ALBERT B. FALL, Secretary
UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, Director
Bulletin 735-J
THE LOS BURROS DISTRICT, MONTEREY COUNTY CALIFORNIA
BY
JAMES M. HILL
Contributions to economic geology, 1922, Part I
(Pages 323- 329)
Published April 28 ,1923
UBRARY . 0"" $f{PH£H f U\IUMENTS J)fPT . •u·~~STitf STAT( UNIVERsl'f'(
~QQQfES • .lt1C4s·
WASHINGTON GOVER NMENT PRINTING O FFIOE
1923
THE LOS BURROS DISTRICT, MONTEREY COUNTY, CALIFORNIA. '
By JAMES M.lhLL.
INTRODUCTION.
The following notes concerning the metal prospects of the Los Burros district, in the southwestern part of Monterey County; Calif., • are based on observations made during a visit of a few days to this section of the Santa Lucia Range in February, 1921. The author is under obligation to the few operators in -the region for their many courtesies, particularly to the owners of the Gorda properties and the caretaker at the Buclimo mine.
The district lies on the ·west side of the rugged Coast Range, near · the south line of Monterey Count}", in Tps. 23 and ·24 S., R. 25 E .. Mount Diablo meridian. Most of · the properties· are near . the Government mail trail between Jolon, east of San Antonio River, and G_orda, a small ranching settlement on the coast about niidway between Monterey and San Luis Obispo. It iS reached from King City, a station on the Coast Line of the Southern Pacific Railroad at the south end of Salinas Valley, by 45 miles of road and 14 miles of rough, steep trail. · Travel except on the trails is next to impossible, because of the dense tangle of scrub oak, madrona, and manzanita. There is a fair stand of spruce and pine on the ·upper slopes of the mountains, and redwood is found in the canyon bottoms on the coast side of the range at. elevations as great as 2,000 feet. Most of the prospects are confined to the drainage basin of Will9w Creek and the headwaters of Alder Creek, a smaller stream south of Willow Creek.
TOPOGRAPHY.
· The Coast Range in this region is 12 miles wide and has a rather even sky line approximately 3,300 feet above the sea and 2,000 feet above the low country to tlie east. · The summit of the- range is 5 to 6 miles east of the coast line. This narrow mountain wall is intricately cut by deep, naiTow gorges, and in consequence the surface is extremely rugged, as is well shown on the Cape San Martin topographic map issueq~,by the :United States Geological ·Survey. · The only' flat areas in the mountain region are remnants of old
beaches, now found elevated above the sen.. The highest remnants 323
324 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1922, PART I.
noted are at an elevation of 900 feet, but the largest, upon one of which Gorda is located, are about 100 to 200 feet above sea level. South of Cape San Martin, however, there are well-developed beaches which stand 500 feet above sea level.
GEOLOGY.
The whole district is underlain by rocks of the Franciscan formation. No intrusive rocks other than the serpentinized basic dikes so characteristically associated with the Franciscan were noted, though intrusive granite occurs in the mountains at the headwaters of Nacimiento River. No attempt was made to map the irregularly distributed masses of serpentine, but there appear to be two more or less continuous belts or dikes, lying about 2,000 feet apart and trending in a west-northwest direction, which run through the south-central part of the district. The · most conspicuous exposures of the southern belt were noted along Spruce Creek, in the vicinity of the Gorda mine, and at the head of Alder Creek, near the Buclimo camp. The northern belt is well exposed along the south wall of the canyon of the South Fork of Willow Creek. The serpentinized rocks are almost completely altered, but a fsw specimens taken from the center of a particularly large outcrop indicate that the original rock was a peridotite.
The Franciscan formation as exposed here is made up of dark greenish-gray arkosic, micaceous sandstones, in general fine grained but passing into fine conglomerates that are usually noted as lerises rather than as continuous beds. Although sandstone predominates, a large amount of the rock weathers like shale, because of the fineness of the constituent grains and the parallel-distribution of the mica. The most abundant constituent t>f the sandstone is quartz, but orthoclase and plagioclase feldspar is only slightly less abundant. The dark color of the rocks is due to an unusual amount of hornblende· and biotite. Near the serpentine area8 the sandstone is altered to · contorted.schist, much crushed and sheared an.d cut by veinlets of quartz and calcite. In places in the ·vicinity of the basic ·dikes considerable bodies of massive sandstone have been thoroughly impregnated with minute crystals of garnet and pyrite.
All. the rocks weather rusty brown, but there is a noticeable difference .betwe~n the colors developed by' weathering of the rocks in the . deeper, canyons and those near.·the sumniits of the ridges. The · sandstone is massive; with little evidence of bedding, but weathers·. rapidly in small angular pieces .that disintegrate readily into a brown · sandy cl&.y. The conglomerate leilses are usually composed of small : rounded .or;egg-shaped pebbles of pinkish feldspar, white quartz, and : black:slate. · ln·.a f.ew pla~, however;Jenses of coarse arkosic sandston~,·· ,wit:Jl~ smtill,; flat, angular.: pieces· oLblack slate, were noted. :
LOS BURROS DISTRICT, MONTEREY COUNTY, CALIF.. . ·325
Only one small lens of radiolarian chert was seen; this lies at the head of Alder Creek a short distance from .the New York mine.
There seem to be two rather distinct .facies of the Franciscan formation ip. this _distri~t. The rock exposed in the lower parts of the canyon weathers in larger and more angular blocks of darker color than the overlying rocks that are exposed along the mail trail near the Buclimo mine and on .the upper part of the ridge n,orth of Willow CI:eek canyon. So far as known, serpentine does not occur in the overlying rocks. These upper rocks weather in small fragments, more like shales, thqugh fresh exposures show that they are . fine
. grained sandstones, composed of essentially the same ·materials as the slightly coarser sandstones of the lower series. .
Tlte heavy growth of underbrush and the deep accumulations of broken rock and soil, even on steep slqpes, mak~ study of the struc-
. ture very difficult. Practically all the readings taken on the west side of the summit gave strikes of N. 50°-70° W. and dips of 20°-60°
- ~· East of the summit the strike is more nearly N. 45° W. a.n,d_ the • dip 65°-70° NE . . It .is judged .that this particular part of the Santa Lucia Range is. a. monoclinal tilted block, lying between. a fault whose escarpment forms the nort;heastward-ff1,cing. w11.ll along Nacimiento River and another fault represented by. t4e s<;:arp along· the coast. These faults trend approximately N. 4oo· W~ .The trace of .a :major fault trending~. 70° w. is indic~ted by a serie~ of qenche~ and depr~sions on the south wall of the South F0rk of Willow: Qanyon, about midway between the two larger serpentine dikes. The struc-
. ture is probably complex in detail, for much evidence of minor movement, both parallel to and across. the general structure lines, is seen in every exposure.
IDSTORY . OF MINING.
The· Los Burros district was organized in 1876,' though little but placer mining was done in the region until 1887, when the Last Chance (Buclimo) deposit was discovered by W·. D. Cruikshank. Before· that time a small quantity of gold was 'produced yearly by Chinese, who washed the gravels Qf San 'Antonio Riv.er in the vicmity of. Jolon, · and a little ragged coarse · placer ·gold had· been recovered froin the ravines of the Santa Lucia Range near the coast. Cruikshank's discovery at the h~ad of Alder Creek caused ·only a mild excitement, for the region was rugged, and transportation of supplies and equipment was difficult. Iri four ·months after the discovery of the Last Chance· sufficient free gold had been saved from the surface workings to pay for the ·installation of a 3-stamp mill and small boiler on the property. The developments; consisting of open cuts, shafts, and drift tunnels that attained no great depth, showed three
'lrela~, William, CaUCornla State Min. Bur. Eighth .Ann. Ropt., pp. 405-410, 1888.
826 oo:NTR!BUTiONS TO ·E06NOMIC GEOLOGY, 1922, PART I.
nearly· parallel quartz veinlets, lying parallel to the bedding of sandstones. A group of claims, including the Mars, Manchester, Grand Pacific, and Ophir, was located ·n.e·ar the original discovery, and the Stonewall and Brewery, farther west on Willow· Creek, were located during the same year. · ·
Apparently little was done in the district after 1888; except at"the Last Chance mine, for 'the next record of the State mineralogist is for the year 1892.2 By that time the Last Chance had reached a depth of 160 feet. · ·
Practically all the mining in the district was confined to the mines on Alder Creek until1902, when the discovery of a few very large gold nuggets ·on Spruce Creek led to the organization of the Gorda Mining Co., which has done some work to locate the veins that were the source of this coarse gold. About the same time placer gold was found in the gravels of Willow Creek, and very rich quartz float was found on the Plaskett property, called the Ocean View. The Bushnell vein, on the point between Willow Creek and its North Fork, at an elevation of 1,600 feet, was discovered about 1904, and more recently croppings showing copper-stained pyritic sandstone have been prospected· in the canyon of the South Fork of Willow Creek, about 2 miles north of the Last Chance mine. The Last Chance and sevetal other properties in the vicinity are now controlled by the Buclimo Mining Co., and the original nai:nes have been ·more or less lost. This company found the upper workings in such state that it began to drive a long crosscut from Alder Creek to tap the veins at a dep~h of about 400 feet, but this project was not completed.
