311.7 311.7-314.8 314.8-317.8 317.8-320.8 320.8-323.9 323.9-326.9 326.9-330.0 330.0-333.0 333.0-336.1 336.1-339.1 339.1-342.2 342.2-345.2 345.2-348.3 348.3-351.3 351.3-354.4 354.4-357.4 357.4-360.5 360.5-363.5 363.5-366.6 366.6-369.6 369.6-372.6 372.6-375.7 375.7-378.7 378.7-381.8 381.8-384.8 384.8-387.9 387.9-390.9 390.9-397.3 Au N N N N N N N N N As(c) Hg Fe Mg Ca G20 G20 G20 G20 G20 G20 G20 G20 G20 G20 G20 G20 Ti Mn G5000 G5000 G5000 p. 69

TableS. Continued. Sample interval Feet 1003-1013 1013-1023 1023-1033 1033-1043 1043-1053 1053-1063 1063-1073 1073-1083 1083-1093 1093-1103 1103-1113 1113-1123 1123-1133 1133-1143 1143-1153 1153-1163 1163-1173 1173-1183 1183-1193 1193-1203 1203-1213 1213-1223 1223-1233 1233-1243 1243-1253 1253-1263 1263-1273 1273-1283 1283-1304 Meters 263.0-266.0 266.0-269.1 269.1-272.1 272.1-275.1 275.1-278.2 278.2-280.6 281.2-284.3 284.3-287.3 287.3-290.4 290.4-293.4 293.4-296.5 296.5-299.5 299.5-302.6 302.6-305.6 305.6-308.7 308.7-311.7 311.7-314.8 314.8-317.8 317.8-320.8 320.8-323.9 323.9-326.9 326.9-330.0 330.0-333.0 333.0-336.1 336.1-339.1 339.1-342.2 342.2-345.2 345.2-348.3 348.3-351.3 351.3-354.4 354.4-357.4 357.4-360.5 360.5-363.5 363.5-366.6 366.6-369.6 369.6-372.6 372.6-375.7 375.7-378.7 378.7-381.8 381.8-384.8 384.8-387.9 387.9-390.9 390.9-397.3 Ag N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N B N N N N N N N N N N N N N N N N Ba G5000 Be N Co N N N N N N N N N N N N N N N N N N N N N N N N Cr N N N N N N N N N N N N N N N N N N Cu La Mo N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Nb N N N N N N N N N N N N Ni N N N N N N N N N N N p. 70

TableS. Continued. Sample interval Feet 1003-1013 1013-1023 1023-1033 1033-1043 1043-1053 1053-1063 1063-1073 1073-1083 1083-1093 1093-1103 1103-1113 1113-1123 1123-1133 1133-1143 1143-1153 1153-1163 1163-1173 1173-1183 1183-1193 1193-1203 1203-1213 1213-1223 1223-1233 1233-1243 1243-1253 1253-1263 1263-1273 1273-1283 1283-1304 Meters 263.0-266.0 266.0-269.1 269.1-272.1 272.1-275.1 275.1-278.2 278.2-280.6 281.2-284.3 284.3-287.3 287.3-290.4 290.4-293.4 293.4-296.5 296.5-299.5 299.5-302.6 302.6-305.6 305.6-308.7 308.7-311.7 311.7-314.8 314.8-317.8 317.8-320.8 320.8-323.9 323.9-326.9 326.9-330.0 330.0-333.0 333.0-336.1 336.1-339.1 339.1-342.2 342.2-345.2 345.2-348.3 348.3-351.3 351.3-354.4 354.4-357.4 357.4-360.5 360.5-363.5 363.5-366.6 366.6-369.6 369.6-372.6 372.6-375.7 375.7-378.7 378.7-381.8 381.8-384.8 384.8-387.9 387.9-390.9 390.9-397.3 Pb N N N Sc N Sn N N N N N N N N N N N N N N N N N N N N N N Sr N Y Zn N N N N N N N N N N N N N N N N Zr Other Bi=15 Bi=30 Bi=70 Bi=70 p. 71

TableS. Continued. Sample interval Au As(c) Hg Fe Mg Ca Ti Mn Feet 1304-1314 1314-1324 1324-1334 1334-1342 1342-1352 1352-1363 1363-1370 1370-1380 1380-1390 1390-1400 1400-1410 1410-1420 1420-1430 1430-1440 1440-1450 1450-1460 1460-1470 1470-1480 1480-1490 1490-1505 Meters 397.3-400.4 400.4-403.4 403.4-406.5 406.5-408.9 408.9-412.0 412.0-415.3 415.3-417.4 417.4-420.5 420.5-423.5 423.5-426.6 426.6-429.6 429.6-432.7 432.7-435.7 435.7-438.8 438.8-441.8 441.8-444.9 444.9-447.9 447.9-451 .0 451.0-454.0 454.0-458.6 N N N N N N N N N p. 72

Sample interval Ag TableS. Continued. B Ba Be Co Cr Cu La Mo Nb Ni Feet 1304-1314 1314-1324 1324-1334 1334-1342 1342-1352 1352-1363 1363-1370 1370-1380 1380-1390 1390-1400 1400-1410 1410-1420 1420-1430 1430-1440 1440-1450 1450-1460 1460-1470 1470-1480 1480-1490 1490-1505 Meters 397.3-400.4 400.4-403.4 403.4-406.5 406.5-408.9 408.9-412.0 412.0-415.3 415.3-417.4 417.4-420.5 420.5-423.5 423.5-426.6 426.6-429.6 429.6-432.7 432.7-435.7 435.7-438.8 438.8-441.8 441.8-444.9 444.9-447.9 447.9-451.0 451.0-454.0 454.0-458.6 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N p. 73

