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Home , Allanite, Avalon Rare Metals, Black sand, Euxenite, Fergusonite, Fluocerite

RARE EARTH ELEMENT PROSPECTS AND OCCURRENCES IN UTAH

Ken Krahulec

Utah Geological Survey

a division of Utah Department of Natural Resources

Utah Trust Lands

The State of Utah School and Institutional

Trust Lands Administration

Although this product represents the work of professional scientists, the Utah Department of Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding its suitability for a particular use. The Utah Department of Natural Resources, Utah Geo- logical Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or consequential damages with respect to claims by users of this product. Cover: Spor Mountain Be mine, Juab County, looking north. The Be occurs in a half- graben with the main fault along the northwest (left) wall of the pit. The hanging wall rocks are dipping about 25° to the northwest, note the dip slope near the track hoe in the right-center of the photograph. Ore is hosted in the Miocene, light-gray, tuff member of the Spor Mountain Formation exposed in the corner of the pit (left-center). Geochemistry suggests that the Be ore is also enriched in REE.

2011 CONTENTS

EXECUTIVE SUMMARY ...... 1 INTRODUCTION ...... 2 Geochemistry ...... 2 Production and Markets ...... 4 REE MINERALOGY ...... 4 IMPORTANT REE DEPOSITS...... 7 Bayan Obo, ...... 7 Mountain Pass, California...... 8 Mount Weld, Western Australia ...... 9 Thor Lake, Northwest Territories, ...... 9 Other U.S. REE Deposits...... 10 UTAH REE PROSPECTS...... 11 Paleoproterozoic ...... 12 Upper Paleozoic Phosphorites ...... 16 Jurassic Intrusive Systems ...... 17 Gold Hill, Tooele County ...... 17 Peak, Tooele County...... 18 Cretaceous Fossil Placer Deposits ...... 19 Eocene Intrusive Systems ...... 21 Ibapah Batholith, Juab County...... 21 Lucin District, Box Elder County ...... 23 Oligocene Intrusive Systems...... 24 Washington District, Beaver County ...... 24 Pine Canyon, Piute County...... 25 Intrusive Complexes of the Colorado Plateau ...... 25 Miocene Intrusive Systems ...... 26 Springs, Iron County ...... 26 Monroe Canyon, Sevier County ...... 27 Spor Mountain, Juab County ...... 27 Sheeprock Granite, Tooele County...... 30 Blawn Mountain, Beaver County ...... 32 Newton District, Beaver County...... 33 Granite District, Beaver County ...... 34 Pliocene Intrusive Systems ...... 34 Honeycomb Hills, Juab County ...... 34 Smelter Knolls, Millard County...... 36 Unusual REE Occurrences...... 36 Cane Creek Potash Mine, Grand County...... 36 South Ouray Oil Shale, Uintah County...... 36 SUMMARY...... 37 ACKNOWLEDGEMENTS...... 39 REFERENCES ...... 39 APPENDIX. Periodic table of the elements with the REE highlighted ...... 47

FIGURES

Figure 1. Rare-earth oxides, clockwise from top center: , , , , , and ...... 3 Figure 2. Location map of important North American REE properties discussed in text ...... 8 Figure 3. REE localities of Utah, with locations listed in order of appearance in text...... 15 Figure 4. Closeups of Farmington Canyon Complex . A. Pegmatite boulder: very coarse-grained, cream-colored , smoky gray , very pale green plagio- clase (altered), and minor specks after pyrite. B. Pegmatite boulder: white , smoky gray quartz, and dark clots of -chlorite replacing red . 16 Figure 5. -chalcedony-bertrandite Be ore nodule from an open pit at Materion's (Brush Wellman) Spor Mountain operation, Juab County...... 29 Figure 6. Topographic map of beryllium open pit mines (red polygons) in the pediment south- west of Spor Mountain; SITLA rights are designated by blue outlines...... 30 Figure 7. Topographic map of the Eagle Rock Ridge area, southeast of Spor Mountain, Juab County ...... 31 Figure 8. Bell Hill at the Honeycomb Hills, Juab County, looking west ...... 35

TABLES

Table 1. REEs atomic numbers, and abundances (ppm) ...... 2 Table 2. Primary uses for REE ...... 5 Table 3. REE-bearing ...... 5 Table 4. REE deposit types...... 7 Table 5. Summary statistics for selected elements in NURE stream sediment samples, Utah.. 13 Table 6. Geochemistry of REE Prospects and Occurrences in Utah ...... 14 Table 7. Utah REE Prospects...... 38

EXECUTIVE SUMMARY minerals, and/or geochemical data. Unfortunately, the geochemical data The rare earth elements (REE) are a compiled for this report were not collected group of 16 geochemically similar lithophile for REE, analyzed for all of the REE, nor elements including the 15 and selected in hopes of collecting REE enriched . The REE are commonly divided material and consequently should be viewed into two groups - light REE (La, Ce, Pr, Nd, only as a semi-quantitative tabulation of areas Pm, Sm, and Eu) and heavy REE (Gd, Tb, that may have REE potential. Dy, Ho, Er, Tm, Yb, and Lu). Yttrium (Y), The most favorable sources for REE the lightest REE, is generally included in the production in Utah are byproducts of existing heavy REE group because it often occurs in operations (Simplot ), association with them in nature. In igneous Be mines (Materion Natural Resources), Fe rocks, the REE act as incompatible elements mines (CML ), or possibly potash and are concentrated by magmatic (Cane Creek). The most favorable differentiation into the last crystallizing area for REE on SITLA lands is in the Spor stages of igneous rocks, , Mountain mining district of Juab County. alkaline intrusive rocks, aplites, and Geochemical analysis of 46 ore samples from pegmatites. In sedimentary rocks the REE the Spor Mountain Be deposits (averaging most commonly occur in phosphorites and 0.63% Be) shows moderately anomalous placer deposits. REE assays. These samples are heavy REE- The world’s total primary REE market is enriched, have an estimated total REE value estimated to be a $2 to $3 billion industry, of very approximately $24 per short ton at too small a market for the major current prices, and could constitute a multinational mining companies. REE significant byproduct credit to the Be production is dominated by China (91%) and operation. SITLA controls the mineral rights recently, China began to increase export taxes (about 8250 acres) under private surface and limit the export of REE raw materials, ownership to a large block of ground in the recently suggesting that it might halt raw main Be-producing area southwest of Spor REE exports after 2015. This has prompted Mountain. strong increases in REE prices resulting in a In addition, one NURE soil sample from resurgence of REE exploration and southeast of Spor Mountain was very development in the west. The current major strongly anomalous in La (22,947 ppm) and producer (Bayan Obo, China) and the two Sm (132 ppm). This sample could be most advanced development projects considered “ore grade,” at an estimated $138 (Mountain Pass, USA, and Mount Weld, per ton total REE. SITLA has the surface Australia) are primarily light REE-enriched and mineral rights to partial section 2, T. 13 deposits, suggesting potential future markets S., R. 12 W., SLBM (607 acres) and the E½, for the more valuable, but rarer, heavy REE. E½, section 36, T. 12 S., R. 12 W., SLBM Utah has had no recorded REE (160 acres), immediately south and east, production and has no known carbonatites; respectively, of this site, which is on BLM however, REE occur in a wide variety of ground. geological environments in Utah ranging Braitschite, a REE-bearing mineral, is from Paleoproterozoic pegmatites to Pliocene reported from the Cane Creek potash mine, high-silica rhyolites. The potential sources of and a NURE stream sediment sample taken REE in Utah were evaluated based on a below their evaporation ponds is moderately favorable deposit types, recognized REE anomalous in several of the REE. There is a

1 large SITLA mineral rights block (about ppm) and copper (55 ppm), for example. 13,545 acres) covering the Cane Creek potash However when they were first recognized in operation in T. 26 and 27 S., R. 20 and 21 E. the late 1700s, they were believed to be rare and there may be some potential for a REE and were termed “earths” because they were byproduct to this mine. initially found as earthy looking oxides (Christie and others, 1998). INTRODUCTION Geochemistry The rare earth elements (REE) are not all that rare, with earth crustal abundances The REE are a group of 16 geochemically ranging from 0.3 to 64 parts per million similar lithophile elements in Group 3 of the (ppm) (table 1), compared to some of the Periodic Table (Appendix), which typically more well known elements like gold (0.002 occur together in minerals. The REE metals

Table 1. REEs atomic numbers, and abundances (ppm).1 Atomic Atomic Crustal Price3 Element Symbol Number Weight Valence Abundance2 Oxides REO/REE $/lb

Lanthanum La 57 139 3 30.0 La2O3 1.17 2.52

Cerium Ce 58 140 3,4 64.0 CeO2 1.23 1.88

LREE Praseodymium Pr 59 141 3,5 7.1 Pr6O11 1.21 11.68

Neodymium Nd 60 144 3 26.0 Nd2O3 1.17 12.13 Promethium4 Pm 61 145 3 0.0 No market

Samarium Sm 62 150 2,3 4.5 Sm2O3 1.16 2.04

Europium Eu 63 152 2,3 0.9 Eu2O3 1.16 217.69

Gadolinium Gd 64 157 3 3.8 Gd2O3 1.15 3.47

Terbium Tb 65 159 3,4 0.6 Tb4O7 1.18 158.73

Dysprosium Dy 66 163 3 3.5 Dy2O3 1.15 58.73 HREE Ho 67 165 3 0.8 Ho2O5 1.24 11.51

Erbium Er 68 167 3 2.3 Er2O3 1.14 11.56

Thulium Tm 69 169 3 0.3 Tm2O3 1.14 358.28

Ytterbium Yb 70 173 2,3 2.2 Yb2O3 1.14 70.43

Lutetium Lu 71 175 3 0.3 Lu2O3 1.14 107.94

Yttrium Y 39 89 3 22.0 Y2O3 1.27 4.65

Non-REE elements that may occur in REE deposits.

Scandium Sc 21 45 3 16.0 Sc2O3 1.53 400.00

Zirconium Zr 40 91 4 100.0 ZrO2 1.35 380.00

Niobium Nb 41 93 5,3 11.0 NbO2 1.34 18.00

Cesium Cs 55 133 1 3.0 Cs2O 1.06 No market

Tantalum Ta 73 181 5 1.0 Ta2O5 1.22 40.00

Thorium Th 90 232 4 3.5 ThO2 1.14 12.00

1. Modified from Castor and Hedrick, 2006. 2. Taylor and McClennan 1985. 3. Approximate 99% purity oxide prices based on January 2011 market. 4. Does not occur in nature. 2 are generally silvery in color, but tarnish crystallizing stages of felsic igneous rocks, rapidly to oxides (figure 1). Included in the alkaline intrusive rocks, aplites, and REE are yttrium and 15 lanthanides1. The pegmatites. The REE are often associated lanthanides are commonly divided into two with other incompatible elements, notably the groups - light rare earths (LREE) and heavy common (also Group 3 elements) rare earths (HREE). The LREE include Th and U in addition to Zr and Nb. REE also lanthanum (La), cerium (Ce), praseodymium naturally occur with phosphate, beryllium, (Pr), neodymium (Nd), (Pm), barium, fluorine, gallium, and samarium (Sm), and (Eu); minerals in various geologic environments. (Th), while not a REE, typically occurs with The REE generally have low mobility in the this group. The HREE include gadolinium surface/weathering environment, in part, due (Gd), (Tb), (Dy), to the refractory nature of their primary holmium (Ho), (Er), (Tm), minerals, e.g., , and also due to their (Yb), and (Lu). Yttrium strong tendency to form relatively immobile (Y), the lightest REE, is generally included oxides and placer deposits. The LREE are with this group because it often occurs in even less water soluble than the HREE. It is association with the HREE. The HREE are difficult to refine rare earth minerals to pure generally less abundant and more valuable metals because of (1) their reactivity and (2) than the LREE (table 1). Some publications their chemical similarity to each other refer to the LREE as the cerium group, (Christie and others, 1998; Castor and cerium being their most abundant member, Hedrick, 2006). and the HREE as the yttrium group. Cerium One feature of note regarding elemental is the most abundant REE, accounting for abundance: there is an odd-even relationship approximately 30% of the total REE in earth in the Periodic Table with even numbered crustal abundance. elements usually being more abundant than Geologically, the REE are chemically their odd-numbered neighbors due to the incompatible with the common rock forming greater stability of their nuclei. This feature, minerals and so are concentrated by the Oddo-Harkins rule, is strongly evident magmatic differentiation into the last within the series (table 1).

Figure 1. Rare-earth oxides, clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium. Photograph by Peggy Greb, U.S. Department of Agriculture.

1Some publications only refer to the lanthanides as REE, other publications include yttrium, another Group 3 element of the Periodic Table, and still others add , another Group 3 element. In this paper I include yttrium with the lanthanides as REE, but not scandium, which is geochemically dissimilar in that it is not concentrated in felsic igneous phases, resulting in Sc not being associated with Y and the lanthanides in these phases.

3 Production and Markets The end uses of REE are, in decreasing order of importance: metallurgical The world’s total primary REE market is applications and alloys 29%; electronics estimated at about a $2-3 billion. REE, rare 18%; chemical catalysts 14%; rare-earth earth oxides (REO), and their compounds are phosphors for computer monitors, lighting, principally imported into the U.S. from China radar, televisions, and x-ray-intensifying film (91%) with minor imports from , 12%; automotive catalytic converters 9%; , Russia, Ukraine, and a few other glass polishing and ceramics 6%; permanent countries (Hedrick, 2010). There is currently magnets 5%; petroleum refining catalysts no government stockpile of REE. In 2005, 4%; and other 3% (table 2). is an China began to increase export taxes and alloy of REE and Fe used in the production of severely limit the export of REE raw flint for lighters. Recent trends show materials, exports of REE were cut by 40% in increasing use of REE in automotive catalytic 2010 and 35% more for 2011, and there are converters, permanent magnets, and suggestions of a total ban on raw REE rechargeable batteries for electric and hybrid exports in 2015. These developments have vehicles (Hedrick, 2010). prompted strongly increasing REE prices in The marketing of REE can be difficult and a resurgence of REE exploration and because the mine product is likely to be a development in the west. REE mineral concentrate and each deposit Production of REE in western countries has a different REE suite. The product is has been declining, in part due to the generally sold under a contract between common association of Th and U with the buyer and seller. This method of sales is REE deposits. If the Th and U are not similar to that typically used in industrial recovered, the tailings may be radioactive and minerals, but is generally unlike the more subject to greater environmental monitoring broadly traded markets for base and precious and remediation. This has been a large metals, for example. Marketing is concern for the Mountain Pass REE (±Th) complicated by fixed REE ratios in each deposit in California, once the world’s largest deposit, but variable market demand for REE producer, where production was halted individual REE (Castor, 2008). in 2002. REE are also occasionally produced The largest REE producer in the world, as by-products from the milling of some Fe, Bayan Obo, China, and the two other large Th, U, Nb, W, fluorite, and phosphate . deposits headed toward production, Mountain REE ores containing bastnasite as the Pass, CA, and Mount Weld, Australia, are all primary ore mineral are typically processed primarily LREE-enriched. This suggests that by hot froth flotation, and may be followed the rarer and more valuable HREE may by leaching. Monazite ores are usually remain in short supply for the near term. processed by gravity concentration followed Currently there is tight supply for Nd, Tb, by electrostatic and/or magnetic separation. Dy, and, to a lesser extent, for Sm and Pr. Some REE concentrates can be processed in Future production shortages are projected for an autoclave and repetitively leached to yield Dy, Tb, and Y. more refined products. Selective solvent extraction can be used to make nearly pure REE MINERALOGY REE metals (Christie and others, 1998). Capital costs for a REE plant are estimated at The most important REE ore minerals are roughly $40,000 per ton of annual REO bastnasite, hydroxylbastnasite, thorbastnasite, production capacity.

