') I

702 Woodlark Building Portland,

GLASS BUTTES PROSPECT, NORTHEASTERN LAKE COUNTY, OREGON

The Glass Buttes prospect is on the isolated hills of that name in the northeast part of Lake County, Oregon. It is about 3.5 miles by road eouth of the highway between Bend and Burns, in Tps. 23 and 24 s., R. 23 E. (pl. 6), The propert; ie owned by Charles I. lliller, of Bend, Oregon., and comprieee 48 claims, as shown on plate 8. QuicksilTer bas been known tor aeTeral ,:.ears- to occur here.j/ Test pits and short tunnels a.re scattered oTer the property, but so tar there haa been no production. The pa.rt of the Miller property from lo. 1 tunnel to about 21 000 feet to the north was Tisited by the writer August 23, 1940,

Accerding to Waters,.W the buttes are COllpoted of three aroupa of lan .flow ■, The highest and lowest of these il"OUpl are baaaltic. The interaediate group, which ia ■ore than 400 feet thick and form■ the greater part of the Glaaa Buttes, includes daeite and seTera.l. other kinda of andeaite, as well a1 perlite, , and Titropey-re. Only these gla11y lans are upo•ed at the quicksilTer prospects. According to Wa.ters1 the Toleanic rocks of' the Glass Butte, form a broad anticline broken by aany iarul f'aul ts of diTerse trend1 and magnitude.

The property-, which has an area of' about 1.5 square miles, i8 tmderlain 'b7 laTa that originally consisted almost exclusively of flow-banded glass. This laTa has been extensi'vely opalised along broad zone• of northwesterly trend that extend be7ond the limits of the area shown on plate 8. Hallo7aite, a cla1 mineral, ia mixed with the opal, locally in some abliadance. Cracks and holes in the opaline I / material are lined with fine-grained quartz, Other and presumably later cracks are lined with cinna.bar grains. The opaline material locally has horizontal bands tha:t may represent the flow bands of the lav:! which it has replaced. Moat of the pits and other excavations seen by the writer show cinnabar but generally in very email amounts. The cinnabar darkens on exposure, and it can therefore be detected only by chipping the surface of the opaJ.ine material.

In several places the opaline material is broken by fractures and breccia zones that a.re comparatively rich in cinnabar. These trendclf. 55o - 65° 1'. and moat of them dip rather steeply northeastward, though a few 4ip toward the south­ west. The largest ones thus far exposed - in lo. 1 tunnel and in the bottom of a 4.3-foot shaft 850 feet northeast of the portal of that tunnel - are 2 to 5 feet wide and have been followed only short distances a.long the strike. The quicksilver content of a few representatiTe aamples is ehown on plate 8. The samples designated by G. o. and a number were taken by the writerJ the others were furnished by Jlr. Miller, who also reports two samples not recorded on plate 8. One ot these, from a •broken zone• l foot wide, contained 0,675 percent of quicksilver; the other, trom a •brecciated seam,• contained 0.550 percent of' ~cksilTer. Sample G.0,2, from the botto■ of the 44-foot shaft, contained

j/ Schuette, C. I., QuicksilTer in Oregonz Bull. 4, State or Oregon, Department of Geology and Mineral Industries, p, 168, 19.38. !/ Watere, Aaron, A Structural and petrographic etudy of the Glass Buttes, Lake Oount;y, Oregon; Jour. Geology., vol, 35, No. 5. PP• 441-452, 1927. 702 Woodlark Building Portland, Oregon

0.10 percent of mercuri c chloride. As the total amount of quicksilTer in thl• sample was only 0.22 percent, a large proportion of the metal was present as chloride, and this m,q be true of other parts of the deposit. Thia poasibility should be taken into account in planning the reduction plot, and other euple1 ahould be tested for chl.1t111de. On the other hand, auple G.O. 7, which i1 from a comparatiTely rich band 2 feet wide in lo. 1 tunnel, yielded only O.OS percent of aercuric chloride. This sample contained o.68 percent ot quicksilver. The aasaya, together with observations on the ground, indicate that the quickailTer content of the opalized material ranges fro• a trace to about 15 pounde to the ton. Most of the 88llples recorded on plate Sare from the richer parts of the deposit, so that the aaaays probably do not fairly represent the average tenor. It eeems iaprob&ble that aore than a •mall part of the deposit col1l.d 'be mined profitably at the prices that prevail under noraaal circumstances, but as the deposit is very large and certainly contains some fairly rich ore, further work 11&1 ahow that it could serve as a 1ource of ¢cksllver under eaergency conditiona. · \