TableS. Continued. Sample interval Pb Sc Sn Sr Y Zn Zr Other Feet 1304-1314 1314-1324 1324-1334 1334-1342 1342-1352 1352-1363 1363-1370 1370-1380 1380-1390 1390-1400 1400-1410 1410-1420 1420-1430 1430-1440 1440-1450 1450-1460 1460-1470 1470-1480 1480-1490 1490-1505 Meters 397.3-400.4 400.4-403.4 403.4-406.5 406.5-408.9 408.9-412.0 412.0-415.3 415.3-417.4 417.4-420.5 420.5-423.5 423.5-426.6 426.6-429.6 429.6-432.7 432.7-435.7 435.7-438.8 438.8-441.8 441.8-444.9 444.9-447.9 447.9-451.0 451.0-454.0 454.0-458.6 N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N p. 74

Figure 3A. Geochemical logs for gold and tellurium, drill hole USGS 1 detailed sampling. 0.01 0.02 -980100010201040106010801100Au, ppm Depth, ft Te, ppm

Figure 3B. Geochemical logs for antimony and arsenic, drill hole USGS 1 detailed sampling. 1100Sb, ppm Depth, ft As, ppm

Figure 3C. Geochemical log for mercury, drill hole USGS 1 detailed sampling. Depth, ft Hg.ppm

Figure 3D. Geochemical logs for copper and zinc, drill hole USGS 1 detailed sampling. Cu, ppm Depth, ft Zn, ppm

Figure 3£. Geochemical logs for lead and silver, drill hole USGS 1 detailed sampling. 10001020- -1040106010801100Pb, ppm Depth, ft Ag, ppm

Figure 3F. Geochemical log for bismuth, drill hole USGS 1 detailed sampling. Depth, ft Bi, ppm

Figure 3G. Geochemical log for molybdenum, drill hole U3GS 1 detailed sampling. Depth, ft Mo, ppm

Figure 3H. Geochemical log for tin, drill hole USGS 1 detailed sampling. Depth, ft Sn, ppm

Figure 31. Geochemical logs for boron and beryllium, drill hole USGS 1 detailed sampling. B, ppm Depth, ft Be, ppm

Figure 3J. Greochemical log for manganese, drill hole USGS 1 detailed sampling. 5000 10000 Depth, ft Mn, ppm

Figure 3K. Geochemical logs for chromium and vanadium, drill hole USGS 1 detailed sampling. Cr, ppm -98010001020- 10401060- -10801100Depth, ft V.ppm

Figure 3L. Geochemical log for barium, drill hole USGS 1 detailed sampling. 5000 10000 Depth, ft Ba, ppm

Figure 3M. Geochemical log for iron, drill hole USGS 1 detailed sampling. Depth, ft Fe, percent

Figure 3N. Geochemical log for magnesium, drill hole USGS 1 detailed sampling. Depth, ft Mg, percent

Figure 3O. Geochemical log for calcium, drill hole USGS 1 detailed sampling. Depth, ft Ca, percent

Figure 3P. Geochemical log for titanium, drill hole USGS 1 detailed sampling. Depth, ft Ti, percent

Figure 3Q. Geochemical log for zirconium, drill hole USGS 1 detailed sampling. Depth, ft Zr, ppm

Table 9. Chemical data for drill hole USGS 1, detailed sampling. Fe, Mg, Ca, and Ti in weight percent, all other elements in parts per million by weight. Au, Hg, and Te determined by atomic absorption spectrophotometry; As, Mo(c), Sb(c), and Zn(c) by colorimetric methods; all other elements by emission spectrometry. N, not detected; L, present, but below detection limit; G, greater than (value shown); H, interference. Sample interval Feet 626.7-633 655-661.5 661.5-664 731-736.5 736.5-743 813-815.5 831.5-840.5 840.5-842.3 842.3-847.1 847.1-854 926-927.8 927.8-933 933-936.5 936.5-941.5 941.5-942.5 942.5-943.5 943.5-948 960-962.5 962.5-963.7 963.7-970 970-972.5 972.5-975 975-984.8 984.8-989.7 989.7-997.5 997.5-1002 1002-1004.5 1004.5-1008 1008-1010 1010-1020 1020-1030 1030-1037.5 1037.5-1044.5 Meters 191.0-192.9 192.9-194.4 199.6-201.6 201.6-202.3 222.7-224.4 224.4-226.4 227.9-229.7 229.7-231.9 242.8-244.7 246.8-247.7 247.7-248.5 253.4-256.1 256.1-256.6 256.6-258.1 258.1-260.2 274.5-275.8 280.6-282.2 282.2-282.7 282.7-284.3 284.3-285.4 285.4-286.9 286.9-287.2 287.2-287.5 287.5-288.9 288.9-290.7 290.7-292.5 292.5-293.3 293.3-293.6 293.6-295.6 295.6-296.3 296.3-297.1 297.1-300.1 300.1-301.6 301.6-303.9 303.9-305.3 305.3-306.1 306.1-307.1 307.1-307.7 307.7-310.8 310.8-313.8 313.8-316.1 316.1-318.3 Au H0.2 As N N N <10 Hg Mo(c) Sb(c) N N N Te Zn(c) p. 92