The total production of the Los Burros district is estimated at $90,000.3 The records of the United States Geological Survey show a production of $4,746 in gold and silver for the period 1905-1908, most of it from siliceous gold ores. During another period of activity from 1912 to 1914 a total of 329 tons of siliceous ore was treated, and the total production of the district, including .a small quantity of placer gold, was valued at $14,4.19. There is no record of production fro~: the district since 1917: .
~n the winter of 192~21 a little development work was ,done on the Bushnell, Gorda, and New York pr~perties and some surface work at the Melville and Hammond prospects, on the south side. of Willow Creek. · ·
ORE .DEPOSITS.
The prizlcipal mineralization of the district is in the vicinity . of the serpentine belts, and the greatest amount is at the head of Alder Creek, near the Buclimo, Grizzly, and New York properties. In
1 California State Min'eraloglst First Blenhial Rept., lor the two years ending Sept. 15, 1892, p. 259. 1 Calllornia State Mlnefalogist Filteenth Ann. Rept., p. 597, 1916.
· LOS -BURROS : DISTRICT, MONTEREY COU·NTY, 'CALIF. · ·ff27
:this locaJity! r~atively ·na.rrow. .quaxtz stringers; from ·half an inch ·to 2 ·hl!}hesJn;width, that strike N. 70~-85°· W. and :usually dip 60°~5:0
~_N., 'lis.pai'allel to the. major structural features. : ,.CalCite and siderite .-in ,minor ;amounts are associated with the quartz in most . places. cnnda.tion is l'elati:v:ely.·shallow, and in some' pits sulphides axe :found directily . a.t · the surface.:- ·The oXidized .surface . ores are largely :I.i.n),onite-stained. bodies o_f crushed sandstone, with more . or lass ·quartz, and carry free gold, · The sulphide·.ores, which.-were visible at-.;only ·a few places in .1921, consist of sa.ndst·one cut by: :Veinlets of quartz .and. a little calcite,,. which have been crtlshed and la.tei. min.e.rsJ.ized. . The sulphides are pyrite, arsenopyrite, and minor ·amounts of chalcopyrite, sphaleri~e, and occasionally. a speck of galei).a. The sulphides are.usually confined to the immediate vicinity ·ofthe quartz ·veinle.ts.;.though in a. few places :finely disseminat.ed pyrite, 'with much less. chalcopyrite, is diffused thxough the sandstone for several. feet :from the 'Veinlets. Practi~ally all the -gold produced.fro:m: the lodes in the district has been extracted from· relatively small -lenses . of oxidized ore, which required only amalgamation for treatment. -It is: douh.tful if the sulphide ores are· sufficiently.rich :to stand the cost of.tra;n,sportati.on and treatment by smelting. · . · . c:. : .:· . · . : At· the .New York: property, .on Ajax.Mouil.ta.in near the 'sU:minit, .t.Wo ,n:arro;w .. v~inlets; about 18 inches· apart, ,.constitute ·· the.lode.. :The· G:t:W3hl!d,. contorted rocks between· the veinlets carry.pyrite· and ·8J'Senopyrite; with v:eri ·minor ·amounts of .chalcopyrite and galena. Complete ·oxidation on this lode has extended to: a depth of 50 feet, and mining tt>' that depth has yielded some fairly. goodfree-,gold ore. Two tunnels, a few hundred feet in total length, have been driven in the sulphide zone.· The sulphides are in very small .crystals and ·appear to .have· been deposited . subsequently .to a period of crushing of the m:iginal quartz veins. Arsenopyrite predominates over pyrite. · . . ::·The Grizzly ledge, ·in the bottom of the.Alder Creek viilley, between .the:New,York-and Buclimo properties, measures 3 to 4 .feet. between ,walla. ; ,The ledge :matter. is crushed sandstone, with stringers of 9~diz.ed .quart~ . and ~. little calcite. The-incline on the ledge, which dips, 75°.N:., is:said to be 80.feet deep .but was partly :filled with water .at the,;time.of visit. · · · · .... , The: l3uclin:10 .(Last Chance) workingS .were not accessible. .From th~. ~wface: work it is judged.-that at lellSt fo_ur nearly parallel lodes ¢,st: Qn.' tlle . property. · These .strike N. · 80°' .W.; and, to: judge: frpm the northerly dips at the surface, the ledges may come together with ~llpth~ . It is said .:that from the surface to the tunnel level, '85:feet belo:w, the lode has. been stoped for a width -of 10. feet •and a length of. 500 feet . .. A Jittle ore,- ,presumably .. from the tunnel :level, found in a . mill!. bin show~d quartz-calcite veinlets, .with pyrite and arsenopyrite in ,crushed, s9mewhat mineralized dark-colored sandstone and
828 CONTRIBUTIONS To ECONOMIC GEOLOGY, 1~, PART I.
shale. The upper workings are reported to be abandoned now, and a long crosscut tunnel hns been started from the level of Alder Creek, near the Grizzly incline. This crosscut is more than 1,800 feet long but has not reached the vein. It was run in a direction almost parallel to the vein and the strike of the sandstone beds. The first 200 feet of the crosscut is in medium-coarse sandstone; next there is 100 feet of black chert; and the remainder of the tunnel is in nearly black sandstone that is almost :fine grained enough to be termed slate. This tunnel shows the formations to be very much broken and faulted, most of the movement being parallel to the bedding in dip as well as in strike, but with many planes of minor movement showing parallel strike but much steeper dip than the bedding.
The Melville claims, on the ridge between Alder and Willow creeks, appear to be a westward continuation of the Buclimo. A large open cut just below the trail exposes a much crushed zone of sandstone about 10 feet wide, with stringers of quartz that strike N. 70° W. and dip 50° N. It is said that all the material from this zone shows some gold. ·
The Brewery tunnels are north of the trail, about 200 feet down the slope toward Willow Creek from the mail-trail ridge and 1 mile west of Melville's cabin. They were caved at the time of visit but apparently were run on a ledge that strikes N. goo W. and in the cuts dips 60° S. As exposed in the cuts the ledge matter is 6 feet wide and consists of :fine-grained black sandstone, with veinlets of quartz and a little siderite. No sulphides were seen on the dump, but small casts of cubical outline :filled with limonite indicate that the mineralization is similar to that at the Buclimo.
In the canyon of the South Fork of Willow Creek F. C. Hammond has several prospects on N. goo W. zones of mineraliz.ation in the slates and sandstones. The metalliferous minerals here consist largely of disseminated pyrite anc;l chalcopyrite in_ hard darkcolored· sandstone along a series of nearly vertical tight · fractures. No arsenopyrite was noted. There is practically no oxidation on any of the ledges, though a little iron and copper stain is to be seen directly at the surface. At one of Mr. Hammond's claims, on the I;'idge between South Fork and Willow Creek, pyrite and a little chalcopyrite are disseminated along a shear zone in garnetized sandstone about 25 feet from a lens of serpentine. Very minor amounts of copper silicate and limonite coat the joints at the surface.
The Gorda property is on Spruce Creek in sec. 4, T. 24 S., R. 5 E. In 1902 several exceptionally large ragged gold nuggets were found in the stream bed near by. Considerable money was spent in equipping the property for hydraulic work, and a little -more gold was obtained. The talus and soil cover, however, were so deep that the
LOS BURROS DISTRICT, MONTEREY COUNTY, CALIF. 329
stream gravels had not been reached except over a short distance. A number of tunnels have also been run in talus to locate the rim of the covered channel, and some wor~ has been done in the sandstone on the north wall of the gulch in the hope of discovering the source of. the coarse gold, but this objective had not been reached in 1921. The sandstone cut by this tunnel is peculiar in that it contains small flat fragments of black slate, minute red garnets, and a small amount of finely disseminated pyrite. The mineralization is localized in the sandstone within 150 feet of a considerable outcrop of serpentine.
The Bushnell property is on the point between the Middle and North forks of Willow Creek. The developments consist of an inclined shaft and a crosscut tunnel, 330 feet in all. The incline is sunk 130 feet on the intersection of a north-south fracture that dips 50° E. and aN. 50° E. stringer that dips 50° SE. It is reported that about $9,000 in free gold was milled from the ore obtained in sinking this shaft. At the tunnel level the north-south fracture is barren; theN. 50° E . fissure ranges in thickness from a knife-edge to 8 inches and is filled with white quartz, calcite, and fragments of wall rock, the whole much crushed and shattered. A little free gold is visible in some of the quartz, but no sulphides, limonite, or· other indications of the former presence of sulphides were noted in the ore.
The Ocean View (Plaskett) property, on the west slope of the ridge west of the North Fork of Willow Creek, in sec. 30, T . 23 S., R. 5 E., is developed by an 86-foot incline, with short drifts to the northwest" at 40 and 80 feet and a 100-foot drift tUn.nel to the southeast on the 40-foot level. The ledge strikes N. '45° W. and dips 10° NE. at the surface but steepens to 60° at the bottom of the incline. It consists of crushed white quartz, slightly iron stained but with no visible sulphides. It is reported that $18,000 in free gold was recovered from float picked up below the croppings and from ore obtained in sinking the incline. It is judged that the free gold occurred in a small lens, for the quartz exposed in the workings appears to. be barren.
The placer gold found in small quantities in practically all the gulches but particularly on Spruce and Willow creeks was derived from the weathering of small veinlets similar to those ilisclosed in the properties described above. Most of the placer gold is in small ragged particles that have not traveled far from their source. The large nuggets found in Spruce Creek evidently came from a particularly rich pocket in the immediate vicinity.