'Refs U.S.G.S. Bulletin lo. 931-B "Some Quicksilver Deposits in Adjacent Parts of levada, C s.l.ifornia, and Oregon. ~Cl..U-rl.lJ vzcu-c:-, CRIB MINERAL ~ESJURCES FlLE 12 RECORD IOENTlFICAllON RECORD NO••••• ••••••• M054~94 REC~RG TYPE•••••••••• Xl~ COUijTRY/ORGkNIZATJON. USGS INFJRHATlDN SOURCE ••• 12 MAP CODE ND. JF ~EC ••

R[PLi

STkTE CODE••••••••••••••• OR STLfE NA~E: JRE;DN COU~TY •• ••••••••••••••••• ORtl~A&E AiE'•••••••••••• u7)303 PACIFIC hORTHW[ST ~HYSLOGR~PHI: PRJV ••••••• H[GH ?~AINS LAhD CL~SSJFl:ATlON ••••••

~u ... u SCAL[ QUI\D NO OR ~A.ME 1: 25000(} BUl•dllS

lATlTJDE L □ "fGITUOE 1%3-31-59~ ll 9-56-30W

J TM ~J Rl Hl ~.a; UT!1 EASTING UHi 20NE NO 't C2.rt 000. 262 . 0C. +11

l..iP •••••• 0235 ~A.NGE. •••• 02lE SECTlQN •• 3ft. 1-1El,lDlAN. WILLM1E1TE YO· ACC~RACY JF LlCAllON ACCJRATE ~u~:~::;;;; p::;J~:· ;;~:~~;~~-rJ ~AJJR PRODUC TS •• HG JRE MATERIA LS ( Ml~ERlLS , RDCKS , EIC .) : CIN~t..ai\R MAI~ DRE MIN~RALSt CI NNAlH.R

E(Pl~RllID~ ,No lEI EL Cf~ENT STATUS JF ~~ 0 LJR . 0~ DEV . b PR DP~RTJ IS INACllVE YE~~ JF DISCJVERr~ • •••••• 1933 BY ~H □ M •••••••••••••••••• P. L. FORBES VEAR JF Fl~Sf PRJOUC TION . 195& YEiR □ f LAS T PRDOUCTIJN . 1968 PRt.SDH/ LASf )wllER . .... •• VER!-:E E . R'tAN, W. H. JUSfRO~I. JOHt,.' ~( MAhMANs 1963 PRE~EkT/ LASf JPE~A TOR •••• JACKiO~ MOU~ T,IN Ml~ING CO •• 1968 EXPLOR . AND JE~E~or . CBH~EN TS: OMEA C □ NJRACT ~ECO~~ENDED DE~ l ED IN 1955

OESCRlPTID~ 9F DEPJS!T DEPOSIT TYPES: MlNERALllED FA JLT l □ NES, DPALITE FOR~ / SHAPE OF DEPQS]T: SIZE / GlRECTIJNil DATA SIZE ~F DE'~Slf •••••• S~ALL

OESCRIPT131~ J F 1tOR

P"aouc r Im. VES S»~LL PRJJUC TION

CU~ULATl i E PRJOUC f ICN ( 3 RE ,CO~M )).,CaNc •• ~VERBUR .) P~JDUCflO~ YEARS ••••••• 195b - li50, 1961

SJJ~CE OF INFO~~~TlON (P~DDUCTIO~) •• ~SB~ AiO C01PANY RECORDS VJA BRCDKS, 1968 PIJOUCTIO~ CJ~iE~T~ •••• PRODUCTllN INCLUDES 119 FllSlS FROM GLASS RIDGE KINE, 3L6 FL FROM ThE RYAh GROUP AND 109 FRG~ THE PGLA~lS PRQPERTY

C □ Hr-tE.NIS lRESERV::SJ ... EST HtArEO RESERVES /.RE SHALL GEOLOGY lND ~11~RALOG AGE OF HCST RJCKS•••••••••••• 110 HOST R~L~ TYP~S•••••••••••••• JfALITE DE~lVED FR LM GLASSY SlLICIC lND llfF AGL OF ASS3C. IGNEOUS ROCKS •• ~IC lG~EOU~ RJ:K TYPES••••~•••••• ~LASSY SJLICIC LAVAS ANO TUFF PEkliNCNT MI~ERA~OGY ••••••••• JPALITE, CLAY MINERALS IKFC~TANT JRE C3~TROL/LQCUS •• 5RECCIATED ZONES I N DPALITE