4 Table 2. Primary uses for REE Atomic Element Selected Uses Number Symbol Nickel- (lanthanum) hydride car batteries, petroleum cracking catalysts, high glass, sparking flint, Lanthanum 57 La fuel cells, battery-electrodes, phosphors are used in X-ray films Optical glass and glass polishing compounds, catalytic con- Cerium verters, diesel fuel additive, silicon microprocessors, UV radia- 58 Ce tion shield, compact fluorescent lighting LREE Permanent rare-earth magnets, photographic filters and Praseodym- welder’s glasses, vibrant yellow pigment for ceramic tiles and 59 Pr ium glasses, permanent REE magnets High strength Nd-Fe-B magnets, lasers, sky-blue pigments for Neodymium ceramic tile and glass, ceramic capacitors, petroleum-cracking 60 Nd catalysts Samarium Rare-earth magnets, lasers, neutron capture, pigment for glass 62 Sm

Europium Red phosphors, lasers, mercury-vapor lamps, fluorescent 63 Eu Rare-earth magnets, high refractive index glass or , Gadolinium lasers, x-ray tubes, computer memories, radiation leak detec- 64 Gd tors Magneto-optic recording tape, green phosphors, fuel cells, fluo- Terbium 65 Tb rescent lamps, sonar systems

HREE Dysprosium Ceramic capacitors, REE magnets, lasers, control rods for nu- 66 Dy Holmium Control rods for nuclear reactors, catalysts, refractories 67 Ho Lasers, vanadium steel, optical fiber cables, pink pigment of Erbium 68 Er glass and glazes in ceramics Thulium Portable X-ray machines 69 Tm Stress gauges, infrared lasers, chemical reducing agent, high- Ytterbium 70 Yb temperature superconductors as Yb-Ba-Cu oxide (YBCO)) Lutetium Ce-doped Lu oxyorthosilicate (LSO) is used in detectors in 71 Lu

Phosphors for televisions, computer monitors, fluorescent Yttrium lights, and x-ray-intensifying screens; yttria-stabilized zirconian 39 Y in abrasives, bearings, and high-temperature refractories Table 3. REE-bearing minerals.

REO Mineral Formula wt % Primary sources

Aeschynite (REE,Ca,Fe,Th)(Ti,Nb)2(O,OH)6 36 alkaline igneous rocks

Allanite (Ce,Ca,Y,La)2(Al,Fe)3(SiO4)3OH 30 carbonatites, pegmatites, veins, placers

Anatase TiO2 3 placers

Ancylite Sr3(Ce,La,Dy)4(CO3)7(OH)4•3H2O 46 carbonatites, pegmatites alkaline igneous rocks, phosphorites, (Ca,Na,Sr) ((La,Ce,P,S)O ) (OH,Cl) <19 5 4 3 pegmatites

Bastnasite (Ce,La)(CO3)F 76 carbonatites

Braitschite (Ca,Na2)7(Ce,La)2B22O43•7(H2O) 20 evaporites

Brannerite (U,Ca,Y,Ce)(Ti,Fe)2O6 6 pegmatites, veins, placers

Britholite (REE,Ca)5(SiO4,PO4)3(OH,F) 62 alkaline igneous rocks, pegmatites

5 Table 3. continued. REO Mineral Formula wt % Primary sources

Brockite (Ca,Th,Ce) PO4• H2O 7 carbonatites, veins

Burbankite (Na,Ca)3(Sr,Ba,Ce)3(CO3)5 7 carbonatites, phosphorites, evaporites

Calcioburbankite Na3(Ca,REE,Sr)3(CO3)5 25 carbonatites, phosphorites, evaporites

Calkinsite (Ce,La)2(CO3)3•4H2O 61 carbonatites, phosphorites, evaporites

Cerianite (Ce,Th)O2 63 alkaline igneous rocks

Cheralite (REE,Ca,Th)(P,Si)O4 25 pegmatites

Churchite YPO4•2H2O 44 laterites alkaline igneous rocks, pegmatites, Cyrtolite Zr Hf REE SiO 4 0.9 0.05 0.05 4 placers

Eudialyte Na15Ca6(Fe,Mn)3Zr3(Si,Nb)Si25O73(OH,Cl,H2O)5 10 alkaline igneous rocks

Euxenite (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6 <40 pegmatites

Ewaldite Ba(Ca,Y,Na,K)(CO3)2 10 phosphorites, evaporites

Fergusonite (Y,Er,Ce,Nd,La,Fe)(Nb,Ta,Ti)O4 47 alkaline igneous rocks, pegmatites

Florencite REE Al3(PO4)2(OH)6 32 carbonatites

Fluocerite (La,Ce)F3 83 veins

Gadolinite (Y,Ce,La,Nd)2FeBe2Si2O10 52 pegmatites

Hibonite (Ca,Ce)(Al,Ti,Mg)12O19 5 metamorphic rocks

Huanghoite BaREE(CO3)2F 38 carbonatites, veins

Hydroxylbastnasite (Ce,La,Nd,Th)(CO3)(OH) 75 carbonatites

Iimoriite (Y,REE)2(SiO4)(CO3) 68 pegmatites

Kainosite Ca2(Y,REE)2Si4O12CO3•H2O 38 alkaline igneous rocks, pegmatites

Loparite (REE,Na,Ca)(Ti,Nb)O3 36 phosphorites

Mckelveyite Ba3Na(Ca,Sr,U)Y(CO3)6•3H2O 11 phosphorites, evaporites carbonatites, alkaline rocks, pegmatites, Monazite (Ce,La,Nd,Th,Sm)PO <71 4 placers

Mosandrite (Ca,Na,REE)12(Ti,Zr)2Si7O31H6F4 <65 alkaline igneous rocks

Parisite CaREE2(CO3)3F2 64 veins

Rhabdophane (Ce,La,Nd)PO4•H2O 65 carbonatites

Samarskite (Y,Ce,U,Ca,Th,Fe)(Nb,Ta,Ti)2(O,OH)6 12 pegmatites carbonatites, pegmatites, alkaline Synchisite Ca(Ce,La,Nd,Y)(CO ) F 51 3 2 igneous rocks

Thalenite Y3Si3O10(OH) 63 veins

Thorbastnasite Th(Ca,Ce)(CO3)2F2•3(H2O) 8 carbonatites pegmatites, alkaline igneous rocks, ThSiO - 4 veins, placers pegmatites, alkaline igneous rocks, (sphene) (Ca,REE)(Ti,Al,Fe)SiO 4 5 placers

Tveitite (Ca,REE)F2 27 pegmatites, veins alkaline igneous rocks, pegmatites, YPO 61 4 placers, veins

Yttrocerite (Y,REE)F3 43 high-silica rhyolites

Yttrotantalite (Y,U,Fe)(Ta,Nb)O4 <24 pegmatites

Zirconolite (Ca,Ce)Zr(Ti,Nb,Fe)2O7 9 carbonatites

Modified from King and Hausel (1991) and Castor and Hedrick (2006). 6 monazite, and xenotime (table 3). Other (, Idaho), placer deposits (Oak mineral phases that may contain economic Grove, Tennessee), paleoplacer deposits concentrations of REE include allanite, (Elliot Lake, Canada), and fluorite deposits ancylite, some , braitschite, cyrtolite, (Gallinas Mountains, New Mexico) have all , fergusonite, fluocerite, hibonite, been exploited for REE and phosphorite iimoriite, samarskite, synchysite, titanite, and deposits (Phosphoria Formation, Idaho) . The similar ionic radii and contain a known, albeit low-grade, resource valence (typically trivalent) in the REE result (Castor, 2008). in common substitutions between them in mineral phases, particularly within the LREE Bayan Obo, China and HREE groups (Castor and Hedrick, 2006). The world’s largest REE and second Grades for REE deposits are normally largest Nb producer is the Bayan Obo Fe- reported as percentages of combined total REE-Nb deposit in , China. REO (TREO). Cutoff grades for REE The deposit was first discovered in 1927, production obviously vary, but tend to be accounts for nearly half of the world’s current around 1% TREO. Bastnasite (99%) and REE production, and contains an estimated monazite (97%) are predominantly ores of 70% of the world’s known REE resources. the LREE and xenotime (85%), allanite (5- The total reserves for Bayan Obo are reported 20%), and iimoriite are dominantly HREE as at least 1.65 billion short tons of 35% Fe, ores (Jackson and Christiansen, 1993). 6% REO, and 0.13% Nb. The ore is primarily enriched in LREE and the deposit IMPORTANT REE DEPOSITS has an extremely high LREE/HREE ratio (Chao and others, 1997; Smith and REE occur in a number of geological Henderson, 2000). settings (table 4). The most economically The geology of the Bayan Obo deposit is important REE deposits are related to Fe very complex. The deposits are epigenetic, oxide-REE ±Cu ±Au deposits (Bayan Obo, metasomatic, hydrothermal, and stratiform, China), carbonatites (Mountain Pass, hosted near the base of a section of Middle California), and alkaline igneous rocks (Thor Proterozoic dolomitic marbles. Lake, Canada). Ferrocarbonatites Mineralization is apparently related to characteristically contain more REE than Ca- dikes and sills emplaced during or Mg-rich carbonatites. Vein REE deposits the Caledonian orogeny with dates ranging from about 439 to 396 Ma. The primary ore Table 4. REE deposit types. Deposit Type Utah1 Carbonatite-related deposits No Iron-oxide–copper–gold deposits (Olympic Dam-type) Yes? Peralkaline and granite related deposits Yes Pegmatites Yes Hydrothermal vein deposits Yes Phosphorites Yes Beach placers Yes Residual laterites No Residual ion-adsorption clay deposits No

1Are these REE deposit types known in Utah? Modified from Christie and others (1998) and Castor and Hedrick (2006).

7 minerals are , hematite, monazite, bastnasite, and columbite associated with a Mountain Pass, California gangue of dolomite, alkali , fluorite, barite, , apatite, , and North America’s largest REE deposit is microcline. The ores range from massive, to Mountain Pass, California (figure 2). banded, to disseminated replacements with Mountain Pass began production in 1954 and associated fenitization (sodic metasomatism) was the world’s largest producer of REE (Chao and others, 1997; Smith and from the mid-1960s to the mid-1990s, when Henderson, 2000). The Bayan Obo deposit is production declined until mining was halted often compared to either Fe-oxide-Cu-Au in 2002 due to mounting environmental (Olympic Dam) or carbonatite-related REE restrictions in California. The shipment of deposits (Wu, 2008). Annual production is stockpiled concentrates from the property estimated at 61,000 short tons TREO, which resumed in 2004, mining was restarted in accounts for roughly 47% of the world’s December 2010, and production is scheduled production. The Paleoproterozoic Kiruna Fe to recommence in mid-2012. The Mountain ore district of northern also hosts Pass deposit still has the third largest known massive magnetite-apatite ore bodies with REE resource in the world (Castor and 0.7% TREO. Nason, 2004).

Figure 2. Location map of important North American REE properties discussed in text.

8 Mountain Pass is part of an 80-mile-long, magnetite and vermiculite, varying from 20 north-northwest-trending belt of anorogenic, to 100 ft thick, at depths of 150 to 300 ft ultrapotassic intrusions in southeastern below the surface. - and tantalum- California. The Mountain Pass REE deposit bearing and , and is associated with a 1400 Ma carbonatite and niobium-bearing are also concentrated comagmatic ultrapotassic alkaline intrusions in the apatite-magnetite residual zone. The which cut granulite facies and schist. most important REE resource is in the The carbonatite is surrounded by over 650 regolith above the central part of the feet (ft) of K-feldspar-rich fenitic alteration. carbonatite, while the higher grade Nb and Ta Current reserves are estimated at zones occur over the outer margins of the approximately 22 million short tons pipe. The REE deposit contains about 17 averaging about 8.9% REO. Mountain Pass million short tons averaging about 11.2% is presently producing about 3000 short tons TREO, including yttrium (Duncan and TREO per year from historic stockpiles as Willett, 1990; Jackson and Christiansen, they gear up for renewed production of 1993). Mount Weld is expected to come on 22,000 short tons per year in 2012, ramping line in late 2011, initially producing at 12,000 up to 40,000 short tons per year in 2013. The short tons per year TREO and ramping up to current annual production of TREO accounts 24,000 short tons per year. for roughly 2.5% of the world production and moves the U.S. into second place behind Thor Lake, Northwest Territories, Canada China. The carbonatite ore is composed of roughly 65% calcite-dolomite, 23% barite, The Thor Lake REE--niobium- and 12% bastnasite with locally important tantalum deposit is located on the north shore amounts of strontianite and talc. Like Bayan of and about 60 mi Obo, Mountain Pass has extreme LREE southeast of (figure 2). The enrichment and high LREE/HREE ratios; deposit was discovered in the early 1970s and however, unlike Bayan Obo, Mountain Pass is the third largest REE resource in North is low in Fe (Castor and Nason, 2004). America, hosting approximately 13.2 million short tons averaging 0.38% HREO, 1.32% Mount Weld, Western Australia LREO, 3.16% ZrO2, 0.41% Nb2O5, and 2 0.041% Ta2O5 . Thor Lake is part of a Mount Weld is a Paleoproterozoic (2064 Paleoproterozoic (2185 Ma) alkaline Ma) carbonatite complex intruded into an intrusive complex with phases ranging from Archean in the Yilgarn early and gabbro through Craton in Western Australia. Mount Weld is leucoferrodiorite, quartz syenite, and granite, a carbonatite plug approximately 1.5 miles to peralkaline3 granite and a late syenite. The (mi) in diameter. The carbonatite is deposit is genetically-related to the dominantly coarse grained dolomite and peralkaline Thor Lake Syenite and shows ankerite, with locally important biotite and features that reflect both magmatic apatite. The carbonatite contains about 3.5% segregation and hydrothermal-metasomatic apatite. overprinting. Metasomatism results in an A well developed lateritic regolith over alteration assemblage of biotite, magnetite, the carbonatite varies from about 60 to 300 ft specularite, albite, and/or chlorite associated in thickness. Apatite occurs in a residual with the REE resource. LREE mineralization layer near the base of the regolith with is principally in allanite, monazite, bastnasite,