The mineralization of the district is not particularly strong, and, although there may be further discoveries, near the surface, of pockets containing free gold, it is believed that all that can be expected below relatively shallow depths will be rather small bodies of pyritic ores of relatively low tenor.
12456°-28-2
INDEX.
A. ·Page.
Acmowledgments for aid . . . . . . . . . . . . . • . . . . . H 42, 65-66, 131, 280-281, 323
Alleghany County, N.C., tltanirerous magn&-tites in. . . . . . . . . . . . . . . . . . . . . . . . . . 252
Alluvium, nature of,ln Pike County, Ark .. 292-293 Alta mine, Comstock lode, Nev., microscopic
details of ore from ...... . .. ...... . 48-49 American.area, Ark., location of .......... 280,289
nature and relations ol peridotite ln ... 306-308 American mine, Ark., map showing distribu-
tion of peridotite at......... ..... 30i operation of............................. 288 production from. . .......... ... .... ...... 318
Andes mine, Comstock lode, Nev., micro-scopic details or ore from......... 57
Andrews, N. C.,. brown hematite deposits , northeast of ....... . .. ......... 192-193
brown hematite deposits southwest of. 185-187 Andrews area, N.C., he.matite deposits ln . 188-192
structural features of. ......... 187- 188 Andrews schist, in Cherokee County, N.C.,
geologic features of....... . ...... .. 167 in Cherokee County, N . C., hematite d&-
posltsin .. . .. ................. . 182-183 Argentite, ~res bearing, in the Monte Cristo
mine, Ari% ... ............... ... 141-145 Argentum mine, Candelaria, Nov., descrip-
tion of.. ..... ~ ...... ......... 4-5,17-19 Arkansas, southwestern, geologic map ol
parter........................... 280 Arkansas Diamond Co., aclmowledgment
. to ............. : ............... 280-281 Arkansas mine, Ark., diamonds from, plate
. showing......................... 3'20 equipment and operation of.. .......... 286 productionfrom... ... . ... .. . . ... . ...... . 318
Ashe County, N. C.,siliceous magnetitein .. 216-220 titaniferous magnetites' in . . . ..... .. . . . 251-252
Atlas mine, near Sneffels, Colo., nature and origin of ores of .. . ..... . . . .... . .. 74-75
AveryCounty,N. C.,slliceousmagnet ite in 220-231 titaniferous magnetites in... . ....... . . . . . 253
B. Bachelor mine, Ouray, Colo., nature and
origin of ores or. .. ............ 70-72, 73 'Ballou " home place," Ashe County, N.C.,
magnetite d'eposit on .. .... 217, 218, 219 Bastin, Edson S., Bonan%a ores of the Com
stock lode, Virginia City, Nev ... 41-63 Primary native-silver ores near Wicken-
burg, Ariz ........... . ......... 131- lSS Silver enrichment in the San Juan Moun-
tains, Colo .. ................... . 65-129
Page. Bayley, W . S., General features of the brown
hematite ores of western North Carolina ......... .. . ...... ..... 157-208
General features of the magnetite ores of western North Carolina and east-em Tennessee .... . ..... ...... . 209-270
Becker, 0. F .,studyoftheComstocklodeby. 43 Belcher mine, Comstock lode, Nev., micro-
scopic details of ore from . . . . . 48, 52-M Bessemer City, N. C., hematite mines near. 20H?08 Big Ore bank, N. C., dCscrtption of .. . . ..• • 234-235 Bingen formation, nature and occurrence of
in Pike County, Ark ........ .. ~1-292 Black Lick, Ark., map showing distribution
of peridotite at. ...... .......... . 304 Black Lick area, Ark., location of.. .... . ... 280, 289
nature and relations of peridotite ln ... : 308-310 prospecting on... . .. .......... . .. . ....... 288
"Blue ground," In Ozark mine, Ark., plate showing........ . ... ...... . ...... 296
polished, plate showing...... ... ......... 297 use or name.. . .. . .. . .. . .. .. .. . .. . .. .. . .. 295
Borax. See Colemanite. Branner , J. C., cited ..... . ....... ...... . ,.... 304 Brasstown, N. C.,hematitenear .. ......... 197, 198 Brasstown belt, N. C., description of....... . 197 Breccia , volcanic, in Ozark mine, Ark., plate
showing.......... . ........ ...... 296 volcanic, pollshed, plate showing..... .. . · 297
Brewery tunnels, Los Burros district, Calif., description of.. .. .... ... ......... 328
Brownstown marl, nature and occurrence of, in Pike County, Ark.. ... .. . .... 292
Bucllmo mine, Los Burros district, Calif., description of.. .... . ...... .... . 327-328
Burra mine, Ducl.:tow'n , Tenn., composition of mino water from.............. 107
Bushnell mine, Los Burros district, CaW., description of............. .. ..... 392
c. c. & C. mine, Comstock lode, Nev., analysis .
of water from .. ........ ....... .. . 59, 61 miscroscopic details of ore from . ... 47, 49, 50-61
Callville Wash, Nev., course of........ .... .. 24 Candelaria silver district, Nev., alteration of · wall rock in .... . ... .. . ......... . 1&-16
dacite tutr in. . .. .. .. .. .. . .. . .. .. . .. .. .. . 9-10 geography of. . . . .. .. .. .. .. .. . .. . .. .. . .. . 2-3 geology of. ......... .... .. ............... ~12
history of mlnlng in .. .... .'... .. ......... 3-S Jurassic (?) rocks in..................... 7-8 mines in .......... .. .... . ... ... .. . ....... r7-22 olivine basalt in ... .. . .. .... ~ .... ...... . 11-12
331
332 INDEX,
Page. Candelaria sliver district, Nev., Ordovician
(?) rocks ln. ... . . . . • .• . . . . . . . . . . . 6-7 ores in, composition and tenor of.. .. .... 13-15 outline of report on............... . ...... 1-2 production from.. .................... . . . 5 rhyolites ln .............................. 16-11 silver veins ln .... . .. . .•............ .. ... 12-17 comparison or, with other Nevada silver
deposits .. . ..............•....•.. 16-17 Tertiary rocks in. . . . . . . . . . . . . . . . . . . . . . . . 8-12
Carpenter, E. E., acknowledgment to........ 5 Carroll, Fred, acknowledgment to........... 66 Carter County, Tenn., tltanilerous magne-
tites in .... . ............... 253, 253-254 Catawba County, N. C., hematite deposits
reported in. .. .. . .. .. .. • .. .. .. .. . 204 magnetites in .. .... . ..... .. . ....... 233-234, 236
Central tunnel, Comstock lode, Nev:, analysis or descending water from ........ 60,62
Cherokee County, N. C., geology of the brown hematite district in............ 167-168
grouping or tho hematite deposits in . .. 166-167 hematite deposits in the Nottely River
ore belt.. .. . ................... 168-173 in the Valley River ore belt ..... : . 168-170,
174-193 sequence of Cambrian formations in ... 159-160
Chloanthite, silver ores bearing, in the Monte Cristo mine, Ariz .............. 138-139
Chromium, occurrence or, in magnetites..... 211 Clark County, Nev. Su Muddy Mountelns,
Nev. Cobalt, Ont., nature of sllver-depositingsolu·
tlons at .......... . .... . . . ..... 150-154 ores of, compared with these of the Monte
Cristo mine, Ariz ..... . .... .... 147-150 Colemanite, deposit near Callville Wash,
N!)v., discovery or........ . ...... 34 deposit near Callville Wash., Nev., nature
or.............................. . 38 nature of ore in. .. .. .. .. . .. . .. .. .. .. 38-39 origin or..... ... . . . ............ . ..... 39 platesshowing... ................... 29 strata inclosing.... . . . . . . . .. .. . . .. . .. 36-37 structure and extent of. ............. 34-35
deposits in White Basin, Nev., discovery or.. ............................. 32
nature nnd extent of.. ............... 32-33 ori~in or. ..... . .... .. . . . • • . • .. .. .. . 33
Comstock lode, depths from which samples of ores and waters were taken...... 44,
47,58,59 earlier investigations of.. . .. . . .... . ...... 42-43 engineering and geologic problems con-
cerning.......................... 41 gold in ores or, modo of occurrence or. ... 45, <W mine waters of, 8ll8lyses or ...... ....... . 59-63
flooding by . ........ .. . . ............. 57-58 · temperatures of, at different depths . 58
ores from depths of 2,500 feet or more in, microscopic dc'talls or . •...• _. .. . . 52
ores from moderate depths in microscopic details ot.. ...................... 47-52 ores from small depths in, microscopic
· detallsof . . ...... : : •• ;; .· ..... :.:. · SZ-57
Page. Comstock lode, ores of, contemporaneous
deposition of minerals comprised in .. . .... . - ... . - .......... .. ..... 44
ores of, deposition from ascending solutions .............. 42, 43, 44-45,63
enrichment by descending solutions . 42-43, 44,<W,63
mineralsin ........ - .... ............ . 43, 44 microscopic features or. ........ .. 44-47,63
silver in ores of, mode of occurrence or. .. 45-47 sources of ores and waters examined..... 42
Corinth, Ark., prospecting !or diamonds south or. ......... : .. . .. . . . . .. .. . 288
Costner mine, N. c., description of. . . . .. . . .. 237 Covellite, replacement of other minerals by. 105, 109 Cranberry mine, N. C., analyses of ore from.. 222
history of.. ......... . ...... ..... ....... 220, 221 location of. .... . ........ .': ............. 220,221 ore vein in ..................... ....... 222-227
Cranberry mine belt, N. C. and Tenn., reserves of magnetites ln ....... 229-231 ·
Cranberry vein, continuation of, beyond the Cranberry mine ..............• 227- 229
D.