GEQLJGY (~UPPLEhE~JA,t Il•F □ RMATIUN} iEGIOihL GE □ LJGY lECTONIC SEfll~G ••••••••••• JISSECTED LAVA PLATEAU LOCAL GEDLJGY ~IGNIFICANr LOCAL STRUCTURES: JP~LIZED ZONES A~E ALONG NW TR~ND ING F~ULTS $IGNIFICA~T ALTERATION: JPlLIZ&TIJK lF HJST ROCKS

CECL □ GlCtl PRD:ESSES OF CG~CE~TRAIID~ OR L~RICHHENT: HYDRGT~ER~Al SOL~TlONS

C □ H~EijJS (GEJLJGY AND HINERA LO&Y): hE PRl~ClPL~ GlE BJDIES occu~ IN AN INT~~SELY CRUSHED OPAllTE B~[CCll ~HlCH HAS BEEN RECEMENTEC SY SlLICA lND CiNN~B~K.

GENERAL REFERENC[S 1) eRJJKS, H. C., 19&;, ~UlCKSl~VE{ IN lREGCN: OREG]N DlPT. GF GE : LOGY A~D MINERAL INDUSTRIES. BULL. 55• 223 P. 2) MERCJ~Y I~ OR~GJ~, 19b5t USB~ IC 6252 3) 8RDDKSt H. L., 19&5, GLASS BJTTES tERCJRY: ODGtlI UNPUBLISHED R[PORT I) ~EEJ, G.C., 1946, EKPLOR~TlD~ OF GLASS BUTTES ~ERtURY DEPCSll, LAKL CJUNTY, ORE.: USBH RI 39 5) R □ SSs :.P., 1941, SOME ~JIC(SILVER FROS~EClS IN ADJACE~l 'JRTS GF hEYAD!, CALlfDRNIA, AND G~EGON: USGS BUL S3:-u. P. 23-3~ ' .--¼'1...-­ ~~ R. I. 3926 AUGUST 1946

UNITED STATES DEPARTMENT OF THE INTERIOR J. A. KRUG, SECRETARY

BUREAU OF MINES R. R. SAYERS, DIRECTOR

REPORT OF INVESTIGATIONS

EXPLORATION OF GLASS BUTTES MERCURY DEPOSIT

LAKE COUNTY, OREGON

Pl

BY

GLENN C . REED R.I. 3926, August 1946.

REPORT OF DNESTIGATIONS

UNITED STATES DEPARTMENT OF TEE INTERIOR - BUREAU OF MINES

EXPLORATION Of G:LASS BUTTES MERC:URY DEPOSIT, LAKE COUNTY, OREGONLJ B.y Glenr{ C. Rc·ed'Y

CONTENTS Introduction...... Pagel Acla:lovrledgm.en ts. • •••••••••••.•••••••••••••••••••••••••••• , ~ ••• • • • • • • • • 1 Bi story •••••••••••••••••••• •·• •••••••••••••••••.••••••••.••••• • ~ • • • • . • • 2 Prope1"'ty i1oldings •~• .. ...• .. • ••••••• , • , • •. , •••••· •••••.• ._ ..... ·••..• • • ~ ••••. • •• • 2 Physical features ai:td communicat'ions. ~ i ••••••.•••••••• • ••••••• •·• •••• •. 2 Labor and l;i. ving conditions •••••••••••• ~ • • • • • • • • • • • • • • • .• • • • • • • • • • • • • • • 2 Description of deposi·ts •'• •• .". :. • • • • • • • • • • • • • • • • • • • • • • • • • • •• • •.• • • • • • • • • 3 The ores•••••••••••••••••••••;~·.; •••••••••••••••••••••••••• ~...... 3 Mine worlcings • ••••••••••.••• • •••••••••••••••••.•••••••••••• • ••••• ; • • • • 4 INTROBUCTION Preliminary examination of the Glass Buttes mercury deposits, La.~e County, Oregon, was ·made in 'August 1945 at the request of H. _s. Lazier, pres­ ent lessee of the deposit.