Table 9, continued Sample interval Feet 626.7-633 655-661.5 661.5-664 731-736.5 736.5-743 813-815.5 831.5-840.5 840.5-842.3 842.3-847.1 847.1-854 926-927.8 927.8-933 933-936.5 936.5-941.5 941.5-942.5 942.5-943.5 943.5-948 960-962.5 962.5-963.7 963.7-970 970-972.5 972.5-975 975-984.8 984.8-989.7 989.7-997.5 997.5-1002 1002-1004.5 1004.5-1008 1008-1010 1010-1020 1020-1030 1030-1037.5 1037.5-1044.5 Meters 191.0-192.9 192.9-194.4 199.6-201.6 201.6-202.3 222.7-224.4 224.4-226.4 227.9-229.7 229.7-231.9 242.8-244.7 246.8-247.7 247.7-248.5 253.4-256.1 256.1-256.6 256.6-258.1 258.1-260.2 274.5-275.8 280.6-282.2 282.2-282.7 282.7-284.3 284.3-285.4 285.4-286.9 286.9-287.2 287.2-287.5 287.5-288.9 288.9-290.7 290.7-292.5 292.5-293.3 293.3-293.6 293.6-295.6 295.6-296.3 296.3-297.1 297.1-300.1 300.1-301.6 301.6-303.9 303.9-305.3 305.3-306.1 306.1-307.1 307.1-307.7 307.7-310.8 310.8-313.8 313.8-316.1 316.1-318.3 Fe t Mg Ca G20 G20 G20 G20 G20 G20 G20 Ti Mn G5000 G5000 G5000 Ag N N N N N N N N N N N N N N N N N N N N N B N N N N N N N N N N N N Ba G5000 Be N p. 93

Table 9, continued Sample interval Feet 626.7-633 655-661.5 661.5-664 731-736.5 736.5-743 813-815.5 831.5-840.5 840.5-842.3 842.3-847.1 847.1-854 926-927.8 927.8-933 933-936.5 936.5-941.5 941.5-942.5 942.5-943.5 943.5-948 960-962.5 962.5-963.7 963.7-970 970-972.5 972.5-975 975-984.8 984.8-989.7 989.7-997.5 997.5-1002 1002-1004.5 1004.5-1008 1008-1010 1010-1020 1020-1030 1030-1037.5 1037.5-1044.5 Meters 191.0-192.9 192.9-194.4 199.6-201.6 201.6-202.3 222.7-224.4 224.4-226.4 227.9-229.7 229.7-231.9 242.8-244.7 246.8-247.7 247.7-248.5 253.4-256.1 256.1-256.6 256.6-258.1 258.1-260.2 274.5-275.8 280.6-282.2 282.2-282.7 282.7-284.3 284.3-285.4 285.4-286.9 286.9-287.2 287.2-287.5 287.5-288.9 288.9-290.7 290.7-292.5 292.5-293.3 293.3-293.6 293.6-295.6 295.6-296.3 296.3-297.1 297.1-300.1 300.1-301.6 301.6-303.9 303.9-305.3 305.3-306.1 306.1-307.1 307.1-307.7 307.7-310.8 310.8-313.8 313.8-316.1 316.1-318.3 Bi N N N N N N N N N N N N N N N N N N N N N N N N N N N N Co N N N N N N N N N N N N N N N N N N N N N N Cr N N N N N N N N N N N N N N N N N Cu N La N N N N N N N N N N N N N N N N N Mo N N N N N N N N N N N N N N N G2000 N N N N N Nb N N N N N N N N N N Ni Pb N N N N N N p. 94

Table 9, continued Sample interval Feet 626.7-633 655-661.5 661.5-664 731-736.5 736.5-743 813-815.5 831.5-840.5 840.5-842.3 842.3-847.1 847.1-854 926-927.8 927.8-933 933-936.5 936.5-941.5 941.5-942.5 942.5-943.5 943.5-948 960-962.5 962.5-963.7 963.7-970 970-972.5 972.5-975 975-984.8 984.8-989.7 989.7-997.5 997.5-1002 1002-1004.5 1004.5-1008 1008-1010 1010-1020 1020-1030 1030-1037.5 1037.5-1044.5 Meters 191.0-192.9 192.9-194.4 199.6-201.6 201.6-202.3 222.7-224.4 224.4-226.4 227.9-229.7 229.7-231.9 242.8-244.7 246.8-247.7 247.7-248.5 253.4-256.1 256.1-256.6 256.6-258.1 258.1-260.2 274.5-275.8 280.6-282 282.2-282 282.7-284 284.3-285 285.4-286 286.9-287 287.2-287 287.5-288 288.9-290 290.7-292 292.5-293 293.3-293 293.6-295 295.6-296 296.3-297 297.1-300 300.1-301 301.6-303 303.9-305 305.3-306 306.1-307 307.1-307 307.7-310 310.8-313 313.8-316 316.1-318 Sc N N N N N N N N N N N N N Sn N N N N N N N N N N N N N N N Sr N N N N N N N N N N N N N N N N N N N N Y N Zn N N N N N N N N N N N N N N N N N N N N Zr Other Cd=200 Cd=50 W=G10000 Sb=100 p. 95

Table 9, continued Sample interval Feet 1044.5-1048.5 1048.5-1050.5 1050.5-1053.5 1053.5-1057 1057-1060 1060-1063 1063-1066 1066-1067.8 1067.8-1069 1069-1070 1070-1070.8 1070.8-1077 1077-1083 Meters 318.3-319.5 319.5-320.1 320.1-321.0 321.0-322.1 322.1-323.0 323.0-323.9 323.9-324.8 324.8-325.4 325.4-325.7 325.7-326.0 326.0-326.3 326.3-328.2 328.2-330.0 Au As(c) N Hg Mo(c) Sb(c) N Te Zn(c) p. 96

Table 9, continued Sample interval Feet 1044.5-1048. 1048.5-1050. 1050.5-1053. 1053.5-1057 1057-1060 1060-1063 1063-1066 1066-1067.8 1067.8-1069 1069-1070 1070-1070.8 1070.8-1077 1077-1083 ,5 Meters 318.3-319.5 319.5-320.1 320.1-321.0 321.0-322.1 322.1-323.0 323.0-323.9 323.9-324.8 324.8-325.4 325.4-325.7 325.7-326.0 326.0-326.3 326.3-328.2 328.2-330.0 Fe Mg Ca G20 Ti Mn G5000 Ag N N N N N N N N N B Ba G5000 G5000 G5000 Be p. 97

