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<br />196 GEOLOGY AND ORE DEPOSITS OF THE FRONT RANGE, COLORAno
<br />seems evident that sulfide ntiueralicltiou preceded, ac-
<br />camnanied, and follo+red the intrusion of the dikes.
<br />Subsequent to the intrusion of the porphyry dikes anti
<br />their associated sulfides, the rocks in the vicinity were
<br />broken by numerous fractures and faults, ',which dis-
<br />place the ore-bearing dikes in many places. In gen-
<br />eral the faults ale not mineralized, though some are
<br />quartz-&Ited noel bordered bI• nan•orv leached zones. In
<br />one place narrow seams of calcite and quartz cut both
<br />[like and fault. One fracture plane in the schist on the
<br />tunnel level shower] about an inch of quartz rind cal-
<br />cite with a little chalcopyrite.
<br />Ore shipped from this mine is said to average about 3
<br />percent of copper an[I 0:30 owtce of gold and a few
<br />ounces of silver per ton. Its distribution, however, is
<br />sporadic, and, except for the chamber stope on the
<br />tunnel level, no large bodies hale been found. Only a
<br />few carloads of ore hate been shipped.
<br />OTHER .12INSS
<br />Data on other mines are givetl briefly below. Detailed
<br />descriptions have been given b}' Bastin and $ill?
<br />A17NIE 8
<br />Dccclopmcn t.-Two shnfts, 300 and 2'?6 feet deep, 310 feet
<br />apart; tunnel 672 feet long Joins simCts 166 feet belorv surface.
<br />Vein.-Annie H.: Strike, N. GO° E. ;dip, 30°-:A° N.
<br />Ore and sulfide nli+lcru la.-pyrite and gold.
<br />Tenor.--0.2 to 2.6 ounces of gold per ton; most assays show
<br />0.80 to 1.0 ounce. Soine picked lots of ore essayed 0 percent
<br />of Copper..
<br />GOLD DIET
<br />Devclapnicrlt-Disco+'ered 1860. Drift tunnel and several
<br />shafts; main shaft several bond red feet deep.
<br />Producliori.-October 1, 1866, [u .Innnn n• 6, 1561, $11,52Q94;
<br />equals one-sixth of the total prixluclion,
<br />{"efll.-Gold Dirt: Strike, N. SO•-Si° E.; dip, S(1°-85° S.;
<br />width, 8 inches. Posttnineral movement has crushed mid sheared
<br />ore in places.
<br />Ore and sulfide minerals,-Pyrite And gold.
<br />L'krnlycs rdlA dcprJi. are oxidized near .carfare and richer
<br />than in depth. Ore below oxidized zone asernged O.CS ounce
<br />of gold per ton far concentrating ore and 1.0 to 3.0 ounces OL
<br />gold for smelting.
<br />ING$dM
<br />Development.-Shaft 270 feet deep and hinnel 120 feet long.
<br />R~aductiori.-To 1912, $10,000.
<br />1'ein.-Ingram: Strike, N. GS• E.; dip, iG° N1V. Vein cuts
<br />foliation of granite gneiss at acute angle.
<br />li'¢!f rock.--Granite gneiss.
<br />Ore and sulfide minerals.--Chiefly chalcopyrite and pyrite,
<br />some galena and gold.
<br />O¢upue minerals,-Quartz.
<br />Tenor.-14 to 20 percent of copper.
<br />PEHIGO
<br />Developmenl.-Two tunnels and screen] old shnfts.
<br />Veir4s.-Saker, Daisy, Ladysmith, and Perigo: I+tostly trend
<br />east to uor[hexst; wmplicated set of veins; 2tF_~ to 6 feet wide.
<br />Ba.~nn, E. S., end HIII, 7. ai., op, clr., pp. 184-205.