Dannemora mine, N.C., ores of._ .... . .. .. 256-257 D!tvis, J. van, property, ncar Peachtree,
N. C., hematite on.. . .. . .. .. . . .. 198 De Queen limestone, description of. . . . . . . . . . 290 Dev!l's Workshop mine, N' C., description
of. ..... . ........ .............. 206-208 Diamonds, !rom t he Arkansas mine, Pike
County, Ark., plate showmg..... 320 in Pike County, Ark., description of.. 319-321
history of discovery, and mililng of. ........... ...... . . ..... .... ~288
mlnetals associated with... . . . . . . . . . . 322 m!nlng of.. ....................... 321-322 · occurrence of. ..... .. . _ .... . .... ... 316-318 production of. ............. .. . .... 318-319
outlook tor finding, in Scott County, Ark..... ..................... .. . 278
Dierks limestone, description of.. ...... : .... 290 Dockery mine, N. C., location of......... .... 174 Dunton, Colo., composition or spring and
mine waters near ...........•. . llS-119 location of. ....... .. ................... ·- 110 mines near ........ . .... . ............. . 116-127
E.
Eliot hematite property, near Peachtree, N. C., description of............. 196
Emma mine, Dunton, Colo., nature. of ores and waters of.. •• . . .•.. ... _. • • . 116-120
Enrichment, downward, in the Monte Cristo mine,Ariz ... : ............... : .. . 146
Enterprise vein, Rico, Colo., nature of ores and waters of.. .. ,.... . .......... 115
F.
Faln-R!tchcock mine, N.C., description of. 172-173 Farish, F. G., acknowledgment to. ..... . .... 66 Farrar, D. F ., analyses by. ......... ... . .... 268 Ferebee & Young mine, N . C., description
of ........... ................. ,. 188-189
INDEX. 833 Page.
Finney & Teegarden mlne, Tenn., ore bodies . and country rock3 of ••• • ••••••• 200-269
Flowery mine, Comstock lode, Nev., micro-. scopic details of ores from .••. . : . . 57
Fulenwider mine, N. C., occurrence and origin of minerals near. . . • . . • • . . . 238
Fuller, John T., acknowledgment to... . ..... 280
o. Gaston County, N.C., matnetltesln ...... . 236-239 Genesee mine, Colo., composition of waters
· ln .......... ... ... . .. ....... 1~108,109 nnture and alteration or ores ln •......• IM-109
Gold Branch, N.C., hematite on ...... 200-201,203 Gorda prospect, Los Burros district , Calif.,
description of.. ... ... · .......... 328-329 ''Goose-egg'' structure In limestone beds,
near Callv!llo Wash, Nev., plate showing.... . ... . ..... ... ..... . .. 38
Gould & Curry mlne, Comstock lode, Nev., . microscopic details of ores from
00 ... .. .... . ........... . .... . . 54-55,57 Graton, L. C., cited ... ; ... .. ...... ......... 232-233 Graybeal property, near Lansing, N. C.,
·magnetite deposit on . ..... 217,218,220 . Green, Guy, mlne, N. C., description ot.. . 179-180 . Grizzly ledge, Los Burros district, Calif.,
description of..... . ............ .. 327
H.
Hale & Norcross mlne, Comstock lode, Nev., · microscopic details or ores from
...•..... . .•...• . ...•.. . ...... 47,~56 Hall-Starbuck mine, N. C.,loeation of....... 174 Hammond prospects, Los Burros district,
Calif., description of.... ... ..... 328 "llardebank," in M!luney mine, Ark., plate
showing ••...•..... , ........... ... 296 micrographic plates showing.. ....... .... 296 nature and occurrence of ••• 0 0 0 0 0 0 0 0 0 0 0 0 305-306
. use of naiJl6.... . . • • • • • • • • . • • . • • • • . • • • • • . • 296 llayes-llobllttell mJn(), N. C.,descrlptlon of.181-182
view IQ., plate showing.... .... ........... 164 lleaton & Russellmlne, N .C., deScription of. 178
hydraUucjetin, plateshowing .. .'..... . .. 164 ore vein in, plate showing .. . .... . , ..... . Hl5 view in, plate showing................... 164
lle!ller, W. G., acknowledgment to......... . 42 llematite, brown, analyses of .• 175, 181,182,184,189,
191, 192, 205, 206, 'JJ1l brown, distribution of................. .. 158
earlier reports on ......•... ...... . . 157- 158 mining or. ..... 163, 169-170, 188-189, 190-191 nature or.. . . . . . • • . . • . . . . • . . . . . • . . . . . 163 origin and age of ............. .. . ... 160-163 residual deposits of .....•.... ·...... .. 163 ·
lllll, James M., The Los Burros district, Monterey County, Calif .. . ..... 323-329
Rinds, J. I. N ., analyses by ..........• 245, '}1)7, '}1)8
lll wassee and· N ottely rl vers, N. C., hematite deposits between . •.... . ••..... 201-204
lllwassee River, N. C., hematite deposits · nortlrof .. . ..... . ...... ...... .. 197- 198
hematite deposits south or ............ . 198-199 Rolland, L. F. S.l acknowledgement to...... 66 llolmes mille, Candelaria, Nev., bistory or... 4,18
Page. Horse Spring formation, exposures of lime
stone member or, in Clark County, Nev., plates showing... 28
nature and distribution or, in Clark County, Nev ............. ....... 28-30
Humboldt mine, Colo., nature of ores and waters of. ........ . . .. . .......... 7!H!3
I.
Irving, J.D., cited.......................... 73
J.
Jenkins, t:. L., hematite property of. ..... 183-185 Jumbo No. 3 vein, Rico, Colo., nature and
alteration or ores in ............ 112-113
K.
Keith, ~rthur, cited................. . ...... 164 Kerr, W. C., and Hanna, G. B., clted .. 234,237,2S1 Kimberlite area, Ark., exposures of peridotite
dike in ....................... . 304-305 location or ..................... ... ..... 280,289 metamorphosed Trin.l ty clay in..... .. .. .. 305
Kimberlite Diamond Mlnlng & W!IBhing Co., acknoY<ledgm~t to ... .... . .... 280-281
Kimberlite mine, Ark., map showing d.lstributionorperidotlteat............ 304
opera~ion of . . . .••... ~ •.••.. ..•.•.....• 287-288 trenches ~11, plate showing.... ...... ... .. 320
Kimberlltes, of 4-rkansas, 81).8lyses ot.. .... .. 316 of S9uth Mrica, analyses of. .. . .......... 316
origin of pipes or.. .... . .. , ......... 312-313 King, Clarence, study of the Comstock lode
by. 0 0 ... : ................. .-..... 42-43 Knopf, Adolph, The Candelaria silver dis-
trict, Nev.................... . .. 1-22 Kunz, G. F.,and Washington, ll. S., cited . .. 319
· L .
Lansing mine, N.c., ore or ................ 242-248 Lesley, J.P., cited ........................ 23~240 Liberty Bell mine, Colo., ores of ............. . 89-92 Limon!tes, occurrence of, In Gaston County, .
N.C ............... ........... 236-237 Set aZ.o Hematite, brown.
Lincoln County, N.C., magnetites ln ..... . 233--236 Lincolnton, N. C.,'hematite deposits reported
near............................. 204 Little Missouri River below Prairie Creek,
perldotiteoo..................... 304 Little Mountain mine, N.c., description of. 206-208 Longwell, C. R., geologic work of, on the
' Muddy Mountains, Nev .......... 25-26 Los Burros district, Calif., geology of ...... 324-a2S
history ofmlnlng in ................... 325-326 location of.. .. ................ . .......... 323 ore deposits in .... ..................... 326-329 placer gold In,........................ ... 329 topography or.. .. . .' .. . ...... . ......... 323-324
Lucky lllll"mine, Candelaria, Nev., descrip-tion of .. ...... .. ........ .... . .. 5, 20-22
Luther, George :a:, hematlte prospect of, near . Andiews, N. C .... ; ............ . 185
MCCarter plf\ce, Ashe cOuntY, N. C., mag-. netiteoreon ................... 251,252
McCormick, Thomas, acknowledgment to.. . 42 McHanintne, N: C., description of . ........ . 180-181