Table 9, continued Sample interval Feet 1044.5-1048.5 1048.5-1050.5 1050.5-1053.5 1053.5-1057 1057-1060 1060-1063 1063-1066 1066-1067.8 1067.8-1069 1069-1070 1070-1070.8 1070.8-1077 1077-1083 Meters 318.3-319.5 319.5-320.1 320.1-321.0 321.0-322.1 322.1-323.0 323.0-323.9 323.9-324.8 324.8-325.4 325.4-325.7 325.7-326.0 326.0-326.3 326.3-328.2 328.2-330.0 Bi G1000 N N Co N N N Cr N N N Cu N N La N N Mo N N N N Nb Ni Pb N N N N N p. 98

Table 9, continued Sample interval Feet 1044.5-1048.5 1048.5-1050.5 1050.5-1053.5 1053.5-1057 1057-1060 1060-1063 1063-1066 1066-1067.8 1067.8-1069 1069-1070 1070-1070.8 1070.8-1077 1077-1083 Meters 318.3-319 319.5-320 320.1-321 321.0-322 322.1-323 323.0-323 323.9-324 324.8-325 325.4-325 325.7-326 326.0-326 326.3-328 328.2-330 Sc N N N Sn N N N Sr N N N N N N N Y Zn N N N Zr Other W=50 W=50 p. 99

Drill hole USGS 2 Low gold values, accompanied by anomalous amounts of arsenic, mercury, and molybdenum, characterize the tuffs and volcaniclastic sedimentary rocks that dominate the section from a depth of 1,265 ft (385.6 m) nearly to the bottom of the hole at 1,437 ft (438.0 m). As a result of hydrothermal alteration, these rocks are pervasively argillized. Base metals other than molybdenum show no variations that are clearly systematically related to hydrothermal alteration. Iron, magnesium, calcium, and manganese are not significantly depleted in most rocks, and generally reflect abundances in the original rocks, in spite of the fact that much of the core from this drill hole shows strong to intense propylitic or argillic alteration. In the propylitized rocks, these elements are retained in chlorite, pyrite, calcite, zeolites, epidote, and in some cases montmorillonite. The argillic rocks in this drill hole are characterized by an alteration assemblage dominated by montmorillonite. Calcite is common, chlorite persists in many argillic rocks, and clays other than montmorillonite are scarce. Thus hydrothermal alteration produced minimal cation leaching of argillic rocks, and iron, magnesium, calcium, and manganese are retained in pyrite, montmorillonite, calcite, and often chlorite. Figure 4 shows geochemical logs for gold, arsenic, mercury, copper, molybdenum, lead, barium, strontium, magnesium, iron, manganese, and calcium, for the entire length of drill hole USGS 2. Table 10 shows analytical data for this drill hole, omitting elements with no values above their respective detection thresholds.

Figure 4A. Geochemical logs for gold and arsenic, drill hole USGS 2. 0.01 0.02 t

Au, ppm Cft 1 V/V -200" .,- OCA . ouu QCft OOU CAA *Kft CCA

Depth, ft As, ppm

Figure 4A. Continued. 0.01 0.02 Au, ppm Depth, ft As, ppm

Figure 4B. Greochemical log for mercury, drill hole USGS 2. Depth, ft Hg.ppm

Figure 4B. Continued. Depth, ft Hg, ppm

Figure 4C. Geochemical logs for copper and molybdenum, drill hole USGS 2.

) ) ) ) ) ) ) ) ) ) k '

;, Cu, ppm Depth, ft Mo, ppm

Figure 40. Continued. ,

k ;U f Cu, ppm Depth, ft Mo, ppm

Figure 4D. Geochemical log for lead, drill hole USGS 2. /W

11A ion f CA Depth, ft

" Pb.pp

p" s i

m

Figure 4D. Continued. Depth, ft Pb, ppm

Figure 4E. Geochemical logs for barium and strontium, drill hole USGS 2. 5000 10000

Ba, ppm

Depth, ft 5000 10000 Sr, ppm

Figure 4E. Continued. 5000 10000

Ba, ppm Depth, ft 5000 10000 Sr, ppm

Figure 4F. Continued. Mg, percent Depth, ft Fe, percent

Figure 4F. Geochemical logs for magnesium and iron, drill hole USGS 2.

J r u /v ccn

s z /uu Mg, percent Depth, ft Fe, percent

Figure 4G. Geochemical logs for manganese and calcium, drill hole USGS 2. Mn, ppm Depth, ft Ca, percent

Table 10. Chemical data for drill hole USGS 2. Fe, Mg, Ca, and Ti in weight percent, all other elements in parts per million by weight. Au and Hg determined by atomic absorption spectro- photometry; As by a colorimetric method; all other elements by emission spectrometry. N, not detected; L, present, but below detection limit; G, greater than (value shown); M, missing. Sample interval Feet 125-133.5 133.5-137 140-147.5 147.5-154 Meters 12.2-15.2 15.2-18.3 18.3-21.3 21.3-24.4 24.4-27.4 27.4-30.5 30.5-33.5 33.5-36.3 36.3-38.1 38.1-40.7 40.7-41.7 41.7-42.7 42.7-44.9 44.9-46.9 46.9-48.8 48.8-51.8 51.8-54.8 54.8-57.9 57.9-60.9 60.9-64.0 64.0-67.0 67.0-70.1 70.1-73.1 73.1-76.2 76.2-79.2 79.2-82.3 82.3-85.3 85.3-88.4 88.4-90.2 90.2-93.2 93.2-96.3 96.3-99.3 99.3-102.4 102.4-105.4 105.4-108.5 108.5-111.2 111.2-114.3 114.3-117.3 117.3-120.4 120.4-123.4 Au As N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Hg Fe Mg Ca Ti G1 Mn p. 115