2Recent work (September 2010) by Avalon Rare Metals has increased these reserves by approximately 55%. 3Peralkaline igneous rocks have an excess of sodium and potassium over aluminum above that required to form feldspar. The presence of aegerine (sodium ), (sodium amphibole), and/or is in- dicative of peralkaline conditions. 9 and synchysite. HREE and tantalum are ancylite and bastnasite. A historic resource primarily found in fergusonite and of about 17.5 million short tons averaging (Cox and others, 2010). 3.46% REO is indicated. The Bear Lodge intrusive complex also hosts some Cu and Au Other U.S. REE Deposits sulfide mineralization and is locally enriched in Th, U, F, Ba, Sr, and Nb (Castor, 2008). The Bokan Mountain U-REE-Th-Nb The Cambrian (570 Ma) Iron Hill deposit on Prince of Wales Island in intrusive complex is located near Gunnison in southeast Alaska (figure 2) has historically central Colorado (figure 2). The complex been exploited for its U mineralization (1.3 consists of, from oldest unit to youngest, million pounds U3O8), but has more recently pyroxenite, uncompahgrite, , come under consideration for its REE pyroxenite- syenite, nepheline potential, estimated at about 4.7 million short syenite, and a carbonatite stock. This tons of 0.39% REE (Warner and Barker, carbonate stock (about 1 sq mi) is the largest 1989). The deposits are related to the Jurassic known exposed mass of carbonatite in the Bokan Mountain peralkaline granite complex . The carbonatite is composed which covers about 3 sq mi. The granite is cut primarily of ankeritic dolomite and abundant, by numerous radial pegmatite, , dacite, but lesser amounts of calcite, , and aplite dikes that are genetically related to barite, and accessory siderite, magnetite, the complex and commonly associated with the ilmenite, phlogopite, biotite, sodic , U, Th, and REE deposits. Mineralization is and trace amounts of pyrite. The REE occur marked by albitization, chloritization, and primarily in bastnasite, synchysite, and argillization with minor calcite, fluorite, quartz, rhabdophane, and lesser amounts occur in sulfide minerals, and tourmaline in the ore fluorapatite, pyrochlore, and monazite. As zones (Warner and Barker, 1989). REE with other carbonatite-related REE deposits, mineralization is associated with elevated Iron Hill is enriched in LREE and contains a levels of U and especially high Th. The large, but low grade resource of 722.7 million central mineralized zones appear to be HREE short tons of 0.397% REO, 0.0043% ThO2, dominant and LREE occur more peripherally. and 0.057% Nb2O5. In addition, the The Bear Lodge REE deposit is located in pyroxenite stock also hosts a Ti resource of the southern Bear Lodge Mountains of 46 million short tons grading 13.2% TiO2 (Van northeastern , near the famous Gosen, 2009). Devils Tower neck (figure 2). The The Lemhi Pass Fe-Th-REE-Cu district REE deposit is associated with a covers a 50-sq-mi area of the Beaverhead northwesterly trending belt of Eocene (50.5 Mountains along the Idaho- border to 38.3 Ma) alkaline intrusives. The Bear (figure 2). The more than 200 Th-rich quartz Lodge deposit is hosted near the center of a veins in the Lemhi Pass district are thought to large alkaline intrusive complex composed contain the largest concentration of Th primarily of phonolite and trachyte porphyry resources in the United States. Most of these and breccia. The REE are concentrated in a veins are quartz-hematite-thorite [Th(SiO4)], swarm of poorly exposed, closely spaced, however, REE- and Th-bearing allanite and steeply dipping, carbonatite dikes. The monazite veins are locally abundant and carbonatite bodies range in size from veinlets overall the ratio of Th:TREE is roughly 1:1. to dikes approaching 50 ft in width. The The veins cut Proterozoic Belt Series rocks deposit is hosted in fenitized rock enriched in and appear to be related to a Cambrian (529 LREE and the primary REE minerals are Ma) syenite (80% feldspar) and an underlying carbonatite is suspected (Van

10 Gosen and others, 2009). The reserves of the bearing phase in the pegmatites (Adams, Last Chance vein alone are estimated at 1965). The REE are more abundant in roughly 1 million short tons of ore containing quartz-poor pegmatites associated with 0.39% ThO and 0.33% TREO. alkaline complexes. The Mesoproterozoic Fe ore deposits of The Pajarito Y-Zr deposit, also in New Iron Mountain district, southeastern Missouri, Mexico, is associated with an 1100 to 1200 are associated with unexploited REE Ma gabbro, syenite, quartz syenite, and alkali deposits. The massive magnetite-hematite granite complex (figure 2). The syenite, ore deposits are related to a 1480 Ma quartz syenite, and alkali granite contain granitic-syenitic intrusive complex. The disseminated . Eudialyte, a coeval REE deposits are hosted in small, late, zirconium silicate that contains Y, is the ore high-grade breccia pipes in the footwall of mineral. The Pajarito deposit has a the Pea Ridge Fe ore deposit (figure 2). The recoverable resource of 2.7 million short tons pipes contain monazite and xenotime, have grading 0.18% Y2O3 and 1.2% ZrO2 (Sherer, grades of up to 12% REE, and are enriched in 1990; McLemore, 1990). HREE (Castor, 2008). Marine phosphorite deposits can be Due to the resistant nature and high enriched in REE, and minor amounts of REE density of many of the REE minerals, they minerals are also recognized in phosphatic are often found in placer deposits. Placers shale deposits. The Permian Phosphoria are usually mined for a primary product other Formation is known to host low-grade than REE, such as ilmenite, rutile, tin, or (<0.1% REO) REE deposits in Idaho and gold; REO minerals, if recovered, are Montana (figure 2); however, no phosphate commonly byproducts. Monazite and operation currently recovers REO minerals xenotime are the primary REE minerals (Castor, 2008). typically present. Most of the U.S. examples REE can also be concentrated by intense of placer REE deposits are in the southeastern lateritic weathering of REE-rich primary states (figure 2). Paleoplacer deposits are sources, such as alkaline complexes; also known from rocks as old as Early however, these deposits are primarily located Proterozoic. Placer deposits are generally in subtropical climates and no important quite low grade, typically less than 0.1% deposits are currently recognized in the U.S. REO (Castor, 2008). (Christie and others, 1998). REE-bearing fluorite deposits have been very minor producers in the Gallinas district UTAH REE PROSPECTS in central New Mexico (figure 2). Bastnasite occurs in fluorite ±barite ±calcite ±Cu- Utah has had no recorded REE bearing veins and breccia fillings related to a production and has no known carbonatites; peraluminous4, alkalic trachyte intrusive in however, there are several reported REE the area. District zoning is from Fe skarns, to prospects and a number of known or Cu-F-REE veins, F-REE veins, and finally suspected occurrences. The suspected REE distal magmatic-hydrothermal breccias. The occurrences are typically defined by (1) Red Cloud mine in the Gallinas district favorable deposit type (table 4), (2) produced grades of up to 3.2% REO. Minor recognized REE minerals (table 3), and/or (3) REE are also reported from several granitic geochemical data. Favorable deposit types pegmatite deposits, possibly associated with are those known to host REE, mainly those the Rio Grande rift, in north-central New discussed above. The recognized Utah REE Mexico. Monazite is the primary REE-

4Peraluminous igneous rocks have aluminum in excess of sodium, potassium, and ; this is typically indi- cated by the presence of cordierite, andalusite, garnet, muscovite, and/or biotite.

11 minerals are primarily known from Bullock collected primarily for REE, nor analyzed for (1981). all of the REE. Virtually none of the samples The primary source of REE geochemical were collected in hopes of collecting REE data in Utah is the National ore. These data should be viewed as a Resource Evaluation (NURE) stream subjective, semi-quantitative tabulation of sediment sample database and the National areas that may have REE potential. Geochemical Database (NGDB). There are The Utah REE prospects and occurrences approximately 9859 NURE stream sediment are briefly described below and are arranged samples in Utah and most have been by age and deposit type. analyzed for some of the REE. The NURE program’s hydrogeochemical and stream Paleoproterozoic Pegmatites sediment sampling of the U.S. ran from about 1976 to 1984. Samples were primarily The Paleoproterozoic Farmington Canyon collected by contractors on the basis of 1° x Complex (about 1800 Ma) consists of a thick 2° quadrangles and analyzed by different sequence of and schists primarily methodologies and for a slightly different exposed on the west flank of the Wasatch suite of elements at one of four DOE national Mountains and Antelope Island in north- laboratories: Lawrence Livermore central Utah (Hintze and Kowallis, 2009). Laboratory, Los Alamos Scientific The Farmington Canyon Complex is of Laboratory, Oak Ridge Gaseous Diffusion interest for REE in two respects, the presence Plant, and Savannah River Laboratory. Only of one of the strongest NURE stream 307 quadrangles, out of a total of the sediment REE anomalies in the state and proposed 625 U.S. quadrangles were occurrence of numerous quartz-microcline- completely sampled and another 86 pegmatite dikes and massive quadrangles were partially sampled. The quartz veins. Some of the quartzofeldspathic summary statistics for a select suite of gneisses in the Farmington Canyon Complex elements from the Utah NURE stream are known to have a high background in REE sediment samples are shown in table 5. In (table 6) (Andreasen, 2007). addition, the NURE program also analyzed The NURE stream sediment REE some soil and rock samples collected in anomalies are mainly confined to the conjunction with the main stream sampling northern portion of the exposed Farmington program. Canyon Complex, southeast of Willard in The NGDB is a compilation of largely southeastern Box Elder County (figure 3, site previously published U.S. Geological Survey 11). These stream sediment anomalies range (USGS) rock geochemical data. The from, 301 to 418 ppm Ce in four samples, 287 to 513 ppm La in six samples, and 117 to database is a very poorly formatted 200 ppm Y in six samples (table 6). These mishmash of miscellaneous USGS streams drain the southern portion of the geochemical data, but does provide nearly Sierra Madre mining district. The Sierra 15,000 data points in Utah. The majority of Madre district is known to have produced these data have not been analyzed for many only very minor quantities of Cu-Ag ore. REE, however, and many are only very Bryant (1988) reports that both approximately located. concordant and discordant pegmatite dikes It is important to note that the REE and sills are common in the Farmington geochemical data used in this report is wholly Canyon Complex. The light pink-gray to inadequate. Most of the data were not white pegmatites are primarily composed of

12 Table 5. Summary statistics for selected elements in NURE stream sediment samples, Utah (n=9857).

AL % BA ppm BE ppm CA % CE ppm CS ppm DY ppm EU ppm Earth Crust 8.13 425 2.8 3.63 64 3.0 3.5 0.9 Number of Analyses 9,239 7,695 7,691 7,717 9,247 2,848 5,759 4,997 Median 4.12 441 1.5 2.41 46 2.2 3.0 0.9 Average 4.13 473 1.7 3.16 51 2.4 3.0 1.0 Maximum 11.25 14,690 125.0 27.49 2,886 17.1 74.3 9.9 Standard Deviation 1.65 397 2.3 2.87 49 1.5 2.3 0.8 Threshold 7.43 1,268 6.4 8.89 149 5.3 7.6 2.5

MO FE % HF ppm K % LA ppm LI ppm LU ppm MG % ppm Earth Crust 5.00 3.0 2.59 30 20 0.3 2.09 1.50 Number of Analyses 9,281 8,278 7,695 9,257 7,692 5,259 7,694 4,981 Median 1.70 7.0 1.50 25 23 0.3 0.78 1.50 Average 2.11 8.9 1.52 35 29 0.3 0.96 1.99 Maximum 36.58 223.6 4.14 1,958 245 3.8 8.72 331.00 Standard Deviation 1.87 9.8 0.49 41 25 0.2 0.75 6.26 Threshold 5.85 28.5 2.49 118 80 0.7 2.46 14.52

NA % NB ppm P ppm SC ppm SE ppm SM ppm SN ppm SR ppm Earth Crust 2.83 20 1,200 16.0 0.1 4.5 2.0 375 Number of Analyses 9,229 7,716 4,862 9,501 3,849 6,474 5,181 7,621 Median 0.61 10 600 4.9 0.1 3.0 2.0 111 Average 0.78 11 640 5.3 0.6 3.4 3.2 167 Maximum 9.74 728 9,600 33.0 40.0 30.0 85.0 3,192 Standard Deviation 0.63 15 453 3.2 1.1 2.0 3.7 163 Threshold 2.03 41 1,546 11.6 2.9 7.4 10.6 494

TA ppm TB ppm TH ppm TI ppm W ppm Y ppm YB ppm ZR ppm Earth Crust 2.0 0.6 10.0 5,700 1.5 22 2.2 165 Number of Analyses 2,002 1,948 9,002 9,097 5,201 4,874 5,387 2,622 Median 0.5 0.5 8.0 2,401 1.5 10 2.2 61 Average 0.5 0.5 9.9 2,840 1.5 12 2.2 81 Maximum 2.0 3.0 483.0 28,000 37.0 262 126.0 1,105 Standard Deviation 0.1 0.2 10.7 2,059 1.9 14 2.8 88 Threshold 0.8 0.9 31.3 6,959 5.2 40 7.8 258

REE are highlighted in yellow.

13 1

2.70 138 0.06 3 0.31 21 0.01 1 0.20 16 0.10 38 TREO Value TREO

11.7 0.02 6 30.0 0.36 45 79.9 37 0.07 37 3 20 70 7.0 0.33 37 45 4.3 0.07 9 45 18.3 0.07 6

600 19.0 0.21 0.06 34 430 5 358 21.7 0.16 24 700 20.0 0.20 500 20.0 0.12 200 7.0 0.07 19 13 8 700 20.0 0.30 31 120 0.13 120 7 172 0.0 0.13 126 15.0 0.08 6 15 160 0.20 160 9 140 0.11 140 5 327 1500 0.76 6000 60 1500 1000 1500 50.0 0.43 56

2.3 125 14.2 0.12 2.3 125 18

4.2 7.9 10.1

4.0 7.4 0.9 40 7.8 0.04 5 2.7

20.9 1.2 0.5 29 3.2 0.16 15 12.0 125.0 132.0 100.0

70 70

97 30 20.0 97 30 44 14.3 3.7 156 30.4 0.06 10 30.4 156 3.7 14.3 44 92 25 30.6 92 25

700 150 100.0 700 150 Some of the most highly Some of the mostelevated highly REE values are in bold.

5.0 5.0 12.9 5 1.9 73 4.0 57 2.0 25.0 0.07 11.0 198 9 16 0.9 53 37 3.0 48 3.4 22.0 0.05 14.0 185 12

179 166 131 500 980 700 118 0.7 513 700 200 200 150 700 150 300 200 100 533 290 184 3.7 1000 1000 700 100.0 100.0 700 1000 22947

28.0 individual element data in ppm).

70.0 22.0 560 375 70.0

5.8 3.6 25.0 120 120 0.1

49.4 1.7 31.9 12.5 67 12.5 31.9 49.4 1.7

5.0 2.6 3.9 10.6 0.9 253 0.5 215 5.0 2.6 0.5 253 0.9 10.6 3.9

50.0 70.0 8.0 67.1 70.0 70.0 1000 30.0 150.0 700 58.6

65 34 64 3.5 2.3 0.9 3.8 0.8 30 0.3 28 7 4.5 0.6 0.5 22 2.2 0.02 3 59 96 26.5 0.1 676 500 50.0 50.0 500 50.0 70.0 700 300 953 384 337 149 7.6 2.5 418 470 149 6.4 230 216 30.0 15.0 3.0 30.0 5.0 110 516 26.1 15.6 26.1 516 22.4 4.1 5.4 109 28 23.8 111 2.1 1000 Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Y Yb % $/ton

2 2 2 2 2 ects and Occurrences in Utah (all Type Type hort per ton based on REO prices from Table 1. Sandstone 51 Sandstone 51 Dome 155 Dome 155 Bonneville Gravel Bonneville Gravel Dike Black "Skarn" Th-bearing vein Gneiss & Pegmatite Permian Phosphorite Mississippian Phosphorite Phosphorite Mississippian Permian Phosphorite Permian Phosphorite

Rhyolite Breccia Rhyolite Fluorite Gneiss & Pegmatite? Gneiss Permian Phosphorite Be Ore Flow Dome

Mine Sheeprock Granite White Facies - Be Rosette 166 Mann-Longshot Ti-Zr Yellow Hammer Yellow Alteration "Pipe" Ibapah Armstrong - Iron Spring Iron Ore - Soil Ibapah Willard Northern Promontory Mtns Mississippian? Phosphorite 50.0 50.0 70.0 20.0 Little Green Monster Mississippian Cougar Spar Mine Fluorite - Soil Sample Honeycomb Flow Honeycomb Monroe Canyon Indian Springs Bench Ti-Zr Sandstone Pine Canyon Spor Mountain Eagle Rock - Spor Mtn NURE Soil Staats Crawford Mountains Permian Phosphorite Flaming Gorge Brush Creek Little Woodruff Creek North Fork, North Creek - Stream Rhyolite Sed. 110-Ft Adit - Ibapah Mine dump Mountains Weber Canyon Wasatch Paragneiss Laketown

Mineral Mountain Granite District W Skarn 307 Toms Creek - Ibapah Alteration Honeycomb Honeycomb Smelter Knolls Site Name Table 6. Geochemistry of REE Prosp Jurassic Intrusive Systems Cretaceous Fossil Placer Deposits Eocene Intrusive Systems