Most of the prospect openings in the area were inspected. The more sig­ nificant workings were sampled and mapped in detail. This. r _eport presents the 'dat~ obta:LDed from the investigation to date.

ACKNOWLEDGMENTS

In its program of exploration of mine~al deposits, the Bureau of Mines has as its primary 9bjective the_more effective utilization of our mineral re­ sources to the end that they make the greatest possible -contribution to na­ tional security and economy. . It is the policy of·. 'the Bureau to publish the facts developed. by each e;icploratory project as soon as .practicable after its conclusion. The Mining Branch, Lowell B, Moon, chief, conducts preliminary examinations., performs the actual exploratory work, and pr.epares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes S6lJ'.\l­ ples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. s. Dean, assistant director, ii The Bureau of Mines will welcome reprinting of this paper, provided the following footnote aclmowledgment, is made; . "Reprinted from :)3urea,.u of Mines Report of Investigations 3926. 11 gJ Mining engineer, Albany Division., Mining Branch, Bureau of Mines. 1079 R.I. 3926 Special aclmowledgment is clue to s. H. Lorain, chief, Albany Division, Mining Branch and to s. R. Zimmerley, chi~f, Salt Lake City, Utah, Metallur­ gical Division, for analyses of the ores. · · HISTORY

The presence of quicksilver in the Glass Buttes district has been lmown since about 1930. ··The area 'imDiediately north of Middle Butte has been super­ ficially prospected by numerous t _es t pi ts, trenches, shafts, and short adi ts, which revealed a number of opalized zones. Many of these opalizecl zones con­ tain weak to strong concentrations of cinnabar. The area has not been ex­ plored thoroughly; no mercury has been produced from any of its deposits.

A block·;r'48 f~ll-size'ciaims'has'been locatcd"to·cover' a•1arge part of the area~ sections ' 34 and·3; Tps. ·23 anci'24'S~, l\; ·23 E.; ·w ~r-1~• 'These· claims, heia.· by· iocat:i.on~. are o,mea.·by H~ S~ Miller,' lfuiibcrinan of Bend, Ore. W. s. Lazi9r: ~9~~!.V~ ·??~~~Av~nu~, .P?r~~~d~ ?:e•, currently controls the property 1:lP~~r. a ;i?~<:-+,~~':-~~ni;s_ a~~emc~t •. :r. W. McDaniel, 44 Lake Place, Bend, Ore., has done much of the underground and surface exploration ·on the property.·:, '.:: : '. ~-: . .. ' · · · · ' · ·. . : : : : . · · · · .. · · " · ' · " · · · · · I • •., • t • PHYSICAL FEATURES AND COMMUNICATIONS

The Glass Buttes district is an area of low relief in .the Deschutes River drainage system near the northeast corner of Lake County, Ore. (S~e fl.g. 1.) The arid climate is marked by extremes of winter. and summer'temperature. Water for camp use is not available in the immediate area. Well water, how­ ever, can be obtained in limited supply on property 5 miles to the south. The region is sparsely coyered with scrub brush, sage, and juniper. Tim­ ber for plant construction and mine support would necessarily be trucked to the property. No electric power is available; hence any contemplated mine plant would require a Diesel or Diesel-electric installation.

The nearest supply point is Burns (population 2,600), 49 miles to the east 9ver Stat~ Highway 54 (U. s. 20). Bend (population 9,000) is 83.2 to the west over State Highway 54. Access from the highway to the property is over 3.3 miles of unimproved desert road. Limited spot surfacing, togethe~ with an estililated 0.5 mile of g:r:ade improvenent·, would be required to insure · year-ai~ound access to the deposits at the·north end of the property. Rail transportation is availaple at both Bend and Burns. IABqR AND LIVING CONDITIONS

. .. With. t1J.~ . exception of a number of small stock , the surround.ing region is uninhabited. No mine labor is knmm 'to be· available. Unskilled labor probably could be recr1.1ite.d from Bend or Burns by meeting current locar wages. Labor of this type would be adeq_uate for a 1?mall~scale operation un­ der the supervision .of a..1 experience~ foreman.