Figure 4G. Continued. Mn, ppm Depth, ft Ca, percent

Table 10, continued. Sample interval Feet 125-133.5 133.5-137 140-147.5 147.5-154 Meters 12.2-15.2 15.2-18.3 18.3-21.3 21.3-24.4 24.4-27.4 27.4-30.5 30.5-33.5 33.5-36.3 36.3-38.1 38.1-40.7 40.7-41.7 41.7-42.7 42.7-44.9 44.9-46.9 46.9-48.8 48.8-51.8 51.8-54.8 54.8-57.9 57.9-60.9 60.9-64.0 64.0-67.0 67.0-70.1 70.1-73.1 73.1-76.2 76.2-79.2 79.2-82.3 82.3-85.3 85.3-88.4 88.4-90.2 90.2-93.2 93.2-96.3 96.3-99.3 99.3-102.4 102.4-105.4 105.4-108.5 108.5-111.2 111.2-114.3 114.3-117.3 117.3-120.4 120.4-123.4 Ag N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N B Ba Be Co Cr Cu La Mo Nb Ni p. 116

Table 10, continued. Sample interval Feet 125-133.5 133.5-137 140-147.5 147.5-154 Pb Sc Sr Zr Meters 12.2-15.2 15.2-18.3 18.3-21.3 21.3-24.4 24.4-27.4 27.4-30.5 30.5-33.5 33.5-36.3 36.3-38.1 38.1-40.7 40.7-41.7 41.7-42.7 42.7-44.9 44.9-46.9 46.9-48.8 48.8-51.8 51.8-54.8 54.8-57.9 57.9-60.9 60.9-64.0 64.0-67.0 67.0-70.1 70.1-73.1 73.1-76.2 76.2-79.2 79.2-82.3 82.3-85.3 85.3-88.4 88.4-90.2 90.2-93.2 93.2-96.3 96.3-99.3 99.3-102.4 102.4-105.4 105.4-108.5 108.5-111.2 111.2-114.3 114.3-117.3 117.3-120.4 120.4-123.4 G5000 p. 117

Table 10, continued. Sample interval Feet 471-478.5 478.5-488 508-510.7 510.7-512 512-516.5 516.5-519 548-553.5 553.5-556.5 556.5-566 566-568.5 568.5-572.5 572.5-582 582-590.5 590.5-595.5 595.5-598 Meters 123.4-126.5 126.5-129.5 129.5-132.2 132.2-134.1 134.1-137.1 137.1-138.9 138.9-141.1 141.1-143.5 143.5-145.8 145.8-148.7 148.7-151.4 151.4-152.0 152.0-153.9 153.9-154.2 154.2-154.5 154.5-154.8 154.8-155.6 155.6-156.0 156.0-157.4 157.4-158.1 158.1-160.3 160.3-162.4 162.4-165.5 165.5-167.0 167.0-168.7 168.7-169.6 169.6-172.5 172.5-173.2 173.2-174.4 174.4-177.3 177.3-179.9 179.9-181.4 181.4-182.2 182.2-183.7 183.7-185.3 185.3-186.8 186.8-188.6 188.6-190.4 190.4-192.3 192.3-195.0 195.0-197.4 197.4-199.9 199.9-200.8 Au As(c) N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Hg Fe Mg Ca Ti Mn p. 118

Table 10, continued. Sample interval Feet 471-478.5 478.5-488 508-510.7 510.7-512 512-516.5 516.5-519 548-553.5 553.5-556.5 556.5-566 566-568.5 568.5-572.5 572.5-582 582-590.5 590.5-595.5 595.5-598 Meters 123.4-126.5 126.5-129.5 129.5-132.2 132.2-134.1 134.1-137.1 137.1-138.9 138.9-141.1 141.1-143.5 143.5-145.8 145.8-148.7 148.7-151.4 151.4-152.0 152.0-153.9 153.9-154.2 154.2-154.5 154.5-154.8 154.8-155.6 155.6-156.0 156.0-157.4 157.4-158.1 158.1-160.3 160.3-162.4 162.4-165.5 165.5-167.0 167.0-168.7 168.7-169.6 169.6-172.5 172.5-173.2 173.2-174.4 174.4-177.3 177.3-179.9 179.9-181.4 181.4-182.2 182.2-183.7 183.7-185.3 185.3-186.8 186.8-188.6 188.6-190.4 190.4-192.3 192.3-195.0 195.0-197.4 197.4-199.9 199.9-200.8 Ag N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N B Ba Be Co Cr Cu la Mo Nb Ni p. 119

Table 10, continued. Sample interval Feet 471-478.5 478.5-488 508-510.7 510.7-512 512-516.5 516.5-519 548-553.5 553.5-556.5 556.5-566 566-568.5 568.5-572.5 572.5-582 582-590.5 590.5-595.5 595.5-598 Pb Sc Sr Zr Meters 123.4-126.5 126.5-129.5 129.5-132.2 132.2-134.1 134.1-137.1 137.1-138.9 138.9-141.1 141.1-143.5 143.5-145.8 145.8-148.7 148.7-151.4 151.4-152.0 152.0-153.9 153.9-154.2 154.2-154.5 154.5-154.8 154.8-155.6 155.6-156.0 156.0-157.4 157.4-158.1 158.1-160.3 160.3-162.4 162.4-165.5 165.5-167.0 167.0-168.7 168.7-169.6 169.6-172.5 172.5-173.2 173.2-174.4 174.4-177.3 177.3-179.9 179.9-181.4 181.4-182.2 182.2-183.7 183.7-185.3 185.3-186.8 186.8-188.6 188.6-190.4 190.4-192.3 192.3-195.0 195.0-197.4 197.4-199.9 199.9-200.8 M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M p. 120

