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GRC Transactions, Vol. 33, 2009

Geothermal Discovery Near Corner Canyon, Salt Lake County,

Robert E. Blackett1, J. Lucy Jordan2, Kevin Thomas2, Janae Wallace2, and Robert F. Biek2 1Utah Geological Survey, Cedar City, Utah 2Utah Geological Survey, , Utah

Keywords of the , up to the east and northeast. The Traverse Resource Assessment, Utah, Salt Lake County, Corner Canyon Mountains mark the boundary between the Salt Lake City and Provo segments of the . These segments are linked by the Fort Canyon fault, which trends east-west through Corner ABSTRACT Canyon and which has a long history as the northern ramp of the Sevier-age Charleston thrust fault and the middle Tertiary Deer In winter 2008, a water-supply company drilled a pilot test Creek detachment fault. well at Corner Canyon near the southern edge of Salt Lake County, southeast of Draper, Utah. The site is located at the western base Introduction of the north-south oriented Wasatch Range (Wasatch Front) near the intersection with the northeast-southwest oriented Traverse In December 2007, WaterPro, Inc. contracted to drill and com- Mountains. The well was drilled to 1270 feet (387 m). Static plete a water supply well for the growing community of Draper, water level rose to 85.6 feet (26.1 m) below ground level following Utah, located in the southeastern part of Salt Lake County. Mike completion. Air-lifting produced water at temperatures between Zimmerman Well Service began drilling on December 29, 2007. 175° and 185°F (79°-85°C). Temperature measurements during During the early stages of drilling the temperature of the return well logging three months after well completion revealed a maxi- fluid became elevated suggesting a geothermal source at depth. mum temperature of 202°F (94.4°C) from 472 to 499 feet (144 Zimmerman completed the drilling phase of the well in early -152 m), which likely coincides with the zone of most geothermal March 2008, installing a 10-inch- (25-cm-) diameter well to a fluid movement into the well. The bottom-hole temperature was total depth of 1270 feet (387 m). 195°F (90.6°C). Lithologic and geophysical logging show that the well penetrated monzogranite of the 30.5-million-year-old Location and Access Little Cottonwood Stock at 60 feet (18 m) and multiple fracture zones and possible faults are present in the upper 500 feet (152 The City of Draper is situated about 15 miles (24 km) southeast m) of the well. Analyses of fluid samples collected during a of Salt Lake City. The well is located in the SW¼, SE¼, NE¼ sec- 24-hour pump test yielded 300 gallons per minute (1136 L/min) tion 4, T. 4 S., R. 1 E., Salt Lake Base Line and Meridian (SLBM) of water with total dissolved solids content of 7360 mg/kg. The at a latitude of 40°30′4″ N. and longitude of 111°50′18″W. The water is sodium-chloride type and more similar to Ogden Hot approximate land surface elevation at the well head is 4890 feet Spring in Weber County than to other geothermal systems closer +/- 20 feet (1490 m +/- 6 m). The site is in the lower part of Corner to Corner Canyon. Silica concentration (SiO2 = 179 mg/kg) was Canyon near the southern boundary of Salt Lake County. Corner exceptionally high compared to other Wasatch Front geothermal Canyon sits at the southeast edge of the where systems. The chalcedony and K-Mg chemical geothermometers the base of the Wasatch Range intersects the Traverse Mountains suggest equilibrium reservoir temperature ranging between 302° (Figure 1). The Salt Lake County/Utah County line lies about and 358°F (150°-181°C). one mile (1.6 km) to the southeast from the well. Corner Canyon The well was sited along the surface trace of the Wasatch trends southeastward along the juncture of the two mountain fault, near the southern end of the fault’s Salt Lake City segment. ranges eventually turning due east. The site lies at the edge of Near this segment boundary, the Wasatch fault juxtaposes Eocene- the urban areas of Draper and is accessed by traveling on paved Oligocene volcanic rocks and Pennsylvanian sandstone of the roads through new subdivisions encroaching into the foothills of Oquirrh Group in the Traverse Mountains, down to the west and the Wasatch Range, then by dirt track for a few hundred feet into southwest, against rocks of the Tertiary Little Cottonwood Stock Corner Canyon. The well is near the bottom of the canyon.