Miocene IntrusiveSystems Earth Crustal Abundance Utah NURE SS Threshold Paleoproterozoic Farmington Canyon Complex Oligocene Intrusive Systems Late Paleozoic Phosphorites

1. Estimated total value of REE in dollars s 2. The Permian phosphorite samples are listed from north to south. Pliocene Intrusive Systems

14 Figure 3. REE localities of Utah, with locations listed in order of appearance in text.

coarse quartz, plagioclase, and microcline, Canyon Complex in Devils Hollow about 5 and locally may contain biotite, , mi north-northwest of Morgan (figure 3, site garnet, muscovite, and/or magnetite (figure 13). This feldspar-quartz-muscovite 4). Note that the presence of garnet and pegmatite was prospected for (Buranek, muscovite indicate peraluminous conditions. 1942), but reportedly also has trace Th. Olson and Adams (1962) and Adams (1969) NURE stream sediment samples at this report that cyrtolite (a zircon that contains property are elevated, but not anomalous in LREE) is present in pegmatites in the Ce (94 ppm) and La (101 ppm). Farmington Canyon Complex southeast of Paleoproterozoic (1700 Ma) granitic Willard, Box Elder County. Adams (1969) pegmatite dikes and sills are also present in also notes that a prospect in migmatized the gneiss and schist terrane of the Welcome biotite gneiss in Arthurs Fork of Spring area (figure 3, site 14) of the Beaver Hardscrabble Creek, Morgan County, Dam Mountains in southwesternmost contains , molybdenite, monazite, Washington County (Biek and others, 2009). and xenotime (figure 3, site 12). NURE These white pegmatites are primarily stream sediment samples in Arthurs Fork composed of and quartz with have elevated or weakly anomalous Ce (147 minor muscovite, plagioclase, and garnet and ppm), La (185 ppm), and Y (43 ppm). commonly have graphic texture. As at Devils Another pegmatite dike cuts the Farmington Hollow, geochemically elevated, but not

15 A B

Figure 4. Closeups of Farmington Canyon Complex pegmatite. (A) Pegmatite boulder: very coarse-grained, cream-colored microcline, smoky gray quartz, very pale green plagioclase (altered), and minor limonite specks after pyrite. (B) Pegmatite boulder: white feldspar, smoky gray quartz, and dark clots of biotite-chlorite replacing red garnet. anomalous Ce (102 ppm) is reported from primarily in the Early Permian Meade Peak NURE stream sediments in this area. Phosphatic Shale Member of the Phosphoria The Devils Hollow pegmatite is on a and Park City Formations and to a lesser SITLA section (section 2, T. 4 N., R. 2 E. extent in the Early Mississippian Delle Salt Lake Base and Meridian (SLBM)). Phosphate Member of the Deseret Limestone Neither the exact location of the pegmatite and equivalent formations. The Meade Peak near Willard nor the Arthurs Fork prospect Phosphatic Shale Member is currently mined are documented. The Farmington Canyon for phosphate from four open-pit operations Complex prospects in these localities are in Idaho and one in northeastern Utah, north primarily the result of metamorphic of Vernal. segregation and not the more favorable zoned An underground mine in the Crawford pegmatites associated with alkaline intrusive Mountains (San Francisco Chemical Co.), complexes. Furthermore, the Willard and Rich County, east of Randolph was Utah’s Arthurs Fork REE prospects are unlikely primary source of phosphate from 1909 into targets for exploitation due to their small size, the late 1960s, prior to the opening of the environmentally sensitive location, and Brush Creek (Simplot Phosphates, LLC) proximity to residential development. SITLA open pit mine north of Vernal. The Crawford only controls a few scattered tracts in the area Mountains operation was closed in 1972. of these Farmington Canyon Complex The Brush Creek operation in Uintah County prospects. The area of the reported Welcome (9 ft at 24% P2O5) is Utah’s only current Spring pegmatites is all BLM-administered phosphate operation (figure 3, site 21). The land. mine produces roughly 3 to 4 million short tons of ore annually, which is processed into Upper Paleozoic Phosphorites 1 to 2 million short tons of phosphate concentrate. The concentrate is transported The Western Phosphate Field covers a as a slurry to the company’s Rock Springs, large area centered in southeastern Idaho and Wyoming, fertilizer plant via a 90 mi adjoining portions of Montana, Wyoming, underground pipeline. and Utah. The marine phosphate is present

16 As noted above, marine phosphorites 21, 28, and 29, T. 13 N., R. 6. E., SLBM). have been recognized as a potential source of SITLA also controls some surface and byproduct REE from phosphate operations mineral rights in an irregularly-shaped (Gulbrandsen, 1966; Jackson and (patented mining claims?) tract in sections 11 Christiansen, 1993). Apatite or fluorapatite and 12, T. 10 N., R. 7 E., SLBM in the are the primary phosphate minerals and are southern Crawford Mountains. However, any also known to host REE; loparite may also be SITLA property that is being considered for present. Various Utah phosphorite samples phosphate should be considered for REE. (table 6) are anomalous in Ce, Dy, Er, Eu, Gd, Ho, La, Nd, Sm, Y, and Yb. Most of the Jurassic Intrusive Systems phosphorite REE analyses are relatively enriched in HREE. The highest recorded Gold Hill, Tooele County TREO in the phosphorite samples is from an old, small mine in Rich County near the south The Gold Hill mining district lies near the end of Bear Lake, east of Laketown (figure 3, Nevada state line in west-central Tooele site 22). A sample of the Delle Phosphate County (figure 3, site 31). Gold Hill is a Member from this property reported roughly significant district, being both the largest As 0.43% TREO (table 6). Overall, the and W producing district in the state. The phosphorite samples in northern Utah (Rich Gold Hill district is structurally very complex County) appear to have the highest levels of and hosts an unusual suite of ore deposits REE and phosphate, including Laketown (3 ft including skarn, vein, replacement, and at 28% P2O5), Crawford Mountains (7 ft @ polymetallic pipe-like deposits. Most of the 31% P2O5), and Woodruff Creek (Gere, ore deposits in the district are associated with 1969). None of the known REE samples the large (22 sq mi) Jurassic plug from the Western Phosphate Field is (about 152 Ma). The granodiorite is suggestive of a standalone REE operation, lavender-gray, medium- to coarse-grained, but REE could potentially be recovered as a and equigranular to locally porphyritic. The byproduct from a large scale phosphate primary minerals are plagioclase, perthitic operation. orthoclase, quartz, hornblende, and biotite The Little Green Monster mine in the with accessory apatite, magnetite, and titanite southern Oquirrh Mountains of Utah County (Nolan, 1935; Robinson, 1993). is hosted in an unnamed shale in the Upper The northern Deep Creek Range shows Mississippian upper limestone member of the some evidence of modest westward rotation. Great Blue Limestone. The mine was The oldest rocks in the area are Early operated from 1894 to 1911 for variscite [Al Cambrian Prospect Mountain Quartzite on (PO4)2(H2O)] and then briefly during 1959- the east flank of the range, stepping upward 60 for Sc (Shubat, 1988). However, while through the section to Permian carbonates on the variscite is anomalous in Sc (about 650 the west. Eocene volcanic rocks also occur ppm), it is not notably enriched in REE (table on the west side of the range. The Jurassic 6) (Shubat, 1988; Peter Hahn, 2011, written granodiorite plug intrudes the lower communication). Paleozoic rocks near the eastern range front. SITLA tracts are not involved in the The southern Deep Creek Range (see Ibapah current Utah phosphate operation. An batholith section below) also appears to have irregular 445-acre SITLA tract lies on trend, been rotated westward. but across a major fault, about a mile north of The pipe-like bodies are small, irregular, the Laketown phosphate mine (sections 20, sub-vertical, W-Cu-Mo-bearing chimneys of

17 coarse-grained actinolite-orthoclase- La at the Rustler and Atlantis mines in the tourmaline formed within the Jurassic same section of the district. Several other granodiorite. The polymetallic skarns (Cu- samples on the west flank of the granodiorite W-As) form in carbonates adjacent to the plug have elevated to weakly anomalous La granodiorite stock and occur as prograde (70 to 200 ppm) (table 6). garnet-diopside and retrograde hornblende- A swarm of north-northeast-striking, actinolite-tourmaline skarns. The largest moderately west dipping quartz-adularia- historical producers in the district are the calcite veins (Miocene?) cut through the arsenopyrite [FeAsS] polymetallic vein and middle of the granodiorite, primarily on the replacement deposits (Gold Hill and United east side of Rodenhouse Wash. The veins States mines) formed in the Mississippian extend intermittently for approximately 2 mi Ochre Mountain Limestone near the Jurassic in a zone generally 500 to 1000 ft wide from granodiorite. These bodies (As-Pb-Cu) lie just east of the Climax mine on the north. just outboard of the skarns and are controlled The veins range from a few inches to up to 40 by the intersection of mineralizing fissures ft or so thick and carry erratic Be and favorable host beds (Nolan, 1935). mineralization. The Be averages roughly 200 The pegmatitic pipe-like deposits hold the ppm and may occur in bertrandite or may be most interest for REE. These deposits substituting into the adularia. No notable reportedly include the Yellow Hammer and REE are reported on the few assays available Reaper mines and possibly the smaller from the Rodenhouse Be prospects, but Centennial, Doctor, and Enterprise properties additional work could be done, given the in the Clifton (southern) subdistrict (Nolan, geochemical association of these elements 1935). Nolan (1935) describes the pipe-like (El-Shatoury and Whelan, 1970; Whelan, deposits as small, tubular, coarse-grained 1970). masses of altered granodiorite, formed at The Yellow Hammer mine lies in a large structural intersections with poorly defined block of patented mining claims. Various margins. The deposits are principally SITLA sections cover portions of the large composed of perthitic orthoclase, Na-rich Jurassic granodiorite plug. The majority of actinolite (pargasite), albite, tourmaline, the land in the area is controlled by the U.S. sericite, chlorite, and calcite. The primary Bureau of Land Management (BLM) and an ore/metallic minerals are , assortment of patented claims. No SITLA molybdenite, chalcopyrite, pyrite, magnetite, tracts occur in the Rodenhouse Be area. and specularite. The minerals are locally very coarse grained with Nolan (1935) Granite Peak, Tooele County reporting actinolite to 4 ft long, orthoclase a foot long, and scheelite 4 inches long. Granite Peak is an isolated mountain Accessory minerals include apatite, allanite, located in the Great Salt Lake Desert of west- titanite, and zircon. Some of the minerals are central Utah, about 30 mi east of Gold Hill reminiscent of REE deposits, including the (figure 3, site 32). Granite Peak is principally Na-rich actinolite and albite and the composed of an exposed 25 sq mi Jurassic accessory allanite, titanite, and apatite, which (about 149 Ma) granite-granodiorite complex can all be REE-bearing. (Clark and others, 2009). The upper part of Zimbelman and others (1991) report the complex is a foliated granodiorite strongly anomalous La (500 ppm) at the underlain by a more leucocratic granite. Both Yellow Hammer mine and a mile to the north intrusive phases are cut by pegmatite and at the Copper Bloom prospect and 150 ppm aplite dikes and quartz veins. Clark and

18 others (2009) did not directly date the pegmatite dikes, but infer that they are related Cretaceous Fossil Placer Deposits to the leucogranite intrusion and are Late Jurassic in age. There are several recognized Late Pegmatite dikes are common throughout Cretaceous fossil beach placer deposits on the the Granite Peak intrusive complex and are Colorado Plateau of south-central Utah that estimated to form up to 10 to 15% of the have primarily been investigated as a source intrusive rock volume, being more prevalent of Ti-Zr. The deposits cluster in four areas: in the upper foliated granodiorite. The Straight Cliffs, Garfield County; Fiftymile pegmatite dikes typically strike Mountain, Kane County; Indian Springs approximately N. 35° E. and dip 55° to 70° Bench, Garfield County; and Coal Cliffs, W. The pegmatites range from small Emery County (Dow and Batty, 1961; stringers, to pods, to larger tabular, zoned Adams, 1969). During the Late Cretaceous dikes with some individual dikes up to half a (about 83 Ma) central Utah was situated mile in length. The pegmatites are composed between the Sevier highlands to the west and of coarse aggregates of quartz, microcline, the Western Interior seaway to the east plagioclase, and muscovite. Accessory (Hintze and Kowallis, 2009). minerals generally constitute about 1% of the pegmatites and include garnet, tourmaline, “At least 14 -zirconium beryl, samarskite, zircon, apatite, and bearing heavy mineral occurrences are hematite (Fowkes, 1964). known in the Kaparowits Plateau region Fowkes (1964) reports three zones within of southern Utah. The occurrences are the pegmatites: borderwall, intermediate, and fossil beach placers in the John Henry core. Samarskite and beryl occur in greatest Member of the Cretaceous Straight abundance at the inner margin of the Cliffs Formation. They occur at several intermediate zone, adjoining the quartz- stratigraphic horizons and most are at dominant core. The core is reportedly 97% the top of thick, fine-grained, quartz and 2% microcline (Fowkes, 1964). transgressive-regressive marine The Desert Queen prospect on the west side sandstone sequences. The heavy of Desert Peak was briefly examined by the mineral zones are elongate lenses, Mica Corporation of America in the 1940s generally 100 to 300 ft wide, 200 to for muscovite with some books up to 6 inches over 4500 ft long and from 4 to over 12 across. ft thick. Typically, they can be Three very approximately located NGDB subdivided into three vertical zones samples in the Granite Peak general area representing upper shore face, foreshore report anomalous LREE: Ce, Eu, and Nd. and possibly also back shore No NURE samples in the Granite Peak area environments. Zones include a lower are anomalous in REE. zone of white friable cross-bedded The Granite Peak area pegmatites are sandstone (3 to 8% heavy minerals), a potential, but unlikely sources of REE. The middle zone of red to brown, area is part of the U.S. Army Dugway horizontally bedded sandstone (20 to Proving Grounds and no SITLA mineral 60% heavy minerals-quite variable) and sections are of notable interest. an upper maroon to black strongly cemented massive sandstone (30 to 60% heavy minerals). The black consist predominately of zircon and