Table 10, continued. Sample interval Feet 659-660.5 660.5-664 738-739.5 739.5-741.5 741.5-748 796-807.5 807.5-815 860-861.5 861.5-870 953-955.3 955.3-962 962-968.5 968.5-971.5 971.5-979 Meters 200.8-201.3 201.3-202.3 202.3-205.7 205.7-208.7 208.7-211.8 211.8-214.8 214.8-217.9 217.9-220.3 220.3-222.7 222.7-224.9 224.9-225.3 225.3-225.9 225.9-227.9 227.9-229.7 229.7-231.9 231.9-234.0 234.0-237.4 237.4-240.4 240.4-242.5 242.5-246.0 246.0-248.3 248.3-250.8 250.8-253.5 253.5-254.7 254.7-257.5 257.5-259.9 259.9-262.0 262.0-262.5 262.5-265.1 265.1-267.2 267.2-270.0 270.0-273.9 273.9-277.0 277.0-280.0 280.0-283.1 283.1-286.1 286.1-288.9 288.9-290.4 290.4-291.1 291.1-293.1 293.1-295.1 295,1-296.0 296.0-298.3 Au As(c) N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Hg Fe Mg Ca Ti Mn p. 121

Table 10, continued. Sample interval Feet 659-660.5 660.5-664 738-739.5 739.5-741.5 741.5-748 796-807.5 807.5-815 860-861.5 861.5-870 953-955.3 955.3-962 962-968.5 968.5-971.5 971.5-979 Meters 200.8-201.3 201.3-202.3 202.3-205.7 205.7-208.7 208.7-211.8 211.8-214.8 214.8-217.9 217.9-220.3 220.3-222.7 222.7-224.9 224.9-225.3 225.3-225.9 225.9-227.9 227.9-229.7 229.7-231.9 231.9-234.0 234.0-237.4 237.4-240.4 240.4-242.5 242.5-246.0 246.0-248.3 248.3-250.8 250.8-253.5 253.5-254.7 254.7-257.5 257.5-259.9 259.9-262.0 262.0-262.5 262.5-265.1 265.1-267.2 267.2-270.0 270.0-273.9 273.9-277.0 277.0-280.0 280.0-283.1 283.1-286.1 286.1-288.9 288.9-290.4 290.4-291.1 291.1-293.1 293.1-295.1 295.1-296.0 296.0-298.3 Ag N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N B Ba G5000 Be Co Cr Cu La Mo Nb Ni p. 122

Table 10, continued. Sample interval Feet 659-660.5 660.5-664 738-739.5 739.5-741.5 741.5-748 796-807.5 807.5-815 860-861.5 861.5-870 953-955.3 955.3-962 962-968.5 968.5-971.5 971.5-979 Pb Sc Sr Zr Meters 200.8-201.3 201.3-202.3 202.3-205.7 205.7-208.7 208.7-211.8 211.8-214.8 214.8-217.9 217.9-220.3 220.3-222.7 222.7-224.9 224.9-225.3 225.3-225.9 225.9-227.9 227.9-229.7 229.7-231.9 231.9-234.0 234.0-237.4 237.4-240.4 240.4-242.5 242.5-246.0 246.0-248.3 248.3-250.8 250.8-253.5 253.5-254.7 254.7-257.5 257.5-259.9 259.9-262.0 262.0-262.5 262.5-265.1 265.1-267.2 267.2-270.0 270.0-273.9 273.9-277.0 277.0-280.0 280.0-283.1 283.1-286.1 286.1-288.9 288.9-290.4 290.4-291.1 291.1-293.1 293.1-295.1 295.1-296.0 296.0-298.3 p. 123

Table 10, continued. Sample interval Feet 999-1006.5 1006.5-1016 1016-1026 1026-1036 1036-1045 1045-1055.5 1055.5-1062 1062-1072 1072-1082 1082-1092 1092-1100 1100-1108 1108-1116 1116-1124 1124-1134.5 1134.5-1144.5 1144.5-1146 1146-1150 1150-1158 1164-1173 1173-1181.5 1181.5-1189 1189-1196 1196-1205.5 1205.5-1209.5 1209.5-1216 1216-1223 1223-1233 1233-1241 1241-1250 1250-1259 1259-1262 1262-1265 1265-1270 1270-1276 1276-1279.5 1279.5-1290 1290-1300 1300-1310 1310-1320 1320-1330 Meters 298.3-301.3 301.3-304.4 304.4-306.7 306.7-309.6 309.6-312.6 312.6-315.7 315.7-318.4 318.4-321.6 321.6-323.6 323.6-326.6 326.6-329.7 329.7-332.7 332.7-335.2 335.2-337.6 337.6-340.0 340.0-342.5 342.5-345.7 345.7-348.7 348.7-349.2 349.2-350.4 350.4-352.8 354.7-357.4 357.4-360.0 360.0-362.3 362.3-364.4 364.4-367.3 367.3-368.5 368.5-370.5 370.5-372.6 372.6-375.7 375.7-378.1 378.1-380.9 380.9-383.6 383.6-384.5 384.5-385.4 385.4-387.0 387.0-388.7 388.8-389.9 389.9-393.1 393.1-396.1 396.1-399.2 399.2-402.2 402.2-405.3 Au As(c) N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Hg Fe Mg Ca Ti Mn p. 124