334 INDEX.
Page. Madison County, N. C., distribution and
mode or occurrence or brown hematite ores In............... 163-166
sequenceorCambriauformationsiu .... 159-160 tl taulferous magnetites in. . . . . . • • • . . . . . . 253
Magnetic City, Tenn., magnetite deposits near ..................... . ..... 228,229
Magnetite-hematite ores or North Carolina and Tennessee, nature and dis-tribution or .................... 261-269
origin of.. ... : ................ . ......... 269-270 reserves or.. ........... ... ......... ,. .... 270
Magnetit&-marble ores, nature and occurrence or, in North Carolina .... .. .... 242-248
origin or ... ........... .... .... ......... 248-250 reserves or............................... 250
Magnetite, siliceous, deposits or .. .......... 214-242 siliceous nature or. ....... ............. 213-214
Magnetites, chemical composition or......... 211,
218,235, 239,254,256-257,258, 267 In western North Carolina and eastern
Tennessee, geology of the district containing ................... .. 214- 215
production and general distribution ·of ................. .. .......... 209- 2ll
reserves or ............. ... .... ..... 229-231 varieties or. ...... ............ ..... 211-213
nontitaniferous, general features of. ...... 213 kinds and deposits or. .... ... . ..... . 215-250
tltaulfcrous, composition or.. .......... 258-260 deposits or.. ...... . .......... ...... 251- 259 nature of ..................... . .... 250-251 origin of.. ......... ................ ~261 utilization or....... .. . .. . .. .. .. .. .. . 261
Manganese, occurrences of, in western North Carolina and eastern Tennessee.. 171,
198-199, 202,203, 211 Marble, N. C., brown hematite deposits east
and south of. ................. 180-185 brown hematite deposits southwest of. 178-180
Marble Creek, N. C., hematite deposits near ............ : ............. 176-1n
Martin Creek area, N. C., areas of marble ·ln .. . .................. . ...... 199-201
. hematite deposits ln .... . . · .......... , .. 200-201 Marvacar mine, N. C., description or.. .... 100-191 Mauney, Walter, acknowledgment to.... .... 281 Mauney mine, Ark., equipment and opera-
tion of. ....................... : 286-287 plate showing... ........................ 296 production of........ .... ................ 318
Mauney property, near Murphy, N.C., hema-tite mine on ................... 202-203
Melville claims, Los Burros district, Calif., description of.... ....... ......... 328
Merrill, George P., acknowledgment to...... 42 Mexican mine, Comstock lode, Nev., micro-
scopic details or ore from .. . ..... . 51, 5~ Millar, Austin Q., cited .. : ................. 320-<121 Mine waters, action or, in the enrichment or
silver ores .. . . ...... 96-97, 109, 127-128 nature of... .. .. .. .. .. .. .. .. .. .. .. .. .. .. 88,
105-108,109,112,117-119, 123, 125-126, 128-129 test or, from the Humboldt mine, Colo. . 83
from the 'Monte Cristo mine, .Ariz, ... 146 from the Smuggler-Union mine, Colo. 88
Miser, Hugh D., and Ross, Clarence S., Diamond-baarlug peridotite In
Page.
Pike County, Ark .. ........... 279-322 and Ross, Clarence S., Peridotite dikes
in Scott County, Ark ........ .. 271-278 Mitchell County, N. C., titaniferous magno-
titesin. . . .. ............ .... .... 253 Molybdenum, occurrence of, near Shell Creek,
Tenn ............... ............. 229 Monte Cristo mine, near Wickenburg, Ariz.,
argentite-bearing ores in .. .. . .. 141-145 bedrock formations at ................. 131-132 chalcopyrite type or ore ln...... ........ . 133 chloanthite-bearlug silver ores ln ...... 138-139 distribution of rich silver ores in ..• .... 133-134 downward sulphide enrichment in....... 146 gold oresln.. ............. .......... ... .. . 145 miuewaterslu.......................... 146 nlccolite-baaring silver ores ln ......... 134-137 ores carrying ruby silver ln ............ 13~141 ores of, compared with those of Cobalt,
Ont . .. .. .............. .. .. · ... 147-150 oxidationin . . ......................... 145-146 primary native-silver ores of. .......... 131-155 structural features of the veins ln .... . . 132-133
Monteitbmlno, N.C., description of......... 200 location or.. ................ .......... . 197,199
Montvale, N. C., brown hematite deposits northeast or. ...... ............ 177-178
brown hematite deposits southwest of.. 174-1n Morgan Creek, N. C., brown hematite deposits
northeast or. .................. 178-180 brown hematite depositssoutbwest of.. 1n-178 brown hematite reserves near... .... ..... 178
Mount Diablo mine, Candelaria, Nev., de-scription or.. ................ 4-5, 1~20
Mountain Top tunnel, Colo., nature or ores cut by ..... ...... ...... ......... 78-79
Mountain View mine, Butte, Mont .. composition of mine water from........ 107
Muddy Creek formation, features or, in C~rk County, Nev ........... , ........ 30-31
Muddy Mountains, Nev., colemanite deposits in .... ........................... 23,25
geography or ... .. : . ........••... . ....... 24-25 geology or. . . ...... ............... .. ..... 26-31 igneous rocks in and near ... , .... ........ . 31
Murphy, N. C., brown hematite deposits northeast or. ...... .......... .. 174-177
Murphymarble,quarry in, in western North Carolina...... .. ...... .... ....... 176
N. New River, North Fork or, N .C., magnetite
deposits on ....... . ............ 216-220 New York mine, LOs Buiros district, Calli.,
description or.. ................ 320,327 Newsboy mine, Ouray, Colo., ores or.. ........ 73-74 Niccolite-bearlug silver ores near Wicken-
burg, ,Ariz .. ................ ... 134-137 Nitze, H. B. C., cited ................... 235,251,254 Noble, L. F ., Colemanite In Clark County,
Nev .. ........................... 23-39 North Carolina, molmtain district or, rocks
nssociated with brown hematite · oresln .. ...................... . 158-163
western, magnetite ores in ..... . . .... ... 209-270
INDEX. 335
Page. Northern Belle mine, Candelaria, Nev.,
history of.. .................. 3-4,17-18 Nottcly and mwassee rivers, N.C., hems· ·
tite deposits between . ......... 201-21» Nottely River hematite belt, N. C., descrip- ·
tion ofminein ........ ......... 172-173 location and nature of deposits in ... . ... 170-172 reserves or ore in ............... 171,172,193-191
Nottely·Valley River belt, N. C., geologic map of........ .................. 162
0.
Ocean View mine, Los Burros district, Catil., description or.................... 329
Ophir mine,. Comstock lode, Nev., micro-scopic details of ore from.. . . . . . . . 52
Ormond mine, N.C., description of.. ... . ... 204-206 Ouray, Colo., composition diagram of spring
water from . . . . . . . . . . . . . . . . • . . . . . 61 Ouray-Telluride region, Colo., geologic
features of .... ..... .. ...... .. ...• 6(Hl7
origin and enrichment of ores in ......... . 92-97 Overton fanglomerate, nature and distribu·
tion ol,in Clark County, Nev. 27,29-30 Owensby, R. R., property, near Murphy,
. N. C., hematite deposits on and near....... ...................... 203
Ozark mine, Ark., equipment and operation or.. .... .... . :. ..... .. .... ........ 287
plates showing........................... 296 production ol....... . .................... 318
P.
Palmer, Chase, acknowledgment to .. ........ 61Hi6 analyses by ..... .. ............ ... 59, 68, 108, 119
Peachtree area, N. C., brown hematite de-posits in . ........... ....... 191-197,198
Peg Leg mine, Tenn., location and ore vein ot ........... . .. . . . ..... . .... ... 228,229
Peridotite, exposures. of, in the Mauney mine, .f>.rk., plate showing. . ..... 296
hypabyssal intrusive, micrographic plates showing............. . . . ... 296
Peridotite dike near Olio, Ark., micrographic plates showing......... . ......... 276
Peridotite <likes in Scott County, Ark., eco-nomic features of. . . . . . . . . • . . . . . . 278
location and history or .. ........... 271-272 position and nature or ..... . .......• 273-278 rocks associated with .............. 272-273
Piedmont area, N. c:, magnetite deposits in, distribution and general geology or.. ......... ................... 231-233
magnetite deposits in, origin of. ........ 239-242 reserves ol.. . .. . . . . . . . . . .. .. .. .. . . . . . 242 workings on .... . . ...... ... .. .. . ... 233-239
tltanl!erous magnetites in ........... .. . 2:>4-258 Piney Creek, N. C.,magnotitedepositson.. .. 217,
218,220 Pike County, Ark., diamond area, location
ot .. ... .... .... .. ....... ... ..... 279-280 peridotite area, bibliography o! ......... 281-285
field work on.... . ............ ....... 280 geography ol . . : . . .... ...... ... .... . 288-289 geology or . .... .......... .......... 290-316 history o! diamond mining in .... . .. 285-288 population and transportation in... . 289
Page. Pike County, Ark., peridotite in, age o!. ... 310-312
peridotite In, relation of, to other Igneous rocks of Arkansas..... . . .. . .. . . .. 310
Pike gravel mr.mher, Ark., description o!.. 290,291 Potosi Mountain, CanMlaria district, Nev.,
sliver deposits on........... .... . 22 Prairie Creek, Ark., peridotite dike near
mouth of ... ... . .. ........... .. 303-304 Prairie Creek area, Pike County, Ark., geo-
logic map of.. . ................. . 2ro location and topography o! ........ 279,289, 293 peridotite In, hypabyssal intrusive type
of ..................... .. ..... .. 296-298 less common minerals in............. 300 micrographic plates showing...... .. . 296 nature o!. . . . • . . . . . . . . . . . . . . . • . . . . . 295-302 rocks associated with ....•.......•. 293-295 type of, comprising tuffs and ftne-
grained breccias .............. . 301-302 veins ln. . . . . . . . . . . . . • • . . . . . . . • . . . . 302-303 volcanic breccia type of .•.......... 291Hl00
Pratt, J . H ., cited ......................... 217,219 Proust! to. See Ruby silver. Puett mine, N. C., description of .. . _... ..... 180
R .