19 various titanium-bearing minerals Mountain Ti-Zr sandstones, samples of an (ilmenite, lucoxene, -, ilmenite concentrate test sample reported in rutile) with subordinate heavy mineral the UGS files show 0.17% Nb2O3, 0.03% silicates, oxides, and Y2O3, and 0.09% CeO2. The Mann-Longshot phosphates” (Gloyn and others, 1997). deposit is estimated to contain approximately 300,000 short tons averaging 3.0% ZrO2 and There are two recognized clusters of Ti- 9.6% TiO2 (Gloyn and others, 1997). The Zr deposits in the Kaparowits Plateau: Fiftymile Mountain Ti-Zr deposits, also lie Straight Cliffs and Fiftymile Mountain within the Escalante – Grand Staircase (figure 3, sites 41 and 42). The Straight National Monument. Cliffs Ti-Zr deposits in central Garfield Another Late Cretaceous Ti-Zr fossil County are within a regressive sequence from beach placer lies on the southwest flank of an underlying shallow marine sequence the Mount Hillers laccolith in the southern grading upward to a non-marine, lagoonal Henry Mountains, Garfield County (figure 3). section, including the Alvey coal seam. The The Indian Spring Bench Ti-Zr deposit host sandstone is believed to represent a occurs near the top of the Ferron Sandstone barrier-island environment. The Calf Canyon member of the Mancos Shale. The deposit is deposit is about 6 mi due south of Escalante flat lying and is elongated to the north- and the Dave Canyon deposit adjoins it to the northwest over a length of 1560 ft with south. Crudely estimated average grades widths of 100 ft and an average thickness of 3 from surface rock chip samples for these ft. The mineralized zone contains ilmenite, deposits run from about 7 to 15.8% ZrO2 and zircon, magnetite, and monazite in a 11.85 to 20.9% TiO2 (Doelling, 1975; Gloyn hematitic cement. Samples average 1.5% and others, 1997). A bulk sample of this ZrO2, 25.5% TiO2, 15.4% Fe, 0.21% ThO2 deposit had grades of 12.4% ZrO2, 18.8% equivalent, and 0.003% Sc (Dow and Batty, TiO2, and 14.7% Fe (Dow and Batty, 1961). 1961; Doelling, 1975). Given the high Th Two channel samples of the deposit by content (presumably in monazite), this Doelling (1975) ran 0.09 and 0.15% Th prospect could potentially carry up to 1% equivalent. Gloyn and others (1997) suggest TREO. NGDB samples of black sandstones the Calf Canyon deposit may host over on the Indian Spring Bench have strongly 300,000 short tons of Ti-Zr ore. No REE anomalous La (1000 ppm) and Y (1500 ppm) values are available for the Straight Cliffs Ti- in addition to Zr, Sc, and Nb (table 6). The Zr deposits and they all lie within the Grand exact location of this deposit is uncertain, but Staircase - Escalante National Monument. it appears to lie on BLM ground; possibly in A second cluster of Ti-Zr deposits occurs sections 17-20 or 29-30, T. 34 S., R. 11 E., on Fiftymile Mountain, Kane County. The SLBM; just southwest the Mount Hillers Mann-Longshot deposit is the largest known Wilderness Study Area. These six sections deposit in this group which essentially lie are all BLM-administered lands. along strike of the Calf and Dave Canyon Another Late Cretaceous Ti-Zr heavy deposits and about 26 mi to the south- mineral accumulation occurs near the base of southeast of them in Kane County. The the Ferron Sandstone member of the Mancos heavy minerals are rutile, ilmenite, zircon, Shale in the Coal Cliffs area, Emery County monazite, allanite, and apatite. Doelling and (figure 3). A series of poorly described, Davis (1989) report anomalous Au assays northwest-trending deposits are exposed as from these deposits. Although no REE lenses of ilmenite, zircon, magnetite, and values are available for the Fiftymile monazite in hematite-carbonate cemented

20 sandstone. The deposit is estimated to The Ibapah batholith extends completely contain 115,000 short tons, and an average across the range in a 6-mi-wide swath from grade of three samples from this deposit is west to east, covering a total of 1.8% ZrO2, 12.6% TiO2, 33.4% Fe, and approximately 55 sq mi. Both the northern 0.10% ThO2 equivalent (Dow and Batty, and southern contacts of the batholith are 1961). If the Th content were contained in believed to dip steeply south (Bick, 1966). monazite, this prospect could also potentially The intrusive is generally a light-gray, carry up to 1% TREO. No REE geochemical coarse-grained, weakly porphyritic, data are available for the Coal Cliffs Ti-Zr peraluminous quartz monzonite or deposits, but like the other Late Cretaceous monzogranite. The primary minerals are fossil beach placer deposits, these sandstones quartz, microcline, plagioclase, and biotite are likely to have elevated REE values. This and/or muscovite, in various phases. The deposit reportedly lies on BLM ground in accessory minerals include magnetite, sections 18, 19, 29, 30, and 32, T. 22 S., R. 7 allanite, titanite, zircon, monazite, apatite, E., SLBM. and thorite. The stock is texturally homogeneous except that it is finer grained Eocene Intrusive Systems near the crest of the range (at approximately 12,000 ft elevation), possibly due to a Ibapah Batholith, Juab County shallower emplacement depth, proximity to the upper contact of the batholith, or both The Ibapah batholith is located in the (Wallace, 1986; Nutt and others, 1990). southern Deep Creek Mountains of extreme Structural offset of contacts across the northwestern Juab County, about 20 mi south batholith suggests that the batholith was of Gold Hill (figure 3, site 51). The Deep emplaced into a major pre-existing easterly Creek Mountains show evidence of mid- trending structure (Bick, 1966). The age of Tertiary westward rotation, as the batholith is in doubt with ages ranging Neoproterozoic McCoy Creek Group from Cretaceous to Miocene, but is believed metasedimentary rocks are exposed on the to be about 39 Ma (Nutt and others, 1990). east flank of the range and moderately west- Pegmatite and aplite dikes ranging from dipping (20° to 45°) Paleozoic sedimentary an inch to several ft in width are found rocks are to the west. This pattern is throughout the granite, and in the reinforced by mapping of the hydrothermal metasedimentary rocks near its southern mineral deposit zoning in the range that contact. In addition, northwesterly trending shows hypothermal deposits on the east, dikes occur in the eastern and southern mesothermal deposits in the middle, and portions of the Ibapah batholith (Wallace, epithermal deposit in the west (Thomson, 1986). The pegmatite dikes consist of coarse 1973). In addition, mapping by Wallace of quartz, orthoclase, plagioclase, (1986) shows that the eastern contact of the muscovite, beryl, apatite, zircon, garnet, and batholith (at an elevation of approximately pyrite. The pegmatites are roughly zoned 5300 ft) has been strongly sheared, indicating with an outer zone of graphic granite; an significant upward displacement along the intermediate zone of orthoclase, muscovite, east range front fault, which is also suggested and quartz; and cores of vuggy gray and by the strong gravity low in the Snake Valley white quartz containing beryl crystals to the east. The northern end of the Deep (Thomson, 1973). Creek Range (see Gold Hill section above) A 2.5-sq-mi area centered on Toms Creek also appears to show westward rotation. in the northeast quadrant of the Ibapah

21 batholith has been pervasively altered with consists of contact metamorphosed McCoy hematite along microfractures. In addition, Creek Group metasedimentary rocks with some of the primary biotite in this zone has finely disseminated sulfides (pyrite and/or been altered to chlorite and magnetite and the pyrrhotite). An aeromagnetic survey have an orange Fe oxide haze suggests that the south margin of the (Wallace, 1986). This zone is weakly batholith extends beneath Red Mountain. anomalous in Au, Ag, Be, Bi, Pb, Mo, Sn, The area is reportedly weakly anomalous in and W (Nutt and others, 1990). One NGDB Ag, Cu, Zn, Mo, and Sn (Nutt and others, sample in the Toms Creek alteration zone is 1990). Thomson (1973) reports trace Au and anomalous in Ce, La, Nd, and Pr (table 6). Ag from a 2 ft sample of a Mn-stained The southern flank of the Ibapah batholith in the Red Hill adit on the north coincides with a series of mineralized zones, flank of Red Mountain and Bullock (1981) including the Trout Creek area on the east, reports native gold from this prospect. The the Red Mountain alteration zone near the Red Mountain alteration zone is slightly apex of the range, and the Queen of Sheba anomalous in Sc (20 to 22 ppm). mine area on the west side of the range. The The Queen of Sheba, Jumbo, and One south flank also includes small plugs of Hundred and Ten-Foot adit Au-Ag properties alaskite and also aplite and pegmatite dikes. lie on the west flank of the Deep Creek The Trout Creek district is centered on a Mountains, south of the Ibapah batholith. series of alaskite sills (0.2 sq mi) in domed The Queen of Sheba was the largest mine in Proterozoic metamorphic rocks which have the area having produced roughly 5000 been thrust over Middle Cambrian units (Nutt ounces of Au and 8800 ounces of Ag. and others, 1990). The alaskite sills, vary Mineralization occurs as high-grade Au-Ag from aplite to coarse-grained pegmatite, are veins in McCoy Creek Group quartzite-schist commonly foliated along their contacts, and associated with pegmatite and alaskite dikes. are primarily composed of quartz, potassium One dump sample from the One Hundred and feldspar, muscovite, garnet, and locally Ten-Foot adit analyzed by semi-quantitative biotite (Nutt and others, 1990). emission spectrography reported 6000 ppm Y Mineralization occurs as greisen-like veins and 17,000 ppm Zr (table 6) (Satkoski and and carbonate replacement/skarn deposits in Sokaski, 1980). Seven other samples were the Late Proterozoic dolomite surrounding collected from the One Hundred and Ten- the small alaskite plug (Nutt and others, Foot adit and dump, but none of the other 1990). Mineralization consists of quartz, assays approached these values. fluorite, scheelite, beryl, sphalerite, calcite, The Goshute Quartz mine is and muscovite. Geochemical sampling located within the batholith, about 1.8 mi shows sporadic ore-grade W, Zn, and Be, and north of the Queen of Sheba. The mine is geochemically anomalous Au, Ag, Bi, Cd, developed on a small pegmatite in Dads Cu, F, Pb, Mo, Sn, and Hg (Thomson, 1973; Creek canyon. The mine was apparently an Hannigan, 1990; Nutt and others, 1990). No unsuccessful attempt to mine piezoelectric REE analyses are known from this area, but quartz crystals from the pegmatite; probably the W-Be-F-Mo-Sn suite seems compatible during World War II. Beryl (aquamarine) is with elevated REE. also reported from the Goshute pegmatite The Red Mountain alteration zone (Satkoski and Sokaski, 1980). The Birch underlies Red Mountain (elevation 11,500 ft) Creek pegmatite prospect occurs about 2.7 mi on the south flank of the Ibapah batholith. to the north-northeast of the Goshute mine. The roughly 0.5 sq mi alteration zone

22 Neither of these pegmatites is known to have approximately 130 million cubic yards or 225 been analyzed for REE. million short tons (using a tonnage factor of The Quaternary gravels (from 16 cu ft per short ton). An unrepresentative approximately 6200 to 7200 ft elevation) on sample collected in a modern drainage both the west and east sides of the Ibapah cutting the Bonneville gravel reported by batholith have been examined for U and Th Cadigan and others (1979) has elevated REE placer accumulations. On the west side of (table 6). Great Western Minerals Group the range an area in southeastern Deep Creek Ltd. acquired this area as a REE property in Valley, south of the town of Ibapah, has been 2008 and report grades up to 0.8% TREO identified as containing radioactive black plus high Fe contents for select surface and anomalous U in stream sediment samples; however, grades average closer to samples (Satkoski and Sokaski, 1980). This 0.1% TREO. The project has been dormant area coincides fairly well with a mapped for the last two years due to lack of alluvial fan, primarily in the area of Steves exploration risk capital. Creek, Dads Creek, and lower Fifteenmile Most of the Ibapah batholith related REE Creek. The anomaly covers an area of analyses have a high LREE/HREE ratio; i.e., approximately 3.5 sq mi in sections 15, 16, they are relatively enriched in LREE. 20, 21, 22, 27, and 28, T. 11 S., R. 19 W., The only SITLA tracts in the area of the SLBM. A bulk sample of this sand contained Ibapah batholith are in the area of Glacial 170 ppm U and 260 ppm Th. Monazite and Lake Bonneville beach gravels on the east euxenite are believed to be the source of the flank of the range. The most favorable anomaly (Satkoski and Sokaski, 1980). No SITLA parcel (about 773 acres) is section 32, REE data are known for the Deep Creek T. 11 S., R 17 W., SLBM and an adjoining Valley black sand area. 44 acre parcel in SE ¼, SE ¼, section 31. The Pleistocene Glacial Lake Bonneville The Trout Creek district is primarily on beach gravels on the east flank of the Ibapah patented mining claims and BLM ground. batholith in Snake Valley have also been The Deep Creek Valley black sand area, evaluated for placer U and Th. The beach Queen of Sheba area, and western pegmatites placer occurs in Lake Bonneville terrace are on the Goshute Indian Reservation. The deposits between elevations of approximately Toms Creek and Red Mountain alteration 5200 ft and 5040 ft. Heavy mineral zones are in BLM’s Deep Creek Mountains concentrates from the placer include Wilderness Study Area. magnetite, zircon, monazite, titanite, xenotime, allanite, thorite, ilmenite, and Lucin District, Box Elder County hematite. In addition to low levels of U, Th, Ti, and Zr, these bleach placer concentrates The Lucin mining district lies in the also have elevated Nb and REE, including northern Pilot Mountains in southwestern Ce, La, Y, and Yb (Cadigan and others, Box Elder County (figure 3, site 52). 1979). This area averages about 3000 ft wide Mineralization was initially discovered in the by 40,000 ft long. Because of the Lucin district in 1868. Production was fairly geologically fleeting nature of Glacial Lake continuous from the completion of the Bonneville (the highest Bonneville shoreline transcontinental railroad until the 1920s, and level was only reached for a period of then intermittent until 1963. Lucin’s total approximately 1000 years about 15,000 years production is about 171,000 short tons of ago) the deposit is unlikely to average much predominantly Cu and Pb ore containing over 30 ft thick, suggesting a total volume of minor Ag, Zn, Fe, Au, and possibly Mo

23 (Doelling, 1980, 2006). The district was ilmenite per cubic yard of alluvium with intensely explored for both Cu and Au-Ag magnetite and some zircon (Doelling, 1980). mineralization from the early 1980s to the Assuming about 1.5 short tons per cubic yard late 1990s by a series of mostly junior of dry sand and 32% Ti in ilmenite we can companies. Pilot Exploration concentrated calculate a grade of very approximately 1.6% on porphyry Cu/skarn mineralization near Ti. Although no REE are reported for this Copper Mountain. Then in the 1990s, Lexam area, elevated values would be expected. Explorations (who held partial mineral rights SITLA section 36, T. 7 N., R. 19 W., to the Central Pacific railroad checkerboard SLBM ; section 32 T. 7 N., R. 18 W., SLBM; lands) did considerable exploration for Au in and section 2 T. 6 N., R. 19 W., SLBM are the Pilot Range and areas to the west in located in this black sand area and may have Nevada (Limbach, 1992, 1997, and 1998, some Ti and REE potential. unpublished Lexam Explorations data in UGS files). Duval International Corp. did Oligocene Intrusive Systems work about 5 mi east of the main Lucin district on a sedimentary rock-hosted Au Washington District, Beaver County target near Lion Hill in the early 1980s. This area was reexamined by Santa Fe Pacific The Washington district is located in the Mining in the early 1990s. Indian Peak Range, southwestern Beaver The Lucin district is geologically County (figure 3, site 61), and has been a complex, being underlain by a large slide modest producer of fluorite (about 20,000 block of generally north-striking, moderately short tons), with lesser Pb and Zn production. east-dipping Paleozoic sedimentary rocks The bulk of the fluorite production, about sitting in low-angle fault contact on top of the 80%, has come from the Cougar Spar mine. shallow dipping, Eocene (39 Ma) McGinty The Indian Peak Range was rotated eastward monzogranite (Miller and others, 1993). The during the Oligocene-Miocene so that the majority of the Lucin district’s production mid-Oligocene volcanic rocks dip moderately was from the Copper Mountain and Tecoma eastward, but mid-Miocene volcanic rocks Hill mines in the Regulator Canyon area near are relatively flat. the center of the district. The mineralization The host rocks at the Cougar Spar fluorite at Copper Mountain is zoned from a central deposit are primarily Oligocene Wah Wah Cu-Fe sector near the crest of the range to Springs Formation dacitic ash-flow tuffs Pb-Zn-Ag mineralization along the slopes. intruded by a large plug of essentially coeval Farther outward from these mineral zones, granodiorite porphyry (about 30 Ma). These the district hosts extensive jasperoid breccias units are cut by a series of narrow (about 15 and subeconomic distal-disseminated Au-Ag ft thick), N. 65º E.-trending, steeply north- occurrences. dipping rhyolite porphyry dikes (Best and The pediment east of the main exposure others, 1987). The rhyolite dikes contain of monzogranite on the east flank of Copper accessory fluorite, secondary biotite, and Mountain hosts reported Quaternary Ti heavy fine-grained disseminated pyrite (5%). mineral sand. The black sands result from Limited lithogeochemistry on the dikes the weathering and transportation of the suggest they are alkali-rich, high-silica heavy minerals from the monzogranite. The rhyolite containing greater than 75% SiO2 heart of the black sands area (township and about 5% K2O (Grant, 1979). corner T. 6 and 7 N., R. 18 and 19 W., Mineralization occurs primarily as north- SLBM) averages about 150 pounds of northwest-trending fluorite-quartz-calcite