1079 - 2 .. 17 18 19

J/6 "' "' '------JJ"' flow\ contoct '--- "- ?'---.. nding Breccia, some ? '--- '---.. k frocturt hing Hg s ..,___.;; >(,• S coat. ,, 75~ 6 -...... __ ----- ...... Weak fractu9 ? - __----- HgS (-) ,,,.__71

IWIPI.111 I Weak channel 315 §eppJ• llo, . Lbt, Bcttos HgS (-) Jldth cu.> 1.k 514 2.9 0.025 0.10 515 5.2 0.525 e.so 51.S s.7 0.076 1.50 517 0.9 o.:uo e.20 518 5.0 0.055 0.70 519 1.1 0.216 4.50 SCALE 25 ~ 75 100 ft.

FIG. 3, TUNNEL NO. I, GLASS BUTTES MERCURY DEPOSIT Living accomodations are provided b'y three small shacks ·and _a store · house at the north end of the property. With a small· expend.i.ture· for reha­ bilitation, these shacks would furnish :primitive hou.sing fqr 6 men. DESCRIPTION OF TEE DEPOSITS The Glass .Buttes district is overlain by flow rock and a mantle of ~ecent pyroclastics. The flows, alternatinG from basaltic to ·g1assy· 1ava, are frao­ tured by faulting that is believed to ·be normal.

The glassy rooks nave been. affected locally"by hydrothermal action evi­ dently concentrc.ted in and along zones of fracturing. This alteration has resulted in more or less complete opa:)..ization of s·o:rhe of the glassy rocks~ In a ·number of places, delicate flow banding is preserved in the opalite.

The opalized zones have been fractured and brecciated along narrow bands usually trending nortliwest and dipping steeply to the north~ · Some of the·se fractures and brec_cia bands have been filled and replaced with widely ranging concentrations of cinnabar. · ·

A fair degree· o:t presistency for some of _these mineralized fractures is suggested by exposures· in the No; l tunnel · (See fig. 3). · Strike and dip ex­ tensions of about 170 feet may be assumed in this working.

THE ORES

Cinnabar occurs in the Glass Buttes prospects as replacements, fracture fillings, and coatings on brecciated opalite. Many of the more loosely com­ pacted breccias are lightly filmed with cinnabar. Other breccias appear to have been predominantly mineralized by incomplete replacement and fracture fillins. A single breccia zone,~owcver, may contain all three types of mineralization. With the exception of tiny veinlets cutting the opalite, no massive cin­ nabar was found in any of the openings examined. Tho highest-grade material appears to be partly replaced opalito. Tho mercury content of tho coated breccia is insignificant.

A number of samples were cut from representative breccias in the No. l tunnel. (See fig. 3.) Assays and descriptions follow:

Srun.ple Percent Percent No. Width Hg. Cl2 Lb. He/ton Description 314 2.9 0.025 0.01* 0.50 Broccia; weakly coated, 315 3.2 .325 .01-* 6. 50 Breccia; cinnabar replacement. 316 3.7 .075 • 01* 1.50 Braccia and stained clay • 317 .9 .310 .01-* 6.20 Breccia; cinnaba! replacement. ~18 '). 0 . 035 • 01* • 70 Braccia; cinnabar coating only • ~ l.l .215 .01* 4.3() Breccia; replacement *Indicates 11 less than. 11

1079 - 3·· - R.I. 3926· These samples are- ·ind.icative of the gr-ad.e ·of ·the ·· several brecci-a. types. It appears that the mining grade obtainable· from ~everal of the veins may be raised to some -extent by careful hand sorting~

MINE WORICTNGS

Numerous test pits, four short prospect adits, and. three shallow shafts dot the area.· (See fig. 2.) Most of these widely·· scattered openings have exposed traces of mercury mineralization.

The most significant openings -examined. were the No. 1 tunnel and the North shaft 950 feet northwest of the No . ·l portal. The No . 1 ·tunnel (see· figs. 2 and ·3) has been driven west 380 £eet to intersect a mineralized frac­ ture exposed by an open cut 100 feet vertically above the adit level. The fracture has been further explored by a 48-foot winze sunk from the adit sill.

· The North shaft has been sunlc to a depth of 45 feet.; · A level has been · turned off at the bottom of the shaft and -advanced 10 feet -to the east. Both shaft and drift expose a mineralized breccia about 2 feet· wide.

The underground workings examined are in fair cond'ition, although some of the drift sets have rotted and re~uire timberihg. The ground ·stands well; it re~uires support bnly in the breccia zones·.

1079