Ransome, F. L., cited ... .... . . ........• 99,104, 112 Rathmell, William, acknowledgment to..... 66 Red Marble Gap, N. C., hematite deposit at. . 193 Red Mountain region, Colo., composition dia-
gram of deseending mine water Crom.... ................. ... .... . 62
geologic fl!atures of ...... .. . . . ... .. ....... 98-99 ores of. ........ _ ........................ 98-104
Rhodo, N.c., hematite depOsit south o!. . .. . 193 Rico-Aspen mine, Colo., ores of.. ....... . .. 114-115 Rico-Dunton rlgion, Colo., geologic features
of.. ... ...... ..... : .. .... . ...... 11()..111 Roaring Creek, N.C., magnetite deposit on.. 253 Robinson mine, Colo., nature and alteration
oC ores in ..... .. ............... 101-104 Rockingham County, N . C., magnetic ore
from............................. 258. Roebling, Col. Washington A., acknowledg·
ment to........ ................. 281 Rosebud mine, Colo., downward enrichment
in ... .. . .... . .. . ........ ·.. ....... 126 location and development of. .....•.... 124-125 primary mineralization in. . . . . . • . . • . . . . . 125 waters and gases in . . ....... . ....•..... 125-126
Ross, Clarenee S., Miser, H ugh D., a:nd, Dis· mond·bearing peridotite in Pike County, Ark .......... ..•••.. .. 279-322
Miser, Hugh D., and, Peridotite dikes in Scott County, Ark ............. 271-278
Ruby silver, in the MonteCristomine, Arlz. 13~141 Ruby Trust tunnel, near Telluride, Colo.,
ores ol.... ..... . .. .. .... . .. .. .... 78 Rutile, presence of, in titan!Cerouslron ores. 258-259
s. SanJuan Mountains, Colo., scope of report on. 65
silver enrichment ln ............... ..... 65-129 Savage mine, N. C., description of.......... 175
mammillary ore in, plate showing.... . . . 164 Schaller, W. T ., cited..................... ... 320 Section 6 hematite deposits, N. C., descrip-
tion of . . .... ...... .. . ... . ... .,. 174-175
336 INDEX.
Page. Shaw mine, N. C., magnetic ore of.. ...... 257-258 Sierra Nevada mine, Comstock lode, Nev.,
microscopic details of ore from... 52 Silver, native, ores near Wickenburg, Ariz .. 131-155 SU ver bicarbonate, experiments in preclpi·
tating metalllc sll ver from, by niccolite, smaltite, etc. . . . . . . . . . . 1~2-154
Smith, F. M., operations of,in borox...... .. 34 Smuggler-Almont mine, Colo., downward
enrichment in ................. 12Z-124 location and development or ......... ,. 120-121 primary mineralization in ....•........ 121, 122
Smuggler-Union mine, Colo., ores and waters or. ........ ................. ... .. 83-89
South Africa, comparison of diamond-benring rocks of, with those of Ar· kansas ........... . . ............ 31~16
dikea and sills or kimberlite in........ .. 313 material in the vents in.. . ............ . . . 313 petrography or the kimberlite in.. . ...... 314 pipes or kimberlite in .•................ 312-313
Southam Iron Mining Co., hematite deposit · opened by....................... 186 hematite deposit opened by, plates
showing. . . . . . . . . . . . . . . . . . . . . . . . . 165 Springs, hot, near Ouray, Colo., composition
and origin or waters from ........ 6Hi9 Stromeyerite, replacement of other minerals
by ......... ... : ........ 100,103-104,109 Suddeth, A. E., property ol, near Peachtree,
N. C., hematite on............... 198 Swan, G. W., hematite property of, ncar
Andrews, N.C ..... .. .. ·.. • . . .... 188
T. Tatham Creek, N. C., hematite Jnincs and
deposits. on ................. : .. 1!)0-192 Teegarden mine, Tenn., location and ore
vein or.. .. ...... . ......... . . ... 228, 229 Tellurld&-Ouray region, Colo., geologic feat-
ures or ..... ... . •..•..... : •.•.... . ~7 origin and enrichment of ores in .•.••. . .. 92-97
Temperatures, underground, on the Com-stock lode, Nov.. .. ............. 58
Tcnnelina, N. C., brown hematite deposits at ................. . ........... 183-166
Tennessee, ea!;tem, magnetite ores in ...... 200-270 Terrace deposits, nature o!, in Pike County,
Ark .................... · ... 292,294-295 Thayer, Ezra, acknowledgment to....... ... . 131 Titanitun,.Ores containing, in North Carolina
250-261 Tonopah, Nev., composition diagrams of
mine waters from ............. 61, 62, 69
Page. Trinity formation, nature and occurrence of,
In Pike County, Ark ........... 290-291 Tufl from Arkansas mine, micrographic plate
showing.. ..... .................. 297 Tuscarora belt, N.C., ores of.. ............. 25&-256
u. Union Consolidated mine, Comstock lode,
Nov., analyses of water !rom .. 59,61,69 microscopic details of ore from .. .. . . ..• -.. 52
Ute vein, Rico, Colo., ore minerals from "contact" above ........... .... 115-116
v. Valley River, N.C., brown hematite deposits
between Marble and ...... .. ... 180-185 brown hematite deposits soutbca.st or .. 185-187
Valley River hematite bolt, deposits and mines in ....................... 174-193
general features of. ....... ............. 168-170 reservesin . ....... . ... ... ..... ....... :. 193-194
Vanadium, absence of, from . tltaniferous magnetites o! North Carolina and Tennessee ..................... 259-260
Virginlus vein in Revenue tunnel, Colo., ores or. ............................... 75-76
Von Rlchthofen, study of tho Comstock lode by ... . ......... ................. . 42,43
w. Wagner,P.A.,cited .... . ... ... . ........... 312-JH Walker, J. W., hematit_e property, N • . C.,
description or ............•..... 191-192 Walker, Lena, hematite mine, N.C., opera-
tion of........................... 187 Washburn place, near Andrews, N. C.,
hematite deposit on .... . ....... 192-193 Wedge mine, Ouray, Colo., orcs of ...... .. 70, 72-73 Welch mine, N.C., description of.... ... . .... 179 Wickenburg, Ariz., primary native-silver ores
near ........... : ............... 131-165 Wilder mine, Tenn., location and ore vein
of.. ............................ 228,229 Williams, J. F., cited.................... .... 310 Willis, Boney, cited. . .. . . . .. .. . .. • .. .. . .. . .. 239 Wilson, N. E., analyses by ............... ·. : . 59-00
Y.
Yancey County, N. C., titaniferous magn&-tites in.. . . . . .. .. .. . . . .. .. . .. .. .. 253
Yankee Boy mine, near Telluride, Colo., ores · of.. ... . . ....... .................. .76-78
Yankee Girl mine, Colo., nature and altera-tion of ores in ................... 9!1-104
Yellow Ridge mine, N.C., orosof .......... 238-239
DEPARTMENT OF THE INTERIOR ALBERT B. FALL, Secretary
.UNtTED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, Director
Bulletin 735
CONTRIBUTIONS TO ECONOMIC GEOLOGY (SHORT PAPERS AND PRELIMINARY REPORTS)
1922
:PART I.-METALS AND NONMETALS EXCEPT FUELS
F. L. RANSOME, G. R. MANSFIELD, AND E. F. BURCHARD GEOLOGISTS IN CHARGE
WASHINGTON GOVER'NME NT PRINTING OFFIOE
1923
CONTENTS.
[The letters In parentheses preceding the .titles are those used to designate the papers for advance publication.)
Page. Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~~ (A) The Candelaria. silver district, Nev., by Adolph Knopf (published Jan.
20, 1922)............ .... ..... ... . . . ... .. . . . . . . . . .. . . . . . . . . . . . . . . . . 1 (B) Colemanitein Clark County, Nev., by L. F. Noble (published Feb. 23, 1922) 23 (C) Bonanza. ores of the Comstock lode, Virginia. City, Nev., by E . S. Bastin
(published Mar. 29, 1922). .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 (D) Silver enrichment in the San Juan Mountains, Colo., by E. S. Bastin
(published June 30, 1922).:... .... ... .... . ............ .......... .. . .. 65 (E ) Primary native-silver ores near Wickenburg, Ariz., and their bearing on
.the genesis of the silver ores of Cobalt, Ontario, by E.· S. Bastin (pub·lisbed Aug. 2, 1922) •••. . .. . . . .................... . ~ ......... . ....... 131
(F) Geneml features of the brown hematite ores of western North Carolina, by W. S. Bayley (published Oct. 17, 1922) . ........ .............. -......... 157
(G) Geneml features of the magnetite ores of western North Carolina and east-ern TenneBBee, by W. S. Bayley (published Dec. 8, 1922)..... ....... .. . 209
(H) Peridotite dikes in Scott County, Ark., by H . D. Miser and C. S. RoBS (published Dec. 22, 1922) .··:............................ . . . ...... . ... 271
(I ) Diamond-bearing peridotite in Pike County, Ark., by H . D. Miser and C. S. Rose (published April 25, 1923) .... .. .. .. .. .. .. . .. .. .. .. . . . . . .. . 279
(J) The Los Burros district, Monterey County, Calif., by J. M. Hill (pub-lished A_pril 28, 1923) .. .. .. .. .. . ... :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Index. .. ..... .. ................... ..... ...... ....... . .............. . ... . . 331
ILLUSTRATIONs·.