24 veins and breccias. Mineralization is The property lies on the east end of an probably related to the rhyolite porphyries, easterly trending, Miocene lineament from which are believed to be about 20 Ma, but Pine Grove (23 Ma) on the west, through the some veins are in faults that cut the porphyry Moscow stock (22 Ma), Granite district (25 dikes. The fluorite veins range from narrow to 18 Ma), Newton district (18 Ma), and seams to veins up to 8 ft wide. district (14 Ma). The Pine World-wide, fluorite occurs at several of Canyon mineralized area is centered on a the known REE producing properties (see small, Miocene (24.4 Ma), peralkaline, Important REE Deposits section above). One micromonzonite pluton that intrudes a NURE soil sample (table 6), with reported sequence of Oligocene-Miocene, calc- mining contamination, near the Cougar Spar alkaline andesite to rhyodacitic volcanic mine indicated weakly anomalous REE: Ce rocks of the Marysvale volcanic field. The (149 ppm), Eu (5.8 ppm), Lu (0.9 ppm), and micromonzonite is part of a breccia pipe (0.2 Yb (11.7 ppm). The NURE sample is also sq mi) that contains some very unusual black, anomalous in Li (119 ppm) and Sn (15 ppm). skarn-like aluminous and -rich bodies. The sample is probably contaminated from The black aluminous skarn-like rocks contain the onsite fluorite flotation mill tailings. , spinel, diaspore, zirconolite and Mineralization at more well documented accessory REE-bearing hibonite, fluorite mines in the area (Staats mine, Blawn [CaTiO3], [(Mg,Fe)Ti2O5], and Mountain district) contains the accessory pseudobrookite [Fe2(Ti,Fe)O5]; the rocks are phosphate minerals [Ca(UO2)2(PO4) reportedly anomalous in REE (table 6) 2·2-6(H2O)] and (Bullock, (Agrell and others, 1999). The Pine Canyon 1981). Similar phosphate minerals at the REE assay has a high LREE/HREE ratio, that Cougar Spar mine could contain REE. The is, it is relatively enriched in LREE. Cougar Spar REE analysis has a high LREE/ The property lies on the boundary HREE ratio, suggesting it is relatively between the U.S. Forest Service to the west enriched in LREE. and BLM controlled ground to the east. No The Cougar Spar fluorite mine is on a SITLA tracts lie near the Pine Canyon block of three patented claims and an breccia pipe. adjoining 0.5 sq mi area of fee land surround by BLM-administered ground. SITLA has Intrusive Complexes of the Colorado peripheral tracts (section 2 and 16, T. 30 S., Plateau R. 18 W., SLBM) to the southwest and northeast of the Cougar Spar area. The Henry, La Sal, and Abajo Mountains are all cored by large, Oligocene (32 to 23 Pine Canyon, Piute County Ma) laccoliths and there are similar intrusive rocks farther south along the Arizona border The peculiar black “skarns” of Pine at Navajo Mountain and Comb Ridge. Early Canyon lie on the eastern flank of the Sevier intrusions in these igneous complexes Plateau in east-central Piute County (figure 3, typically range from calc-alkaline to mildly site 62). The property was reportedly alkaline and monzonite stocks. discovered by an LDS polygamist hiding Younger alkaline syenite or peralkaline from the U.S. marshal in Pine Canyon. The granite porphyry stocks, dikes, and breccia property was first examined by the U.S. bodies are reported from Mount Pennell in Bureau of Mines in 1945. No mining has the Henry Mountains, North Mountain in the taken place on the property. La Sal Mountains, and Navajo Mountain.

25 Minor peralkaline rhyolite and nosean more extensive northeast-trending Iron Axis trachyte porphyry dikes occur at North mineral belt. The Sevier thrust system in the Mountain and dike-like kimberlitic breccias Iron Springs area had its major thrust plane are reported from Moses Rock and Mule Ear located above the massive Navajo Sandstone on Comb Ridge (Mutschler and others, within the relatively incompetent beds at the 1997). Despite the presence of apparently base of the overlying Carmel Formation. favorable intrusive suites, no anomalous REE This thrust fault and an associated anticline minerals or geochemical values have been helped localize the laccoliths (Mackin, 1968; recognized associated with these intrusions Bullock, 1970). The porphyritic quartz (Lipman, 1987; Nelson and Davidson, 1997). monzonite is pink-gray, fine-grained quartz and K-spar with plagioclase and Miocene Intrusive Systems hornblende, augite, and biotite with accessory magnetite, ilmenite, apatite, titanite, and Iron Springs, Iron County zircon. There are three basic Fe ore types: veins, The Iron Springs mining district is the breccia bodies, and replacement ore bodies. most productive Fe district in the western The veins are the least important and United Stated (about 100 million short tons primarily occur in radial and concentric of Fe ore) and still hosts significant Fe fractures/joints in the quartz monzonite resources (figure 3, site 71). The Fe content laccoliths. About a third to half of the altered of the ore has historically averaged about joints in the intrusive contain some magnetite 50% Fe. The Fe ore deposits were first with accessory hematite, apatite, calcite, discovered by Mormon scouts in 1849, with pyrite, and pyroxene (Bullock, 1970). These pioneer production lasting until 1876, veins range from a few inches to over 10 ft yielding about 425 short tons of pig iron wide, with most of the larger veins in radial (Mackin, 1968). Ore production then halted joints. The veins occasionally display coarse, until 1923, when the Columbia Iron Mining euhedral magnetite and apatite crystals. Company, a subsidiary of U.S. Steel, began Bullock (1970) suggests that some of the the first large-scale operations at the north larger veins host potential bodies of up to end of Granite Mountain. Production 100,000 short tons. The Great Western mine continued until 1980, and then resumed on a on the southwest side of the Three Peaks smaller scale by Geneva Steel from 1987 to laccolith was believed to be the largest vein 1995. Efforts currently are continuing to deposit in the district. renew production based principally on the Breccia ores occur as irregular bodies in proven open pit resource of 28.4 million short premineral fault zones, adjoining replacement tons of 48.6% Fe at the Comstock/Mountain ores, and as collapse pipes within the quartz Lion. monzonite. Breccia ores represent some of The Iron Springs ore bodies are the largest ore bodies including the Blowout associated with three oval-shaped Miocene mine and portions of the Rex, Lindsay, and (about 22 Ma) calc-alkaline porphyritic Comstock ore bodies (Bullock, 1970). quartz monzonite laccoliths, from southwest The largest and most important ore bodies to northeast: Iron Mountain (5.9 sq mi), are stratabound replacement ores in the Granite Mountain (2.9 sq mi), and Three Middle Jurassic Homestake Limestone Peaks (7.5 sq mi). The three laccoliths occur Member of the Carmel Formation along a slightly arcuate, 20-mi-long surrounding the laccoliths. The replacement northeast-trend that represents the heart of the ore bodies are tabular, pod-shaped deposits in

26 limestone along the igneous contacts, southeast of Monroe, Sevier County (figure coinciding with zones of strong jointing in 3, site 72). The steeply dipping vein occurs the underlying quartz monzonite. In form, in an area of late Oligocene andesitic the replacement deposits resemble skarns, but volcanic rocks (~25 Ma) which are intruded their general lack of calc-silicate by Miocene quartz monzonite porphyry plugs development has resulted in the deposits (22 – 21 Ma) (Hintze and others, 2003). The being referred to as replacement bodies. The quartz-microcline vein contains minor principal gangue minerals are calcite, apatite, muscovite, goethite, jarosite, lepidocrocite quartz, and muscovite (Wray and Pedersen, [FeO(OH)], and . NGDB samples in 2009). The Comstock-Mountain Lion the Monroe Canyon area collected by Staatz deposit is a prime example of the stratabound (table 6) are strongly anomalous in Th (1500 replacement type deposit (Bullock, 1970). ppm) and the LREE Ce (1000 ppm), Nd (700 Apatite is the primary known REE- ppm), Pr (150 ppm), and Sm (100 ppm). The bearing phase in the Iron Springs ores and exact location of the Th-REE-bearing vein is apatite is more common in the veins. Adams somewhat uncertain, but nearly all of the (1969) reports REE-bearing apatite from the ground in the area is administered by the U.S. Smith Fe mine on the southern flank of the Forest Service except for some fee ground in Three Peaks laccolith. Historic concentrate the valley bottom near the mouth of the production has averaged about 1 weight (wt) canyon. % apatite or about 0.42% P2O5, but rare individual ore assays show as much as 7.8% Spor Mountain, Juab County P2O5, equivalent to over 18 wt % apatite. Since phosphate is a deleterious constituent The Spor Mountain mining district, the for steel making, it is possible that some of world’s premier Be producer, lies on the west the existing dumps may contain high P2O5 flank of the Thomas Range in west-central grades. Barker (1995) reports strong REE Juab County (figure 3, site 73). The values in apatites from the veins including operation’s Be production is estimated at 13,400 ppm Ce, 280 ppm Dy, 107 ppm Er, over 3 million short tons of ore averaging 45.8 ppm Eu, 510 ppm Gd, 55.6 ppm Ho, about 0.23% Be has been mined from 10 5820 ppm La, 10.4 ppm Lu, 5950 ppm Nd, small to medium sized open-pits in the Spor 1560 ppm Pr, 821 ppm Sm, 18.9 ppm Tm, Mountain district since production began. and 93.6 ppm Yb. In addition, a few NURE This would amount to about 12.8 million and NGDB samples report weakly anomalous pounds of recovered Be, which, at roughly Ce, Eu, Gd, La, and Nd from the Iron Springs $100 per pound Be, would be valued at very district (table 6). The Iron Springs REE approximately $1.28 billion in Be metal analyses are strongly enriched in the LREE. production, making Spor Mountain roughly Several partial SITLA sections are the seventh-most productive mining district present in the Iron Springs mining district. In in Utah. Current production averages large part, these tracts are incomplete due to approximately 51,000 short tons of ore per the presence of patented mining claims which year. In 2010, proven reserves were reported appear to cover the more favorable ground as about 6.404 million short tons averaging for Fe resources. 0.266% Be with another 3.519 million short tons of 0.232% Be probable (Materion Corp., Monroe Canyon, Sevier County 2010, annual report). The first mineralization discovered in the Staatz (1974) reports a Th-bearing vein in district was fluorite located on Spor Monroe Canyon approximately 2 mi

27 Mountain by George Spor and sons in 1943. generally small diameter, very steeply east- Later that decade, additional fluorite deposits plunging breccia pipes related to faults and were discovered and production ramped up. small rhyolitic intrusive bodies (Staatz and In 1953, U was discovered in The Dell, the Carr, 1964). Nearly all of the pipes are property was leased to Uranium carrot-shaped, becoming smaller at depth. Company (Richard D. Moody) in 1956, and Low-grade U occurs in the fluorite pipes and production began a few years later. the pipes shows a gradual increase in U grade Ultimately the district proved to be a small U from the northern portion of the district towar producer (about 420,650 pounds U3O8), but the south, toward Eagle Rock Ridge (Sharp, the productive fluorite district in Utah (about 1963). The small Yellow Chief U mine 350,000 short tons of >60% fluorspar) produced modest quantities of low-grade, U (Lindsey, 2001). mineralization from a series of Oligocene (?) Beryllium was discovered in 1959 and a tuffaceous sandstone and conglomeratic wild claim staking rush reminiscent of the old lenses in The Dell, just east of Spor west ensued (Park, 2006). The various Be Mountain. The area has been extensively properties in the district were eventually faulted, but largely by small-displacement consolidated by Brush Beryllium Company normal faults. (now Materion Natural Resources). The Be deposits are mostly located Beryllium mining began in 1968 with Be southwest of the Spor Mountain Paleozoic production initiated the following year after block and are localized by northeast-trending, completion of the mill near Lynndal. down to the southeast, normal faults/feeders. Recently, International Beryllium All of the important Be deposits in the district Corporation (IBC) acquired a large block of are associated with the 21 Ma topaz rhyolites ground (about 7630 acres) in the pediment of the Spor Mountain Formation. The primarily to the south of the Materion Natural rhyolite has sanidine, , Resources property. IBC completed an plagioclase, and biotite phenocrysts with airborne magnetic and radiometric survey of accessory Fe-Ti oxides, fluorite, topaz, their claims during the summer of 2010 and zircon, and allanite (Christiansen and others, used it to define exploration/drill targets. 1986). The host is the Miocene “beryllium The Spor Mountain district is the central tuff member” of the Spor Mountain point on a 60-mile-long, east-northeast- Formation which contains abundant trending belt of Miocene to Pliocene (22 to 4 carbonate fragments near the base. The host Ma) felsic volcanism in Juab and southern tuff is thickened, up to 300 ft, in northeast- Tooele Counties referred to as the Beryllium trending half-grabens. The Spor Mountain Belt (Cohenour, 1963a). Spor Mountain Formation is in turn overlain by the post- consists of a southwest-tilted block of mineral 6 Ma Topaz Mountain Rhyolite Ordovician to Devonian carbonate rocks with (Davis, 1984; Christiansen and others, 1986; lesser interbedded shales and orthoquartzites. Lindsey, 2001). The eastern boundary of Spor Mountain is a Beryllium mineralization occurs as normal fault marking the western edge of the epithermal, stratiform, disseminated, large Oligocene Thomas Caldera. These replacement deposits that are typically sedimentary strata are unconformably tabular, 5 to 60 ft thick, 500 to 1000 ft wide, overlain by Eocene to Miocene volcanic and and 1500 to 10,000 ft long. The Be deposits volcaniclastic rocks. The district’s fluorite are believed to be the result of ascending, F- was derived from a series of breccia pipe and and Be-rich hydrothermal fluids. The fluids smaller vein deposits cutting up through the were driven up northeast-trending faults to Paleozoic rocks. The fluorite pipes are the beryllium tuff member where it spread

28 out laterally in a zone of increased porosity Based on the distribution of Spor Mountain and permeability. The high fluorine activity flow domes, the distribution of the Spor of the fluid replaced the carbonate clasts, Mountain Formation, and the intensity of producing fluorite nodules, the fluid then lost mineralization, he suggested a location for its -complexing Be-carrying capacity, this hypothetical pluton beneath Spor and precipitated bertrandite [Be4(Si2O7)(OH) Mountain, approximately a half mile west of 2], although beryllium-bearing smectite clays Eagle Rock Ridge. Alternately, the (saponite) can also occur in the deposits (Foley mineralizing plug could be located and others, 2010). The Be mineralization is underneath a 1.5 mi diameter, circular normal generally associated with fluorite, manganese fault system near the Claybank Be prospect, oxides, and opaline silica in an argillic or Fluorine Queen F breccia pipes, a series of feldspathic (adularia?) altered tuff, but the rhyolitic vents under Eagle Rock Ridge and fine-grained bertrandite, which is clear and just west of the Yellow Chief U mine. colorless, cannot typically be visually Bullock (1981) reports the only copper recognized in hand sample (figure 5). The mineral in the Spor Mountain district occurs bertrandite occurs as inclusions in fluorite at the Eagle Rock Be prospect on the (Foley and others, 2010). The Be zone occurs northeast slope of Eagle Rock Ridge. A plus near the top of the tuff under a relatively 100 nanoTeslas aeromagnetic high is located impermeable porphyritic rhyolite capping and under The Dell in this area (section 23-26, T. is in turn underlain by a thick zone of Li-rich 12 S., R. 12 W., SLBM) (Kucks, 1991). smectite clay (hectorite?) and low-grade U Geochemical analysis of ore from the Be and Th, about 850 ppm and 100 ppm, deposits southwest of Spor Mountain (46 respectively (Christiansen and others, 1986). NGDB samples averaging 0.63% Be) shows The Be deposits and fluorite pipes are anomalous As, F, Ge, Li, Mn, Nb, Pb, Sn, Tl, believed to have formed from ascending, W, Zn, and anomalous REE Ce, Dy, Er, Gd, hydrothermal fluids derived from a cooling Ho, Nd, Sm, Y, and Yb (table 6). These high-silica granitic pluton at depth, possibly samples are HREE-enriched, have an similar to the nearby and similarly aged estimated TREO value of $24 per ton (table Sheeprock Granite (20.9 Ma). Lindsey 6), and could constitute a byproduct credit to (1982) postulated that uraninite or coffinite the Be operation if recovered. SITLA veins, similar to those near Marysvale, could controls the mineral rights under private be present in this hypothetical granite pluton. surface ownership to a large block of ground

Figure 5. Fluorite-chalcedony-bertrandite Be ore nodule from an open pit at Mate- rion's (Brush Wellman) Spor Mountain op- eration, Juab County (3 inch pocket knife for scale).