<br />Tuw;uel euuthwest, br:umhes unite tv form slugle fracture zone,
<br />uM very strong rum heavily miuentlized. Veins consist of dis-
<br />seminations of pyrite iu wall rack :dung ft'uc[ure zuues. Localle
<br />are occurs in sharp-walled ceinlets. •
<br />li'al! roch.-Schist, granite gneiss, and pegmatite.
<br />Ore wad auifWe minerals -Pyrite antl gold, some galena.
<br />Caapue minerula.-1Cn11 rock.
<br />Tenor.--12 tons of ore shipped from 1901 to 1969 coutntued
<br />0.4-k to 3.1G ounces of gold (average 1.23) and 1.20 to 4.70 ounces
<br />of silver per [on.
<br />BI/IIGGLE$
<br />Devclopmcuf.-Drift tunnel .9i feet long; shaft 160 fee[ deep.
<br />Productiwr -Total [0 1012, bet+reea $50,000 and gi5,000.
<br />1'cin.-Smuggler: Strike, \. 75° E.: dip G6° N.; r:mges from
<br />small barren fracture to 8 fee[ in width and averages ^ m' 3
<br />feet. t\'tder parts of vein consist o[ crushed n•nll rock cartaln-
<br />ing lenses and disseminated pyrite.
<br />11'all rock.-Schist o[ the Idaho SDriugs [onna[ion, coo tiiaiug
<br />small tongues of granite gneiss.
<br />Orc and sulfide minerals-P}•rite and some hematite.
<br />Omipue mirlerala.--Cherry silica and sideri[e.
<br />Ore saoota.-l+iineralizetion stt•ong throughout most of the
<br />tunnel; hlrges[ ore Wdy •xj0 feet in scope Icug[h, S(i feet high,
<br />nreruges 4 feet in Oiickness.
<br />Tenor.-General run o[ mine ore averaged 0.5 ounce of gold
<br />per ton. 1910: Avernge concrnU•ntes Bald lu smelter cvm[ained
<br />0.7v ounce of gald per ton. 1[111: Acm~nge coneentnttes con-
<br />titlliefl 1 UllllCe Of gold nnJ 1 aunce Uf All Cl•I' hel' IUII. Caat•51'
<br />p}rite cnutulu.c 0.1 nnnm of gold Per tan.
<br />WAE EAGLE
<br />Dcuc/npmrn 1.-Simft "_W feet drop +rlth short drifLC on thrr°
<br />levels.
<br />Vcina.-R'nr Eagle: Strike, N. G[1• E. Vein material on dump
<br />is pyrite-impregnated cotmtry ruck ten versed by velus of coarse
<br />grained pyrite with Iitttn quartz, as umch ns Pyy inches wide.
<br />II'all crock.-CrnnlCe gneiss.
<br />Or-e and sulfide minerals.-I°yritr and gold, .come speculurin
<br />:wd chalcopyrite.
<br />Umipne miners l~-Qnnttz.
<br />Team:-Avernge 0.76 ounce of gold DPI' ton.
<br />£LDORA DISTRICT
<br />The Eldora district covers a few square miles in th~
<br />vicinity of Eldora, about 3 miles west of Nederland. e1
<br />defined here, the disu'ict includes [he mines near Lo=
<br />Lake and southwest of Grand Island as well as rhos
<br />south of the town (pl. 3). It ]tax had only a small oul
<br />put and is of interest chiefly because of its gold-tellurid
<br />ores, which were diswvered about 18JG, The deposit
<br />were actively developed during the following decade, bu
<br />since 190G the camp has been comparatively inactive
<br />The only mine credited with a noteworthy output is th
<br />Enterprise, about half a mile south of Eldora.
<br />The chief rocks of rite district are biotite schist an
<br />quartz•biotite schist of the Idaho Springs formatic
<br />and hoenblende monzonite porphyry. Granite gnei
<br />related to file Boulder Ctreek granite occurs in irregul;
<br />masses, mostly to the north and to the south of file di
<br />trier, and there is a lens of gt•allite gneiss just soutllwe
<br />of Eldora. In the western part of the district, aboi
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