PLATE I . Typical exposures of limestone member of Horse Spring formation in Clark County, Nev.: A, Near Horse Spring; B, Near Bitter Spring. 28
II. Colemanite deposit near Callville Wash, Nev. : A, Looking east along outcrop of colemanite bed; B, Looking west along outcrop of cole-manite bed .... .. . ... ......... ...... ....... ......... . ..... .... 29
III. "Goose egg" structure in limestone beds associated with colemanite deposit near Callville Wash, Nev.. ..... ............ . . .......... 38
IV. Geologic map of Nottely-Va.lley River belt, N. C., showing location of principal ore deposits. . . . .. . . . .. . . . .. .. . . . . . . . . . . .. . . . . . . . . . 162
V. Views in brown-hematite Inines in western North Carolina: A, View in Heaton & Russell Inine, near Maltby; B , Hydraulic jet in Heaton & Russell Inine; C, Hayes-Hoblitzell mine, near Marble; D, Mam-Inillary ore in Savage mine, near Murphy ... -. . .. . . . . . . . . . . . . . . . 164
VI. Views in brown-hematite mines in western North Carolina: A, Ore bed in mine of Southern Iron Mining Co., near Andrews; B, West end of bed shown in A, showing parallelism with surface; ' C, Geneml view of·bed shown in A; D, Ore vein in Heaton & RuBBell Inine, near Maltby. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
III
IV CONTENTS.
Page.
PLATE VII. A, B, Photomicrographs of peridotite dike near Olio, Scott County, Ark .• •. . ••.. . ..... . ......... •.••. ••. . •...... -- •.. . - . . . . • • . . 276
VIII. Geologic map of parts of Pike, Howard, and Hempstead counties, · in southwestern Arkansas. . ................. ........ .... .. .... 280
IX . Geologic map of the Prairie Creek area of peridotite in T . 8 S., R. 25 W., 2~ miles south-southeast of Murfreesboro, Pike County, Ark • . . . .. .... .... . ....... ..... .... . ..... . · ··· ·········· ·· ·· 280
X. A, Exposures of the hypabyssal intrusive peridotite (' ~hardebank ' ') in the nqrthe.rn part of the Mauney mine, near Murfreesboro, Ark.; B, View looking north across the large open cut of the Mauney mine, near lv[urfreesboro, Ark............ . . ... ....... 296
XI . A, Altered volcanic breccia (" blue ground ") in cut of Ozark mine, near Murfreesboro, Ark.; B, Ozark mine and washing plant, near Murfreesboro, Ark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
XII. A, Photomicrograph of nearly fresh hypabyssal intrusive peridotite (" hardeliank"), Prairie Creek area of peridotite, near Murfreesboro, Ark.; B, Photomicrog~ph of hypabyssal intrusive perido-. tite (" hardebank") from summit of Middle Hill, in the area .of peridotite n~ar Prairie Creek, Murfreesboro, Ark..... . ...... . .• 296
XIII. A, Photo.ui,icrograph of blue-gray tuff from drill hole No. 3 near Arkansas . mine, near Murfreesboro, Ark.; B, Photograph of polished surface of volcanic breccia (" blue ground ") from southern part of Mauney mine, near Murfreesboro, Ark...... . . . 297
XIV. Maps showing the disti-ibution of the peridotite at the American and Kimberlite mines and at Black Lick, Ark. . . . .... ..... .. ... . .... 304
XV. A, Diamonds from the Arkansas mine, Pike County, Ark.; B, . Trenches on the Kimberlite mine, near Murfreesboro, Ark ..... ; 320
FIGURE 1. Index map showing t he location of the Candelaria district, Nev.... 2 2. Columnar section of the Tertiary rocks of the Candelaria district,
Nev.. . . . ... ....... . ...................... ... . . ............ ... 9 3. Map showing location of colemanite deposits in Clark County, Nev.. 24 4. Diagrammatic sketch showing mode of occurrence of colemanite
deposit near Callville Was)l, Clark County, Nev.... .... . . .. . . ... 36 5. Argentite occupying a similar interstitial position to galena with
respect to quartz and sphalerite, in bonanza ore from 1,650-foot level of C. & C. mine, Comstock lode, Nev ............ .... :... . . 48
6. Primary argentite and gold (electrum?) in bonanza ore from 1,650-foot level of C. & C. mine, Comstock lode. .. ... . . . .. .. ..... .. . . 49
7. Bonanza ore from C. & C. mine, Comstock lode, East vein, between 2,000 and 2,050 foot levels, carrying abundant primary argentite associated with galena, sphalerite, chalcopyrite, quartz, and gold 50
8. Polybasite, probably primacy, intergrown with galena, sphalerite, ' chalcopyrite, and quartz in ore from C. & C. mine, Comstock lode, East vein, 2,200-foot level.. ...... .. ... . .. . . .. . . .. ..... . ... ... . . 51
9. Primary (?) argentite in small quartz-lined vug peripherally replaced by native silver in shallow ore from Belcher bonanza, Comstock lode...... ... ....... . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . 53
10. Detail, under higher magnification, of the exceedingly irregular replacement boundary between native silver and argentite in the specimen from which figure 9 was drawn..... ... .. ... ... ....... 54
11. Polybaaite peripherally replacing primary argentite in shallow ore from the Belcher bonanza, Comstock lode. . . • . . . . . . . . . . . . . . . . . . 55
12. Composition diagrams of hot ascending waters from Comstock lode and Tonopah, Nev., and from Ouray, Colo • .. •• . .• :........... 61
CONTENTS.
' FIGURE 13. Composition diagrams of cool descending mine waters from Comstock lode anP, To~opah, Nev., and from Red Mountain, Colo . .
14. Composition diagra.ma of thermal spring waters from Ouray, Colo., and somewhat similar mine waters from Virginia City and T()nopah, Nev ..... . ... . ..... ... . ... . .. . .. · .... . .. .. ........ .
15, Ore showing primary pearceite intergroWn. with tetrahedrite, . chalcopyrite, and "galena., Bachelor mine, Ouray, Colo .. ... ... .
16. Primary intergrowth of proustite, galena, quartz, and sphalerite, in ore from Yankee Boy mine, between Ouray and Telluride, Colo . . ..... .. .... ... .. . .. . ........... ........... .... .. .. .. .
17. Irregular. intergrowth, apparently primary, of tennantite and proustite, Humboldt mine, between Ouray and Telluride, Colo.
18. Irregular intergrowth, apparently primary, of galena, quartz, and proustite, Humboldt mine, between Ouray and Telluride, Colo.
19. Primary veinlet of quartz and proustite traversing sphalerite, Humboldt mine, between Ouray and Telluride, Colo ........ ..
20. Primary intergrowth of quartz, sphalerite, galena, wnnantite, proustite, pyrite, and gold, Smuggler-Union mine, Telluride, Colo ....... ...... ....... .. .. . . ..... . . .... . ... : . . ..... . . .. ..
21. Late primary veinlet of .quartz and proustite traversing sphalerite, Smuggler-Union mine, Telluride, Colo .. . ................... .
22. Ore showing primary pearceite intergrown with tetrahedrite, chalcopyrite, and sphalerite, Waters vein, Liberty .Bell mine, Telluride, Colo ..... . ...................... . . . .. . . ; ..... , . . .
23. Replacement of' galena by argentite, showing an apparently intermediate mineral , Waters vein, Liberty Bell mine,· Telluride, Colo . . . ........ .... ........ .... .......................... . .
24: Replacement velnleta of stromey"erite in sphalerite, Yanke~ Girl mine, Red Mountain, Colo .. . . ........... ...... , .......... ..
25. Probable replacement remnants of galena and tennantite (?) in secondary stromeyerite, Yankee Girl mine, Red Mountain, Colo . .
26. St.romeyerite as a pseudomorphic replacement of bournonite (?), Yankee Girl mine, Red Mountain, Colo ....... .. ........ .. ... .
27. Diagram showing what minerals have replaced otheis in the ores of the Yankee Girl mine, Red Mountain, Colo ......... .... ... .
28. Replacement veins of covellite in enargite, Genesee mine, Red ·Mountain, Colo .................. . ....... . ....... . ..•........
29. Composition. diagrams of mine waters from Genesee mine, Red · · Mountain, Colo., and of waters of similar quality from Ducktown,
Tenn., and Butte, Mont ............. .... ... . ............... . . 30. ComPosition diagrams of waters from Emma mine, "Soda Spring,"
and Rosebud mine, Dunton, Colo ................ . . · ....... .. 31. Primary argentite in sphalerite, Smuggler-Almont mine, Dunton,
Colo . .... ... . .. . . .. ... . ... .. . ............. . . . . . .......• . ... . 32. Primary polybasite or pearceite irregularly intergrown wif4 pyrite,
sphalerite, and chalcopyrite, Smuggler-Almont mine, Dunton, Colo . ............................ . . . . . ....... : ... · · ··· ·· · · ·
33. Characteristic relations of niccolite; chloanthite, and calcite, Monte Cristo mine, near Wickenburg, Ariz .. ... . ... .... , • .. .. .. .