29 (about 8250 acres) on the main Be producing was anomalous in Eu and Y by semi- area southwest of Spor Mountain (figure 6). quantitative XRF. SITLA has the surface and In addition, one NURE soil sample (table mineral rights to partial section 2, T. 13 S., R. 6) with “mining contamination” from east of 12 W., SLBM (607 acres) and the E½, E½, the south end of Eagle Rock Ridge (E½, section 36, T. 12 S., R. 12 W., SLBM (160 SE¼, SE¼, section 36, T. 12 S., R. 12 W., acres), immediately south and east, SLBM) was very strongly anomalous in La respectively, of the NURE sample, which is (22,947 ppm or about 2.7% REO) and on BLM ground (figure 7). anomalous in Sm (132 ppm). This NURE sample could be considered “ore Sheeprock Granite, Tooele County grade” ($138 per short ton TREO) in REE. Preliminary XRF and XRD work on one The southern Sheeprock Mountains of fluorite nodule from the nearby Hogsback Be southeastern Tooele County are covered by mine collected by Jim Davis and analyzed by the Columbia (northeast) and East Erickson Taylor Boden and Ammon McDonald of the (southwest) mining districts (figure 3, site UGS, suggests a REE-bearing fluorite – 74). The Sheeprock Mountains are on the tveitite may be present. This later sample eastern end for a 60-mi-long, east-northeast-

Figure 6. Topographic map of beryllium open pit mines (red polygons) in the pediment southwest of Spor Mountain; SITLA mineral rights are designated by blue outlines. Note section lines for scale.

30 Figure 7. Topographic map of the Eagle Rock Ridge area, southeast of Spor Mountain, Juab County. Small red polygon in the south-center of section 35 is the Hogsback open pit Be mine, yellow polygon in northwestern section 36 is the Yellow Chief open pit U mine, and the strongly anomalous NURE soil sample (black hexagon) is in the southeast corner of section 35. The blue outlines define the SITLA mineral rights; note section lines for scale. trending belt of Miocene to Pliocene (22 to 4 Small sediment-hosted Au occurrences lie 7.5 Ma) felsic volcanism in Juab and southern mi to the east in the Blue Bell district and 6 Tooele Counties referred to as the Beryllium mi to the north near Lookout Pass. Belt (Cohenour, 1963a). The Columbia and Beryl was initially recognized in the East Erickson mining districts produced a granite by Richard Ekker in the early 1940s. small tonnage of Pb-Ag, Mn, and Fe ores In 1953, his property in Hard to Beat Canyon beginning in about 1908, primarily from the was mapped, sampled, and drilled by Brush Sharp Pb-Ag mine about a mile east of the Beryllium Company, but was determined to granite. A low-grade W prospect (scheelite) be very low grade, averaging only about 40 was explored on Greens Ridge southeast of ppm Be; however, some grab samples ran as the main granite exposure, in the mid-1950s. high as 27,720 ppm Be. The Be area was

31 later explored by Ran Rex Mining Company disseminated grains, (2) rosettes of radiating (a promotional outfit) which did sporadic crystals as much as 2 ft in diameter, (3) in work over a few years, including driving tiny, but massive seams/veins, and (4) in several hundred ft of underground drifts small aplite dikes and quartz veins (Williams, (Cohenour, 1963b). Anaconda 1954). Minor danalite [Fe4Be3(SiO4)3S] is unsuccessfully examined the granite and also reported (Thomssen, 1959, unpublished surrounding area (controlling over 550 note in UGS files). claims) in the late 1970s for U. This work Narrow, northeasterly trending greisen included a reconnaissance, nine-hole, 2400-ft veins (quartz, muscovite, fluorite, hematite, drilling program. magnetite, galena, sphalerite, and rare topaz) The Sheeprock Mountains are composed host weak Sn-W-HREE (cassiterite- of a thick sequence of northeast-dipping wolframite-huebnerite) mineralization cutting Proterozoic Sheeprock Group quartzite, the granite (Christiansen and others, 1991). metaconglomerate, and slate on the northeast The sides of the granite (northwest and flank of the range intruded by the Miocene southeast contacts) have been prospected for (20.9 Ma) Sheeprock Granite on the Cu-F-U ±W mineralization, and the area southwest flank. The intrusion is an “above” (northeast of) the granite has aluminous, anorogenic (A-type), high-silica primarily produced minor Pb-Zn-Ag-Mn granite (Christiansen and others, 1988). The (specularite) mineralization. Seven NGDB range has been rotated eastward by post- samples near the Sheeprock Granite assay intrusive listric extensional faulting so that a over 100 ppm Sn. deeper level of the early Miocene Sheeprock The zircon, apatite, monazite, thorite, system is exposed on the west and higher uraninite, and samarskite accessory minerals levels are exposed on the east. In general, the in the granite are known to be, or could “upper” (northeast) half of the granite is fine- potentially be, REE-bearing. In addition, grained and porphyritic and the Cohenour reports two small samarskite- “lower” (southwest) half is medium grained bearing pegmatites and Nielson (1977, and porphyritic (Richardson, 2004). unpublished Anaconda Company data in The 7.8-sq-mi, red, oxidized Sheeprock UGS files) reports Th to 2437 ppm and U to Granite has a 1.4-sq-mi highly differentiated 539 ppm in one biotitic pegmatite. However, “white facies” core containing smoky quartz while portions of the granite are slightly (25%), perthite (35%), albite (30%), elevated in HREE, it is not reportedly orthoclase (5%), biotite (5%), and blue beryl significantly enriched in the analytical work (Cohenour, 1959; Christiansen and others, currently available. 1991; Richardson, 2004). The “white facies” The land in the area of the differentiated varies from medium grained and slightly core is dominantly BLM-administered with porphyritic to nearly pegmatitic with lesser fee ground. Scattered SITLA tracts lie phenocrysts of quartz and orthoclase. The to the south of the Sheeprock Granite. granite has ilmenite, magnetite, muscovite, zircon, apatite, monazite, thorite, uraninite, Blawn Mountain, Beaver County fluorite, samarskite, and topaz as accessory minerals. There are also some small The Blawn Mountain mining district is pegmatites and aplite dikes. The “white located in southwestern Beaver County, facies” is known to be enriched in Be, Th, approximately 7 mi southeast of Pine Grove and HREE (Christiansen and others, 1988; (figure 3, site 75). The first mention of Richardson, 2004). Beryl occurs as (1) mining in the Blawn Mountain area is a very

32 brief note about Fe mining on the east flank communication, July, 2007) notes the of the range in the 1880s (Butler and others, occurrence of good crystalline cassiterite 1920). The Staats fluorite mine, on the south [SnO2] in a fluorspar breccia near the Staats flank of Blawn Mountain, was first staked in mine. A NGDB sample from the Staats mine 1931 and subsequently purchased by Fred shows strongly anomalous Y (table 6). The Staats and associates in 1938. The fluorite REE may be associated with the phosphates - property was worked by a small open cut and autunite and uranophane. has an estimated 800 ft of underground The Staats mine lies on a SITLA section workings. Some 4855 short tons of fluorite (E½, SE¼, NE¼, section 36, T. 29 S., R. 16 were mined from 1935 to 1951. During the W., SLBM), largely surrounded by BLM- 1950s, U was discovered at the Staats mine administer lands. The large SITLA Blawn and an additional 1994 short tons of 0.258% Wash block lies a mile to the east. U3O8 ore were shipped. The area was heavily explored for U again in the mid- Newton District, Beaver County 1970s, and then for Mo in the late 1970s and early 1980s, following the discovery of the Newton is a small mining district located deep, Climax-type porphyry Mo deposit to northeast of Beaver on the west flank of the the north at Pine Grove. Tushar Mountains (figure 3, site 76). It The mineralization at the Staats mine is covers part of the Marysvale volcanic field. associated with one of several small, silicic- The host rocks are predominantly Oligocene alkalic, porphyry plugs known to be Bullion Canyon calc-alkaline andesitic associated with the Miocene Blawn volcanic rocks intruded by Miocene quartz Formation volcanic rocks. These plugs latite and rhyolite porphyries. Mineralization include the Pine Grove porphyry, Staats in the district is predominantly small, rhyolite, and the Blawn Wash plugs. Keith auriferous, low-sulfidation, epithermal, and others (1986) report a 23-22 Ma date for quartz-carbonate veins and U-Mo-W the Pine Grove porphyry. The small topaz prospects. rhyolite plug adjacent to the fluorite-U The U-Mo-W mineralization is associated mineralization at the Staats mine intrudes a with Miocene (about 18 Ma) Mount Belknap sequence of Silurian and Devonian rhyolite porphyries and breccia pipes in the carbonates and was dated at 20.2 Ma upper reaches of North Creek, immediately (Mehnert and others, 1978). west of Mount Baldy, that is, The fluorite ore zones, grading Hollow (Cunningham and others, 1984). approximately 75 to 90% CaF2, are typically This location shows a dramatic, progressive, a few ft in width, a few tens to just over 100 multi-element, headward NURE stream ft in length, and occur near the rhyolite sediment sample geochemical increase over a contact. The autunite and uranophane [Ca distance of about 5 mi. REE showing (UO2)2SiO3(OH)2·5(H2O)] after uraninite increases include Ce, La, Y, and other [UO2] occur as small flakes and coatings in elements display similar increases include gouge zones adjacent to the fluorite with Mo, Be, Zn, and Mn. An average of two typical grades of less than 0.2% U3O8 NURE stream sediment samples from about (Whelan, 1965; Bullock, 1976). Lindsey and 8000 ft west of Mount Baldy are anomalous Osmonson (1978) note the occurrence of very in Ce, La, and Y (table 6). Interestingly, low-level geochemical anomalies for Sn, Mo, huebnerite [MnWO4], which occurs above and Be associated with the rhyolite stock. the Pine Grove porphyry Mo deposit, is Lindsey (retired USGS, written reported from quartz veins in the Pole

33 Canyon branch of North Creek (Everett, generally prograde and dry, containing few 1961). hydrous minerals. The Fishlake National Forest completely Very low-grade mineralized skarns may covers the North Creek area. The Tungsten be up to 30 ft wide, 100 ft deep, and 800 ft Hollow system, near the crest of the range, is long, although the ore mined to date occurs in being studied by the USFS as part of a much smaller (up to a few hundred short proposed roadless/wilderness area. tons), higher-grade (0.7% WO3), structurally controlled pods unevenly distributed within Granite District, Beaver County these broader low-grade zones (Everett, 1961). The primary ore mineral is scheelite The Granite mining district covers a typically found with pyrite and fluorite. narrow, 8-mi-long strip along the east flank Scheelite, beryl, and helvite [Mn4Be3(SiO4) of the Mineral Mountains in east-central 3S] occur in some of the pegmatites. Beaver County (figure 3, site 77). The Powellite [CaMoO4] is present locally in the district has produced several hundred short skarns (Hobbs, 1945). The district shows a tons of W ore and a similar tonnage of Zn- broad but weak zonation from Pb-Zn-rich Pb-Cu ±Bi ores. The Mineral Mountains ores on the north and south to higher W, Sn, expose a large, mostly gray, alkalic, high- and Mo in the center, near the Garnet and silica, composite Oligocene-Miocene (25 to Contact mines. NGDB samples from the 18 Ma) granite, monzonite, and syenite Granite district also run up to 450 ppm Sn batholith (80 sq mi), the largest exposed and 70 ppm Mo. A NURE stream sediment batholith in Utah. The main granitic phase sample in Porcupine Canyon, near the Miller of the Mineral Mountains batholith has been mine contained anomalous REE (table 6). interpreted (Coleman and others, 2001) to The majority of the land in the Granite have an age of about 18 to 17 Ma. The district is managed by the BLM with limited batholith has been strongly rotated to the east private ownership. A section of SITLA land (40º - 85º), so that the east side of the occurs just northeast the prospective skarn mountain is near the paleo-top of the zone in section 16, T. 28 S., R. 8 W., SLBM. batholith. This rotation is evident from the subvertical dip of the Bullion Canyon Pliocene Intrusive Systems Volcanics (29 - 22 Ma) on the east flank of the range (Coleman and others, 2001). Honeycomb Hills, Juab County Mineralization is developed in garnet- vesuvianite- skarns formed near the The Honeycomb Hills are part of a low eastern (upper) contact of the quartz range of hills in the northern Snake Valley monzonite and the Mississippian Deseret between the southern Deep Creek Range to Limestone (?). The quartz monzonite the west and the Fish Springs Range to the porphyry is finer grained at the contact and east (figure 3, site 81). The Hills lie along there are minor pegmatitic phases and quartz the Callao to Sand Pass road, about 15 mi veins associated with the border facies. The southeast of Callao. The area has no reported carbonates generally strike to the north- production, but has seen a series of mineral northeast and dip very steeply. The exploration programs over the last half carbonates are skarnified for a distance of a century. Volcanic-hosted U mineralization few hundred ft from the batholith and was discovered in the Honeycomb Hills by marbleized or bleached for about 1000 ft H.P. Bertelsen in 1950, but grades were (Sibbett and Nielson, 1980). The skarns are typically below 0.1% U3O8. In 1961, C.R.

34 Sewell discovered Be mineralization there flow domes that erupted about 4.7 Ma (Byrd while working for The Dow Chemical Co. and Nash, 1993). The rhyolite is gray, Dow cut some dozer trenches and drilled a vesicular, and strongly flow-banded; it series of 15 exploration holes totaling 2930 contains about 40% phenocrysts of smoky ft. Reported assays ran from 0.05% to 0.85% quartz with sanidine, plagioclase, and biotite. Be (Montoya and others, 1964); however, Topaz crystals commonly line the vesicles. most samples assayed below 0.73% Be The rhyolite also contains globular topaz- and (McAnulty and Levinson, 1964). Anaconda fluorite-bearing inclusions (Christiansen and held a property position in the district from others, 1986). Paleozoic carbonates 1977 to 1979 while exploring for U. Redhill (Devonian?) lie beneath the domes at depth Resources Corp. acquired 64 unpatented lode of about 200 ft (McAnulty and Levinson, claims covering the Honeycomb Hills as a 1964). REE project in 2010. Redhill is a The Honeycomb Hills REE property Vancouver-based, Canadian junior hosts a variety of unusual minerals including: exploration company primarily interested in fluorite, autunite, boltwoodite [HK(UO2) gold and REE. Redhill reports surface (SiO4)1.5(H2O)], ralstonite [Na0.5Mg0.5Al1.5F4 samples running up to 4300 ppm Be, 1690 (OH)2(H2O)], saléeite [Mg(UO2)2(PO4)210 ppm Li, 1270 ppm Rb, and 1043 ppm TREO. (H2O)], sklodowskite [(H3O)2Mg(UO2)2 The Honeycomb Hills are the (SiO4)24(H2O)], soddyite [(UO2)2(SiO4)2 westernmost point on a 60-mi-long, east- (H2O)], thomsenolite [NaCaAlF6(H2O)], northeast-trending belt of Miocene to tridymite, uranophane, and possibly Pliocene (22 to 4 Ma) felsic volcanism in bertrandite. Low-grade Be, Li, Cs, and Rb Juab and southern Tooele Counties referred occur in an approximately 3-ft-thick zone in to as the Beryllium Belt (Cohenour, 1963a). the uppermost tuff, immediately underlying The Honeycomb Hills volcanic complex the capping massive Bell Hill (northwestern) consists of a 40-ft-thick, Pliocene, lithic, rhyolite dome (figure 8) (McAnulty and fluorite-bearing, air-fall (?) tuff, immediately Levinson, 1964). Some samples also contain underlain by older volcanic rocks, and anomalous Mo and Sn (Christiansen and overlain by two small coeval topaz rhyolite others, 1986). The Honeycomb Hills REE

Figure 8. Bell Hill at the Honeycomb Hills, Juab County, looking west. Note the strong flow-banding in the Pliocene, topaz rhyolite flow dome (photograph courtesy of Jim Davis, UGS).