Table 10, continued. Sample interval Feet 999-1006.5 1006.5-1016 1016-1026 1026-1036 1036-1045 1045-1055.5 1055.5-1062 1062-1072 1072-1082 1082-1092 1092-1100 1100-1108 1108-1116 1116-1124 1124-1134.5 1134.5-1144.5 1144.5-1146 1146-1150 1150-1158 1164-1173 1173-1181.5 1181.5-1189 1189-1196 1196-1205.5 1205.5-1209.5 1209.5-1216 1216-1223 1223-1233 1233-1241 1241-1250 1250-1259 1259-1262 1262-1265 1265-1270 1270-1276 1276-1279.5 1279.5-1290 1290-1300 1300-1310 1310-1320 1320-1330 Meters 298.3-301.3 301.3-304.4 304.4-306.7 306.7-309.6 309.6-312.6 312.6-315.7 315.7-318.4 318.4-321.6 321.6-323.6 323.6-326.6 326.6-329.7 329.7-332.7 332.7-335.2 335.2-337.6 337.6-340.0 340.0-342.5 342.5-345.7 345.7-348.7 348.7-349.2 349.2-350.4 350.4-352.8 354.7-357.4 357.4-360.0 360.0-362.3 362.3-364.4 364.4-367.3 367.3-368.5 368.5-370.5 370.5-372.6 372.6-375.7 375.7-378.1 378.1-380.9 380.9-383.6 383.6-384.5 384.5-385.4 385.4-387.0 387.0-388.7 388.8-389.9 389.9-393.1 393.1-396.1 396.1-399.2 399.2-402.2 402.2-405.3 Ag N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N B Ba Be Co Cr Cu La Mo Nb Ni p. 125

Table 10, continued. Sample interval Feet 999-1006.5 1006.5-1016 1016-1026 1026-1036 1036-1045 1045-1055.5 1055.5-1062 1062-1072 1072-1082 1082-1092 1092-1100 1100-1108 1108-1116 1116-1124 1124-1134.5 1134.5-1144.5 1144.5-1146 1146-1150 1150-1158 1164-1173 1173-1181.5 1181.5-1189 1189-1196 1196-1205.5 1205.5-1209.5 1209.5-1216 1216-1223 1223-1233 1233-1241 1241-1250 1250-1259 1259-1262 1262-1265 1265-1270 1270-1276 1276-1279.5 1279.5-1290 1290-1300 1300-1310 1310-1320 1320-1330 Meters 298.3-301.3 301.3-304.4 304.4-306.7 306.7-309.6 309.6-312.6 312.6-315.7 315.7-318.4 318.4-321.6 321.6-323.6 323.6-326.6 326.6-329.7 329.7-332.7 332.7-335.2 335.2-337.6 337.6-340.0 340.0-342.5 342.5-345.7 345.7-348.7 348.7-349.2 349.2-350.4 350.4-352.8 354.7-357.4 357.4-360.0 360.0-362.3 362.3-364.4 364.4-367.3 367.3-368.5 368.5-370.5 370.5-372.6 372.6-375.7 375.7-378.1 378.1-380.9 380.9-383.6 383.6-384.5 384.5-385.4 385.4-387.0 387.0-388.7 388.8-389.9 389.9-393.1 393.1-396.1 396.1-399.2 399.2-402.2 402.2-405.3 Pb Sc Sr Y Zr p. 126

Table 10, continued. Sample interval Au As(c) Hg Fe Mg Ca Ti Mn Feet 1330-1337.5 1337.5-1347 1347-1357 1357-1367 1367-1376 1376-1386 1386-1395 1396.1-1397 1397-1399.5 1400-1400.5 1400.5-1410 1410-1420 1420-1430 1430-1437 1437-1439 Meters 405.3-407.5 407.5-410.4 410.4-413.5 413.5-416.5 416.5-419.3 419.3-422.3 422.3-425.1 425.4-425.7 425.7-426.4 426.6-426.7 426.7-429.6 429.6-432.7 432.7-435.7 435.7-437.9 437.9-438.5 p. 127

Table 10, continued. Sample interval Feet 1330-1337.5 1337.5-1347 1347-1357 1357-1367 1367-1376 1376-1386 1386-1395 1396.1-1397 1397-1399.5 1400-1400.5 1400.5-1410 1410-1420 1420-1430 1430-1437 1437-1439 Meters 405.3-407.5 407.5-410.4 410.4-413.5 413.5-416.5 416.5-419.3 419.3-422.3 422.3-425.1 425.4-425.7 425.7-426.4 426.6-426.7 426.7-429.6 429.6-432.7 432.7-435.7 435.7-437.9 437.9-438.5 Ag N N N N N N N N N N N N B Ba G5000 ? ? ? Be Co Cr Cu La Mo Nb Ni p. 128

Table 10, continued. Sample interval Pb Sc Sr Y Zr Feet Meters 1330-1337.5 405.3-407.5 1337.5-1347 407.5-410.4 1347-1357 410.4-413.5 1357-1367 413.5-416.5 1367-1376 416.5-419.3 1376-1386 419.3-422.3 1386-1395 422.3-425.1 1396.1-1397 425.4-425.7 1397-1399.5 425.7-426.4 1400-1400.5 426.6-426.7 1400.5-1410 426.7-429.6 1410-1420 429.6-432.7 1420-1430 432.7-435.7 1430-1437 435.7-437.9 1437-1439 437.9-438.5 p. 129

Drill hole USGS 3 The rocks from a depth of 326 ft (99.4 m) to the bottom of the hole at 457 ft (139.3 m) show sporadic anomalous amounts of gold, arsenic, mercury, molybdenum, and lead. The rocks in this part of the drill hole are dominantly argillized, whereas the rocks above 326 ft are dominantly propylitized, so these anomalies result from hydrothermal alteration. Although mineral assemblages are generally similar throughout the drill hole, calcium, magnesium, and manganese locally show depletion below 326 ft, suggesting that hydrothermal fluids that affected these rocks were somewhat more acid, and consequently alteration was more intense. Figure 5 shows geochemical logs for drill hole USGS 3, for the same group of elements as shown in figure 4 for drill hole USGS 2, and table 11 shows analytical data for this drill hole, again omitting elements with no values above their respective detection thresholds.