34. Pri.xnMy intergrowth of niccolite, native silver, and chloanthite, Monte criato mine, near Wickenburg, Ariz ... . . . ... . .. .. . ... : ..
35. Primary nativ,e silver forming branching crystals enveloped by chloanthite, Moute Cristo mine, ncar Wickenburg, Ariz .... . .. .
v Page.
62
69
77
80
81
82
85
86
90
91
100
101
102
103
106
107
118
122
123
135
136
137
VI CONTENTS.
Page. FIGURE 36. Drawing on a larger sca.le of a portion of the specimen shown in
:figure 85.. . ............................. . ...... . ... . . .... ... 138 37. Irregular primary intergrowths of native silver, chalcopyrite,
chloanthite, and quartz, Monte Cristo mine, near Wickenburg, Ariz . .. . . ......... . . ..... .. ........ ........ . . .. ... .. ....... 139
38. Irregular primary intergrowth of proustite, tennantite, and calcite, Monte Cristo mine, near Wickenburg, Ariz .. ·... . ..... ..... ..... 140
39. Primary association of proustite, tennantite, calcite, and quartz, Monte Cristo mine, near Wickenburg, Ariz........ . . ..... ... . .. 14.1
40. Primary intergrowth of proustite, tennantite, qunrtz, and gere· dorfite, Monte Cristo mine, near Wickenburg, Ariz.............. 142
· 41. Association of niccolite, chloanthite, and native silver which has been fractured and argentite nnd calcite deposited in the fractures, probably as late primary minerals, Monte Cristo mine, near Wickenburg, Ariz....... .. ..... . .......... . .. . . . .... . . .. 143
42. Replacement of native silver by argentite, Monte Cristo mine, ncnr Wickenburg, Ariz. ..... . .... .. . . . . ........ .. ... .. .. ... .. 144
43. Part of a "nest" of niccolite withln smaltite, Kerr Lake mine, Cobalt, Ontario.................................... . . ...... .. 148
44. " Nest" of niccolite and silver within smaltite, Kerr Lake mine, Cobalt, Ontario........... . .................................. 149
45. View on larger scale of a part of a "nest" of silver in smaltite simi-lar to that shown in :figure 44, Kerr Lake mine, Cobalt, Ontario. 150
46. Veinlets of calcite and native silver traversing niccolite, Kerr Lake mine, Cobalt, Ontario ........... :............ . ......... 152
47. Index map of western North Carolina showing location of areas containing valuable deposits of brown hematite ore.. . ... . . . ... 159
48. Geologic map of area containing deposits of brown hematite at Tennelina, near Hot Springs, N. C. . . .. .. .. .. .. . .. . . . . . .. . . .. 164
49. Diagrammatic north-south section through area shown in figure 48. 165 50. Northwest-southeast section across Nottely River hematite belt at
Culberson, N. C................ . ................ . .......... . 168 51. Northwest-southeast section across Valley River hematite belt
near Marble, N.C.... .. ...................................... 169 52. Diagrammatic cross section through Fain-Hitchcock mine, near
Murphy, N. C.... .. .. .. ..... . ........ . .. .. ................ .. 173 53. Section across end of pit on J . W. Walker property, near Andrews,
N.C........................ . .... .. . .. .. . . .. . ............... 191 54. Geologic map of the Peachtree area and the eastern part of the
· Brasstown belt, N.C........................................ 195 55. Section across Brasstown belt, Peachtree area, and Valley River
belt near Regal, N. C. . . . .. . .. . .. . .. .. .. .. .. .. .. . .. .. .. .. .. . 196 56. ·Map of Martin Creek area and Hiwassee-Nottely River belt, N: C.,
showing location of deposits of brown hematite. ....... . . . . . . . . . 199 57. Index map of portions of North Carolina and Tennessee showing
· position of areas covered by :figures 58-61. . . . . . . • . . . . . . . . . . . . . 210 58. Map showing principal mines and prospects on and near the Cran-
berry belt, in A very and Mitchell counties, N. C., and Carter County, Tenn........... . ... . ....... .. . .. ...... . ...... ..... 215
59. Map showing principal iron-ore prospects in Ashe County, N. C.. 216 60. Map showing location of principal iron-ore deposits in Catawba,
Lincoln, and Gaston counties, N. C. . . .. .. .. .. .. . .. .. . .. .. .. . 232
CONTENTS. VII
Page. FrGURB Gl. Map shoWing location of prospects between Shell Creek and Butler,
Tenn. , and in adjacent portion of North Carolina ....... . _._._._ 263 62. Diagrailli!lll.tic north-south section through Finney & ·Teegarden
mine, in valley of Lunsford Branch, Carter County, Tenn._.. .. 266 63. Map showing location of peridotite in Scott County, Ark. ___ ____ . 272 64. Sketch geologic map of a part of sees. 3 and 4, T. 3 N., R. 26 W.,
in the valley of· Dutch Creek, Scott County, Ark., showing the occurrences of peridotite .. _ . ___ , ..... . ...... _ .......... _ . _ 273
65. Map of parts of ArkaD.Sll8, Oklahoma, and adjacent States, showing the area that contains the diamond-bearing peridotite of Pike County, Ark .............. ...... _......... . . . . . . . ........... 279
66. Section of dike o'f weathered peridotite cutting the clay of the ' Trinity formation at the Kimberlite mine, Pike County, Ark.. 305
67. Structure section through the American mine, Pike County, Ark., illustrating the relations of the peridotite to the Trinity and Bingen formations .. _ . ... . . . ... _. _. _ . . . . .. ..... .... ;....... . 308
CONTRIBUTIONS To· ECONOMIC GEOLOGY; 1922.
PART 1. METALS AND NONMETALS EXCEPT FUELS ..
F . L. RANSOME, G. R. MANsFIELD, and E. F. BURCHARD, Geologists in charge.
INTRODUCTION.
The Survey's "Contributions to economic geology" have been published annually since 1902. In 1906 the increase in the number of papers coming under t~ classification made it necessary to divide the contributions into two parts, one including papers on metals and nonmetals except fuels and the other including papers on mineral fuels. In 1915 the year included in the title was changed from the year in which the field work reported in these papers was done to the year of publication, and in consequence there was no volume entitled "Contributions to economic geology, 1914." The subjoined table gives a summary of these bulletins.
United States Geological Survey "Contributions to economic geology."
Date in title.
1902 •.. ••••. •. •.•. . .• . .. • . . ... 1903 •• • •• •• •·•• •••• •••· • · ••.. • 1904 •.••• •• • . • : ••.• . .• .• . • .•. . 1905 • • •••••••.•••• • .•.. ••• .••. 1906, Part I. .. .. ...... .. . .. . . .
Part II .. .. .. .. . ........ . 1907, Part I. . .. . .. .. ........ . .
Part II .. . ... . . .. ..... .. .
1908, ~:~~k::: ::::::::::::-:: 1909 Partl. •. , . .. . •..........
'Part I I.. : . ..... . .... -··. 1910, Part! ...•.. . .. . . ........
Part II. ....•.•.. . ....•..
1911, ~:~h:: :::::::::::::::: 1912, Part L .. . .... . . .... .... .
Partll •.••..•......... . .
Date of pnbllca
tion.a
1903 1904 1905 1906 1907 1907 1908 1909 1909 1910 1910 1911 1911 1912 1913 1913 1914 1914
Bulletin No. Date in title.
213 1913, Part I. .. ............... . 225 Part II. . . . . .. ..... • .. .. . 260 1915, Part!. ..... . ... . . .. .••.. 285 Part II. ..•.. . ... . ..... .. 315 1916, Part I. ... ...... . .. .. .. . . 316 PartiL . ... ..• . . . . .. . ... 340 1917,Partl. ••................ 341 Part!!. • ... . .. .. . . .. .. . . 380 1918, Part!. ..• •. •.. . ....•.... 381 Partll . . .. . ... . . ... . .. . . 430 1919, Part I. .... . .. .. . .. .. .. . . 431 Partll .. .... .. . .. ..... . . 470 1920, Part I. ....... . . . . . ... . . . 471 Part II .... .. . .. . ....•..• 530 1921, Part!. .••. .• ••.. .•. . . .. . 531 Partll. . . . .• .. • ..• .. . •. • 540 1922, Part L ............ ... . . . 541 Part II .. ... . ...•. .•.. .• •
Dat~ of Bulletin P~~~~- No.
1915 1915 1916 1916 1917 1917 1918 1918 19la 1919 1920 1920 1921 1921 1922 1922 1923 1923
580 581 620 621 640 641 660 661 690 691 710 711 715 716 725 726 735 736
"The date given i s that of the complete volume; beginning with Bulletin 285, the papers have been issued as advance chapters as soon as they were ready.
IX
X CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1922, PART I.
As the subtitle indicates, most of the papers in these volumes are of three classes-(1) short papers describing as thoroughly as conditions will permit areas or deposits on which no other report is likely to be prepared; (2) brief notes on mining districts or econm:p.ic deposits whose examination has been merely incidental to other work; and ~) preliminary reports on economic investigations the results of which are to be published later in more detail~d form. Al~hough these papers set forth mainly the practical results of
economic investigations they include brief theoretical discussions and summary statements of conclusions if these appear to require prompt publieation. - · ·
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