MISCELLANEOUS FIELD STUDIES DEPARTMENT OF THE INTERIOR MAP MF-1353-C UNITED STATES GEOLOGICAL SURVEY 112'45' 21 EXPLANATION MINES AND PROSPECTS Most of the mines and prospects in or near the Stansbury Roadless Area ZONE WITH LOW TO MODERATE POTENTIAL FOR COPPER, LEAD, AND SILVER occur within a narrow north-trending zone, bordered on the west by the Late Devonian unconformity and on the east by the Broad Canyon thrust fault. All MINERALIZATION o f the workings in or near the roadless area are abandoned and caved or covered, and all are inactive. The Stansbury RoarlleF!S Area includes most of the Third Term and a small SAMPLE LOCALITIES part of the Free Coinage mining districts (fig . 1), The Third Tenn mining di.strict, originally called the Grantsville mining district, was organized U.S. Bureau of Mines June 15, 1875, for claims reporting lead, silver, and copp"'r (Butler and • others, 1920, p. 147, 149). Production is not recorded for any deposits within area D4757. Two claims in the district near the Stansbury Road less U.S. Geological Survey Area have had very limited production over a period of 80 years, with the most recent production in 1950. Mine location records for the period before 1885 were not available in the Tooele County courthouse, The Free Coinage mining district was organii:ed May 29, 1895, to include claim.s for clay and limestone (Butler and others , 1920, p. 146). Later claims CORF.ELATION OF MAP UN I TS in the district have been filed for silver, lead , zinc, and mercury. Five claims in the mining district north of the Stansbury Roadless Area have had a very limited production over a period of 25 years with t he most recent } Ho loc<c.ne and Pl eistorene } QUATERNARY production in 1942. Several canyons along the east flank of the range near the central part 35' Cnconfbrmity 36' of area D4757 have been extensively prospected. The Mining Fork of South Willow Canyon and Davenport, North Willow, and South Willow Canyons, together Oligocf>ne or l'.: ocene with intervening areas, contain most of the mines in or near the roadless area TERI lARY and include 33 adits, 26 pits , and 3 s hafts, The Western Star mine, Pa l o2ocene (?) } comprisi,1g two adits, is approximatel y 0.75 mi north of the roadless area. The Ahlstrom mine adit and another shaft are approximately 1 mi and 3 mi east, Uncon f arm Lt y respectively, of the southern spur of the roadless area, The U.S. Bureau of Mines has examined the mines and prospects in and near >Pu Lower Tr lassi e: and Upper Permian TRIASSIC AND P F.R MT AN the roadless area. The results of fire-assay and spectrographic analyses for Lower Permian and Up per 125 samples collected near the north, east, and south margins of the roadless MD PENN SY LVANIAN Pil' bm Penn s ylvan Lan l'ER'HAN area are summarized below. JP b p Mi dd le Pennsylvanian No. samples Grade P ENN SYLVAN lAN Metal containing 1P l o Lower Pennsylva nian metal Highest Average Lower Pennsylv3nian and I'f.NNSYLVAN TA.-'l I\.ND WMm Copper 73 0.08 % Up per Miss issippian 1 ' MISSISSIPPIAN Gold 3 0.04 oz/ton 0.018 oz/ton Mgb Lead 70 l3 % 0.52 % Upper Mississippint't Silver 69 7.4 oz/ton 0.6 oz/ton Zinc 18 % 0.93 % Mhd l11SS1SS1PPI AN 7. 5 All of the "highest value" samples are from localities outside of roadless Sg Lower Mississippian area U4757. None of the samples collected from within the roadless area appears to have any economic significance. Dps Upper DevonLrn DEVON IAN ASSESS~IENT OF MINERAL RESOURCE POTENTIAL Un c 0nf orm.i t y The following criteria were considered for this assessment: structure DSu DF.VO'\TAN AND STI.URI.AN and stratigraphy of potential host rocks, ore minerals or ore-related minerals suggested by rock or stream-sediment analyses, patterns of alteration Upper, Middle, and Lower Ou ORDO'.'ICIAN assoclated with ore deposits, ore minerals in outcrop, aeromag~etic da t a, and Ordovician history of economic ore deposits in similar nearhy geologic s"'ttings. Us i ng £a Upper Cam b rian these criteria, the metallic-mineral resource potential of an area can be classified as high, moderat~, or low. A high resource potential requires that Cc Upper and Middle> Cam brfan the geologic criteria be generally favorable and that there be a nearby deposlt that can reasonably be i nferred to extend into the study area. A. £Ce Middle Cambrian CAMBRIAN moderate potential :also requires g<>neral ly ff!.vorabl<> geologic criteri A anrl suggests that the extension of nearby deposits into the district be less £ 0 Midd le and Lower Cambriar, certai n. A low resource potential is predicted if most or all of the geologic criteria are unfavorable . €t Lower C:ambrian Mines aud prospects in and near area D4757 consist of small low-grade ' subeconomic deposits of copper-, lead-, and silver-bearing ,nluerals . These 'I'' ', I 1' depos i ts occur i.n