35 geochemistry (table 6) is anomalous in Dy, a normal fault on the west side of the main Lu, Tb, Tm, Y, and Yb and is strongly hill. enriched in HREE. Four full SITLA sections (surface and Unusual REE Occurrences minerals) surround the Honeycomb Hills prospect: section 32, T. 12 S., R. 15 W., Cane Creek Potash Mine, Grand County SLBM; section 36, T. 12 S., R. 16 W., SLBM; section 16, T. 13 S., R. 15 W., An unusual occurrence of the REE- SLBM; and section 2, T. 13 S., R. 16 W., bearing mineral, braitschite, is reported in the SLBM; however, none of these sections Paradox Basin from the Cane Creek potash contain known REE prospects. mine, 7 mi southwest of Moab in Grand County (figure 3, site 91). The braitschite Smelter Knolls, Millard County occurs in white to reddish-pink nodules in an anhydrite bed immediately overlying potash Smelter Knolls is located in north-central zone 5 throughout the mine and in a core hole Millard County about 16 mi west-northwest about a mile to the south (Raup and others, of Delta (figure 3, site 82). Smelter Knolls 1968). The anhydrite and potash beds are consist of a group of rhyolite hills covering part of a 14,000-ft-thick sequence of marine an area of about 6.5 sq mi and rising 400 ft evaporates in the Pennsylvanian Paradox above the surrounding Sevier Desert floor. Formation. Little other information is The Knolls consist of a series of Pliocene available on the REE-bearing anhydrite bed. (3.4 Ma) coalescing topaz rhyolite flows and Interestingly, a NURE stream sediment domes. Turley and Nash (1980) estimate the sample taken about a mile downstream from complex contains about 0.54 mi3 of rhyolite. the Cane Creek evaporation ponds shows The Rhyolite of Smelter Knolls is white anomalous Ce, La, Sm, Dy, Lu, Tb, and Yb. to light reddish gray, flow-banded rhyolite There is a large block (about 13,545 acres) of porphyry. The principal minerals are quartz, SITLA mineral rights covering the Cane alkali feldspar (sanidine), plagioclase, biotite, Creek potash operation in T. 26 and 27 S., R. and lesser topaz, fluorite, zircon, and 20 and 21 E. It should be worthwhile to titanomagnetite with topaz and hematite in determine the REE content of the various lithophysal cavities. Limited geochemistry evaporation ponds. (table 6) suggests that the Rhyolite of Smelter Knolls is anomalous in Dy (26 ppm), Lu (3 South Ouray Oil Shale, Uintah County ppm), Sm (14 ppm), Tb (3 ppm), Y (185 ppm), and Yb (22 ppm) (Turley and Nash, The REE-bearing mineral, burbankite, 1980; Nash, 1991). Like most of the topaz and a large suite of other unusual minerals rhyolite related systems, Smelter Knolls has a are reported from oil shale of the Eocene low LREE/HREE ratio, i.e., it is relatively Green River Formation in the Uinta Basin of enriched in HREE. Uintah County (figure 3, site 92). REE- SITLA controls the surface and mineral bearing minerals are also known from the rights to two sections in the Smelter Knolls Green River Formation in Wyoming (King area: sections 2 and 16, T. 16 S., R. 9 W., and Hausel, 1991). Burbankite has been SLBM. Section 2 (790 acres) lies to the reported from 1700 to 2300 ft deep in a northeast of the main rhyolite hill at Smelter number of wells south of Ouray, Utah (figure Knolls and section 16 (644 acres) lies astride 3). The other minerals reported from these holes include an unusual suite of Na- and Ba-

36 bearing minerals including neighborite Paleoproterozoic pegmatites to Pliocene [NaMgF3 ], leucosphenite high-silica rhyolites. The potential sources of [Na4BaTi2B2Si10O30], nahcolite [Na(HCO3)], REE in Utah were evaluated based on (1) a barytocalcite [BaCa(CO3)2], garrelsite favorable deposit type, (2) recognized REE [Ba3 NaSi2 B 7 O 16(OH)4 ], wurtzite minerals, and/or (3) geochemical data. [Zn0.9Fe0.1S], and shortite [Na2Ca2(CO3)3] Unfortunately, the geochemical data (Chao and others, 1961). No geochemical compiled for this report were not collected data are available for the drill holes in the for REE, analyzed for all of the REE, nor Ouray area; however, some NURE stream selected in hopes of collecting REE-enriched sediment samples in the region are material. These data should be viewed only anomalous in the REE Ce and Sm in addition as a semi-quantitative tabulation of areas that to Ba and Sr. The South Ouray burbankite may have REE potential. occurrences do not present readily apparent The most favorable geological REE targets despite the presence of large environments in Utah for REE appear to be amounts of SITLA land in the area. late Paleozoic phosphorite and late Tertiary intrusive-related deposits (table 7). The most SUMMARY prospective intrusive related deposits cluster in the Miocene (24 to 18 Ma) and are The REE are a group of 16 geochemically associated with high-silica rhyolites and similar lithophile elements comprising the 15 , primarily in west-central Utah. lanthanides and yttrium. In igneous rocks, The best potential sources for REE the REE act as incompatible elements and are production in Utah are byproducts of concentrated by magmatic differentiation into phosphate operations (Simplot Phosphates), the last crystallizing stages of felsic igneous Be mines (Materion Natural Resources), or rocks, carbonatites, alkaline intrusive rocks, possibly the Cane Creek potash mine aplites, and pegmatites. In sedimentary (Intrepid Potash – Moab). The most rocks, the REE most commonly occur in favorable area for REE on SITLA lands is in phosphorites and placer deposits. the Spor Mountain mining district of Juab The world’s total primary REE market is County. Geochemical analysis of ore from estimated to be about a $2-3 billion industry the Spor Mountain Be deposits (46 samples and is dominated by China (91%). Recently, averaging 0.63% Be) shows anomalous REE. China began to increase its export taxes and These samples are HREE-enriched, have an severely limited the export of REE raw estimated TREO value of $24 per ton, and materials, prompting strong increases in REE could constitute a byproduct credit to the Be prices and a resurgence of REE exploration operation if it were found that they could be and development in the west. The current economically recovered. SITLA controls the major producer (Bayan Obo, China) and the mineral rights (about 8250 acres) under two most advanced development projects private surface ownership to a large block of (Mountain Pass, USA, and Mount Weld, ground on the main Be-producing area Australia) are all light REE-enriched southwest of Spor Mountain. deposits, suggesting potential future markets In addition, one isolated NURE soil for the more valuable heavy REE. sample from southeast of Spor Mountain was Utah has no recorded REE production very strongly anomalous in La (22,947 ppm) and has no known carbonatites; however, and Sm (132 ppm). This sample could be REE occur in a wide variety of geological considered “ore grade” ($138 per ton TREO) environments in Utah ranging from in REE. SITLA has the surface and mineral

37 1 1 1 3 1 1 1 3 2 5 4 4 4 4 5 2 2 3 1 5 2 SITLA Lands

Dy, Lu, Sm, Tb, Y, Yb Lu, Sm, Dy, Eu, Lu, Yb Ce, Nd, Pr, Sm Ce, La, Y Y Ce, Eu, Gd, La, Nd 2 Ce Ce, Dy, La, Lu, Sm, Tb, Tb, La, Lu, Sm, Ce, Dy, Yb Ce, Lu, Sm, Tb, Y, Yb Ce, Lu, Sm, 2 Ce, Eu, La, Nd, Pr, Sc, Y Ce, Eu, La, Nd, Pr, Sc, Ce, Dy, Er, Gd, Ho, La, Ce, Dy, Nd, Sm, Y, Yb Tb, Y, Yb Ce, Lu, Sm, 2 La 2 Ce, Eu, La, Pr, Tb Ce, Eu, La, Pr, 1 Ce, La Dy, Er, Gd, Ho, La, Nd, Dy, Y, Yb Er, Eu, Gd, Ho, Ce, Dy, Yb La, Nd, Sm, Y, Ce,Dy, Eu, Lu, Sm, Y, Eu, Lu, Sm, Y, Ce,Dy, Yb Ce t. Samarskite and fergusonite Monazite, titanite, al- lanite Samarskite, xenotime, monazite Allanite, titanite, apatite Perovskite, armalcolite, hibonite 90 Monazite and allanite? La, Y 22 Apatite 18 Titanite and apatite Ce, La, Lu, Sm, Y, Yb 2 ozoic 1,800 Cyrtolite ous 90 Monazite and allanite? Age Ma REE Minerals Geochemical Anomalies ne 22 Brockite ne 48 Burbankite aceous 90 Monazite and allanite liocene 3 Unknown Eocene 39 Miocene 21 ite? Paleoproterozoic 1,800 Unknown Ce, La, Y 1 e Miocene 20 Unknown atite Paleoproterozoic 1,800 Unknown Type Type ite Oligocene 30 Unknown aporite Pennsylvanian 307 Braitschite Alkaline Jurassic 152 Pegmatite Jurassic 149 Samarskite and apatite Ce, Eu, Nd Placer Cretaceous 90 Monazite and allanite Y Placer Eocene 39 Monazite and allanite? Topaz Rhyolite Pliocene 5 Placer Cretaceous Th Vein Mioce Pegmatite, Placer Peralkaline Granite Topaz Rhyolite Miocene 21 Allanite P egmatite Paleoproterozoic 1,700 Unknown Placer Cretace Phosphate Permian 272 Apatite and loparite? Oil Shale Eoce Peralkaline Oligocene 24 Fluor Topaz Rhyolite P Fluorit Placer Cret Iron Ore Miocene Peralkaline Miocene eber Pegmatite Paleoproter County Juab Garfield Tooele Piute Daggett, Morgan, Rich, Uintah, Utah, Wasatch Uintah Rich, Box Elder Phosphate Mississippian 345 Apatite and loparite? Batholith Juab Batholith Lion Black Sands Box Elder Honeycomb Hills Hills Honeycomb Shoshonite Indian Springs Bench Yellow HammerTooele Pipe Granite Mountain Pegmatite Black Canyon Pine Skarn Monroe Canyon Sevier Various Laketown in in Ouray District/Area Property Table 7. Utah REE Prospects. Uinta Bas Honeycomb Hills Hills Honeycomb Smelter Knolls Paradox Basin Smelter Knolls Cane Creek Millard Grand, San Juan Ev Straight Cliffs MountainFiftymile Mann-Longshot Henry Mountains Calf Canyon Kane Coal Cliffs Garfield Ferron Sandstone Emery Ibapah Ibapah Lucin Washington District Cougar Spar mine Beaver Mineral Mountain Granite District Beaver Erickson District Newton District Sheeprock Batholith Tooele MountainBlawn North Creek Staats mine Beaver, Piute Beaver Alkaline Miocene 21 Unknown Granite Peak Sevier Plateau Iron Springs Monroe Spor Mountain Iron Mountain Brush Beryllium Iron Juab Meade Peak Phos- phatic Shale Gold Hill 1. SITLA lands, 1 no coverage, 2 in the general to occurrence, area, 3 proximal 4 partly covering target, and 5 covering targe Farmington Complex Weber Canyon Farmington Complex Devils Hollow Davis, Morgan, W Morgan Pegm Farmington Complex Morgan area Box Elder, Weber Pegmat Beaver Dam Gneiss Welcome Spring Washington Delle Phosphatic Shale

38 rights to partial section 2, T. 13 S., R. 12 W., Agrell, S.O., Chinner, G.A., and Rowley, SLBM (607 acres) and the E½, E½, section P.D., 1999, The black skarns of Pine 36, T. 12 S., R. 12 W., SLBM (160 acres), Canyon, Piute County, Utah: Geological immediately south and east, respectively, of Magazine, v. 136, p. 343 - 359. this anomalous REE sample site, which is on BLM ground. Andreasen, K.C., 2007, Does the southern Braitschite, a REE-bearing mineral phase Farmington Canyon Complex record a is reported from the Cane Creek potash mine Late Archean/Early Proterozoic and a NURE stream sediment sample taken accretionary complex?: Logan, Utah, below their evaporation ponds is anomalous Utah State University M.S. thesis, 135 p. in REE. There is a large block (about 13,545 acres) of SITLA mineral rights covering the Barker, D.S., 1995, Crystallization and Cane Creek potash operation in T. 26 and 27 alteration of quartz monzonite, Iron S., R. 20 and 21 E. and there may be some Springs mining district, Utah - relation to potential for a REE byproduct. associated iron deposits: Economic Geology, v. 90, p. 2197-2217. ACKNOWLEDGEMENTS Best, M.G., Grant, S.K., Hintze, L.F., Cleary, This report was prepared at the request of J.G., Hutsinpiller, A., and Saunders, Thomas B. Faddies, SITLA assistant director D.M., 1987, Geologic map of the Milford of minerals, and supported by SITLA quadrangle and east half of the Indian financial assistance in fiscal year 2010-2011. Peak (Southern Needle) Range, Beaver This report would not have been possible and Iron Counties, Utah: U.S. Geological without the cooperation of the Utah Survey Miscellaneous Investigations I- Geological Survey. The figures were 1795, scale 1:50,000. generated by Jay Hill and Stevie Emerson. The author benefited from REE discussions Bick, K.F., 1966, Geology of the Deep Creek with Jon King and GIS assistance from Jay Mountains, Tooele and Juab Counties, Hill. The text was greatly improved by Utah: Utah Geological and Mineralogical thorough editorial reviews from Dave Tabet Survey Bulletin 77, 120 p. and Robert Ressetar. Cheryl Gustin did a beautiful job of compiling the text, tables, Biek, R.F., Rowley, P.D., Hayden, J.M., and figures into a completed document. Hacker, D.B., Willis, G.C., Hintze, L.F., Anderson, R.E., and Brown, K.D., REFERENCES 2009, Geologic map of the St. George and east part of the Clover Mountains 30’ Adams, J.W., 1965, Rare earths, in Mineral x 60’ quadrangles, Washington and Iron and water resources of New Mexico: Counties, Utah: Utah Geological Survey New Mexico Bureau of Mines and Map 242, 101 p., scale 1:100,000. Mineral Resources Bulletin 8, p. 234-237. Bryant, B., 1988, Geology of the Farmington Adams, J.W., 1969, Thorium and rare earths, Canyon Complex, Wasatch Mountains, in Mineral and water resources of Utah: Utah: U.S. Geological Survey Utah Geological and Mineralogical Professional Paper 1476, 54 p. Survey Bulletin 73, p. 115-119.

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46 Appendix. Periodic table of the elements with the REE highlighted.

47