Figure 5A. Greochemical logs for gold and arsenic, drill hole USGS 3. 0.01 0.02

-:

r

t t t

t

Au, ppm Depth, ft As, ppm

Figure 5B. Geochemical log for mercury, drill hole USGS 3. Depth, ft Hg, ppm

Figure 5C. Geochemical logs for copper and molybdenum, drill hole USGS 3. "

t t

) ) ) ) ) )

" Cu, ppm Depth, ft Mo, ppm

Figure 5D. Geochemical log for lead, drill hole USGS 3. Depth, ft Pb, ppm

Figure 5E. Geochemical logs for barium and strontium, drill hole USGS 3.

Ba, ppm Depth, ft Sr, ppm

Figure 5F. Geochemical logs for magnesium and iron, drill hole USGS 3.

-"

SO vA/ &v/V ocn 40

$ Mg, percent Depth, ft Fe, percent

Figure 5G. Greochemical logs for manganese and calcium, drill hole USGS 3. o50 Mn, ppm Depth, ft Ca, percent

Table 11. Chemical data for drill hole USGS 3. Fe, Mg, Ca, and Ti in weight percent, all other elements in parts per million by weight. Au and Hg determined by atomic absorption spectrophotometry; As by a colorimetric method; all other elements by emission spectrometry. N, not detected; L, present, but below detection limit. Sample interval Feet 117-120.5 120.5-129 148-156.5 156.5-164 214-220.5 220.5-229 239-243.8 243.8-249.5 249.5-258.4 258.4-267 274-285.5 285.5-289 289-297.5 297.5-307 365-373.5 Meters 10.1-13.1 13.1-16.1 16.1-19.2 19.2-22.2 22.2-25.3 25.3-28.8 28.8-32.0 32.0-33.5 33.5-35.6 35.6-36.7 36.7-39.3 39.3-42.4 42.4-45.1 45.1-47.7 47.7-50.0 50.0-52.4 52.4-55.8 55.8-59.1 59.1-62.2 62.2-65.2 65.2-67.2 67.2-69.8 69.8-72.8 72.8-74.3 74.3-76.0 76.0-78.7 78.7-81.4 81.4-83.5 83.5-87.0 87.0-88.1 88.1-90.6 90.6-93.5 93.5-96.6 96.6-99.3 99.3-102.4 102.4-105.4 105.4-106.9 106.9-109.7 109.7-111.2 111.2-113.8 Au As N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N Hg Fe Mg Ca Ti Mn B Ba Co p. 138

Table 11. Continued. Sample interval Feet 117-120.5 120.5-129 148-156.5 156.5-164 214-220.5 220.5-229 239-243.8 243.8-249.5 249.5-258.4 258.4-267 274-285.5 285.5-289 289-297.5 297.5-307 365-373.5 Meters 10.1-13.1 13.1-16.1 16.1-19.2 19.2-22.2 22.2-25.3 25.3-28.8 28.8-32.0 32.0-33.5 33.5-35.6 35.6-36.7 36.7-39.3 39.3-42.4 42.4-45.1 45.1-47.7 47.7-50.0 50.0-52.4 52.4-55.8 55.8-59.1 59.1-62.2 62.2-65.2 65.2-67.2 67.2-69.8 69.8-72.8 72.8-74.3 74.3-76.0 76.0-78.7 78.7-81.4 81.4-83.5 83.5-87.0 87.0-88.1 88.1-90.6 90.6-93.5 93.5-96.6 96.6-99.3 99.3-102.4 102.4-105.4 105.4-106.9 106.9-109.7 109.7-111.2 111.2-113.8 Cr Cu La Mo Nb Ni Pb Sc Sr Y Zr p. 139

Table 11. Continued. Sample interval Feet 373.5-381 388-394.8 394.8-396 399-404.3 404.3-411 411-416.8 416.8-421.6 421.6-423 424-428.4 428.4-437 452-452.5 452.5-457 Meters 113.8-116.1 116.1-118.2 118.2-120.3 120.3-120.7 120.7-121.6 121.6-123.2 123.2-125.2 125.2-127.0 127.0-128.5 128.5-128.9 128.9-129.2 129.2-130.5 130.5-133.2 133.2-135.0 135.0-136.8 136.8-137.7 137.7-137.9 137.9-139.2 Au As N N N N N Hg Fe Mg Ca Ti Mn B Ba Co p. 140

Table 11. Continued. Sample interval Feet 373.5-381 388-394.8 394.8-396 399-404.3 404.3-411 411-416.8 416.8-421.6 421.6-423 424-428.4 428.4-437 452-452.5 452.5-457 Meters 113.8-116.1 116.1-118.2 118.2-120.3 120.3-120.7 120.7-121.6 121.6-123.2 123.2-125.2 125.2-127.0 127.0-128.5 128.5-128.9 128.9-129.2 129.2-130.5 130.5-133.2 133.2-135.0 135.0-136.8 136.8-137.7 137.7-137.9 137.9-139.2 Cr Cu La Mo Nb Ni Pb Sc Sr Y Zr p. 141

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