a narrow north-trendj_ng zone that is mainly in the upper I ,I ,, plate of the Broad Canyon thrust fault near the Late Devonian unconformity . ) ' Because of this patter_n of occurrence, tracts within area D4757 that are l ..,q ""'---i~+-+-H-+-h4-++-++ between Magpie Canyon and Big Hollow Canyon and west of the Broad Canyon DESCRIPTION OF MAP UNITS thrust, together with a narrow :i:one east of the thrust, are identif ied as having a low to moderate potential for copper, lead, and silver 40'30' Qu SURFI CIAL DEPOSITS, UNDIVIDED (QUATERNARY) mineralization. Results of fire- assay and spectrograph ic analyses suggest that any ne~r-surface deposits present are small and low grade . Limestone and dolo:nite are the principal nonmetallic resources in area TV VOLCAN I C ROCKS (TERTIARY) D4757 . These commodities have been quarried for a number of years at several i . sites near Flux on State Highway 138. The Great Blue and Deseret Limestones / i, Tmp MONZONITE PORPHYRY (TERTIARY) are the best sources for l imestone and dolomi te, respectively, in area D4757, and underlie approximately 50 acres along the north side of Davenport Canyon Tc CONGLOMERATE (TERTIARY) and near the head of Magpie Canyon, An extensive. program of sampling and SEDIMENTARY ROCKS, UNDIVIDED (TRIASSIC A.l{D PERMIAN)-..:Thaynes Li!ll.estone, Woodside, Phosphoria, and testing is needed in order to evaluate this industrial mineral resource. 1'Pu Park City Formations, Dianmnd Creek Sandstone, and Kirkman Limestone There is no evidence of current or past quarrying operatious wlthin the OQUIRRH GROUP roadless area. The Utah Geological and Mineral Survey (1980) has designated lands in the PJPbm BINGHAM MINE(?) FORMATION (PER."'!IAN AND PENNSYLVANIAN) northwest corner of area A4757 as prospectively valuable for geothermal resources; however , no geothermal resources are known or included within area 1Pbp BUTTERFIELD PEAKS FORMATION (PENNSYLVANIAN) D4757 and the potential for such is low. Oil and gas leases have been issued for approxi1nately 73 acres in the !'le LOWERMOST PART OF OQUIRRH GROUP (PENNSYLVANIAN) southern spur of the area, near State Highway 199; applications have also been filed f or oil and gas leases on approximately 12,800 acres in the eastern and Him MANNING CANYON SHALE (PENNSYLVANIAN AND MISSISSIPPIAN) southern spur areas. It is assumed that explorati on eff orts have tested either the Tertiary basins that flank the Stansburys or Mesozoic strata that Mgb GREAT BLUE LIMESTONE (MISSISSIPPIAN) may underlie the region at great depth and which elsewhere are productive reservoir rocks. The potential for oil and gas deposits in the Stansbury Rosdless Area cannot be determined without an extensive geophysical Mhd HUMBUG FORMATION AND DESERET LIMESTONE, UN DIVIDED (MISSISSIPPIAN) exploration program. Mg GARDISON LIMESTONE (MISSISSIPPIAN) REFERENCES Dpa PINYON PEAK LIMESTONE AND STANSB URY FORMATION, U~DIVIDED {DEVONIAN) Bu tler, B. S., Loughlin, G. F,, Heikes, V. C., and others, 1920, The ore DOLOMITIC ROCKS, UNDIVlDED (DEVONIAN AND SILURIA.l{}-- Simonson(?), Sevy(?), and deposits of Utah: U.S. Geological Survey Prof essional Paper 111, 672 p. DSu Laketown Dolomites Sorensen, M. L,, 1982a, Geologi c map of the Stansbury Road less Areas, Tooele SEDIMENTARY ROCKS, UNDIVIDED (ORDOVICIAN)--Fish Haven Doluraite, Kanosh Sh.ale, County, Utah: U.S, Geological Survey Miscellaneous Field Studies Map Ou and Garden City Formation MF-1353-A, scale 1:62,500. ____1982b, Map showing geochenical analyses of panned stream sediments, €a AJAX DOL0!1ITE ( CAMBRIAl."\/) Stansbury Roadless Areas, Tooele County, Utah: U.S. Geological Survey Miscellaneous Fie ld Stud ies Map ~F-1353-B, scale 1:52,500. CARBONATE ROCKS, UNDIVIDED (CAMBRIAN)--Dunderberg Shalc,and Opcx Formation, Cole Canyon €c Utah Geological and ~ineral Survey, 1980, Geothermal resources of Utah 1980 : and Bluebird Dolomites, Bowman and Herkimer Limestones, and Dagmar Dolomite scale 1:500,000. £tc TEUTONIC LIMESTONE (CAMBRIAN) €c OPHIR GROUP OF RIGBY (1958) (CA~ffiRIAN) €C TINTIC QUARTZITE (CAMBRIAN) MAP SYMBOLS CONTACT --'-- - - 25' 25' FAULT--Dashed where approxima t ely located. Bar and ball on <lawn.thrown side 41°oo·,------'~'~"°';"4~5''----~------ - '---'~1~t'µ,o~·c_ ___ _ _____~ ....................... THRUST FAULT --Dotted where concealed. SHw teeth on upper plate ,, ... FOLDS--Showing axial trace. Dotted where concealed GREAT SALT LAKE Salt. Lake City Anticline / -+ / \ \ I -t- Sync line Area oi f,gure I \ I I \ STRIKE ANU DIP OF BEDS UTAH I I I I STANSBL!RY ' \ Inclined \ \ \ ISLANI;> ' I -+- Vertical I / I I Overturned \ / \ \ I I I \ BOUrs.'IJARY OF ROADLESS ARE,\S '-- \ -, \ \ T1S I I I STUDIES RELATED TO WILDERNESS I I // The Wilde rness Act (Public Law 88-577, September 3, 1964) and related I / Mining District \.~---/ acts require the U.S.