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(Deer Creek fault) with contemporaneous volcanism and intrusions of the Wasatch igneous belt occurring from about 40 to 20 million years ago (mya), and 2) basin-and-range extension and differential uplift that produced normal faulting beginning in Miocene time and continuing to the present. This second episode, beginning about 17.5 mya (Hintze, 2005) and extend- ing to the present, produced the Basin and Range physiographic province with its numerous north- south-trending, tilted mountain ranges bounded on at least one side by high-angle normal faults. Wasatch Fault Zone The Wasatch fault zone marks the western margin of the Wasatch Range and represents the boundary between the Middle Rocky Mountains province to the east and the Basin and Range province to the west. Hecker (1993) describes Quaternary tectonics in northern Utah as concentrated within a 124-mile- (200-km-) wide zone centered on the Wasatch fault zone and coincident with the Intermountain seismic belt. The Wasatch fault zone extends 211 miles (340 km) from southern Idaho through northern, and into central Utah. It is the most tectonically active structure in this region and exhibits abundant evidence of recurrent surface rupture during the Holocene (Machette and others, 1992; Schwartz and Coppersmith, 1984). Geologists recognize several segments of the Wasatch fault. Each segment is bounded by a bed- rock projection (often called a spur) or a significant step-wise offset to the surface trace. The Salt Lake segment (Figure 1) is bounded on the north by a spur called the Salt Lake salient that projects westward from the Wasatch Front between Salt Lake City and Bountiful. On the south, the Traverse Mountains, extending west from Alpine, separate the Salt Lake Figure 1. General geology of the Valley region, northern Utah showing locations segment from the Provo segment (see, for example, and temperatures of selected geothermal wells and springs. Geology from Hintze and others (2000). Hintze, 2005). Between Alpine and Corner Canyon, the Wasatch fault offsets bedrock, down-dropping Geology, Hydrogeology, and Pennsylvanian Oquirrh Group rocks and Tertiary Geothermal Systems (late Eocene to Miocene [?]) volcanic rocks and alluvial deposits of the Traverse Mountains relative to the Tertiary Cottonwood Regional Setting Stock of the Wasatch Range. At Corner Canyon, near the southern end of the Salt Lake Davis (1983) described the geology of the central part of the City segment, the Wasatch fault makes an abrupt bend to the east- Wasatch Front as diverse with rocks representing nearly every southeast, coincident with the trace of the Sevier-age Charleston geologic period from Precambrian to Quaternary. The Wasatch thrust fault. Machette (1992) referred to this east-trending part of Range comprises the westernmost range of the Middle Rocky the Wasatch fault, which links the Salt Lake City and Provo seg- Mountains physiographic province with peaks reaching elevations ments, as the Fort Canyon fault, which dips about 25° south and in excess of 11,000 feet (3350 m). The range has about 7000 feet exhibits a significant amount of down-to-the-southwest oblique (2130 m) of relief. Rocks in the Wasatch Range have undergone slip (Evans and others, 1997; Bruhn and others, 2005). The at least two major episodes of mountain building (orogeny). Biek Charleston thrust fault is the northern boundary fault (edge) of (2005b) describes events leading to the current geologic features the Charleston-Nebo thrust sheet. During the Sevier orogeny, the seen in the study area including 1) Sevier-age compression where Charleston thrust resulted from a protracted period of compression great thicknesses of Pennsylvanian-Permian Oquirrh Group rocks between about 100 and 40 million years ago (early Late Cretaceous were folded and thrust eastward, followed by regional uplift and to late Eocene). The Charleston thrust fault separates allochtho- collapse of the orogenic belt along low-angle detachment faults nous terrain to the south (displaced roughly 50 miles [80 km] from

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the west) from autochthonous terrain to the north exposed in the near Point-of-the-Mountain on the south end of the Salt Lake Val- Wasatch Range near Park City. Part of the Charleston thrust fault ley, and the Saratoga area located at the north end of was reactivated during extensional collapse of the Sevier orogenic (Figure 1). Several other thermal springs also occur scattered belt about 40 to 20 mya (late Eocene to early Miocene); this early throughout and extend farther to the south. phase of extension occurred along the Deer Creek detachment The Warm Springs fault geothermal area extends about 3 miles fault, a major low-angle normal fault that accommodated 3 to 4 (4.8 km) in length and 0.8 mile (1.2 km) in width, lying along the miles (5-6 km) of west and southwest displacement (Constenius base of the Wasatch Range, just north of Salt Lake City. Beck’s and others, 2003). Strata of Mount Timpanogos are part of the Hot Spring, Wasatch Warm Springs, and Hobo Warm Springs 25,000-foot- (7600-m-) thick Oquirrh Group rocks on the upper occur along this segment of the Wasatch fault (Figure 1). (The plate of the Charleston-Nebo thrust sheet (Hintze, 2005). North term Warm Springs fault is a local name given to this section of of the Charleston-Deer Creek-Fort Canyon fault, Hintze (2005) the Wasatch fault.) Discharge temperatures in this system range indicated that age-equivalent strata in the Park City area are only from 108°F (42°C) at Wasatch Warm Springs, to 131°F (55°C) one-tenth as thick. at Beck’s Hot Spring (Klauk and Darling, 1984). The Crystal (Bluffdale) Hot Springs geothermal area is located Subsurface Lithology, Fracturing, and Alteration at the south end of the Salt Lake Valley, near the Utah State Prison, Parry and Bruhn (1986), Evans and others (1997), and Bruhn about 2 miles (3.2 km) north of the Traverse Mountains (Figure 1). and others (2005), described hydrothermally altered and me- Klauk and Darling (1984) reported that spring surface tempera- chanically deformed monzogranite and granodiorite of the Little tures vary between 131° and 183°F (55° and 84°C). Subsurface Cottonwood stock at Corner Canyon. Alteration and fracturing temperatures in excess of 185°F (> 85°C) have been reported in is most intense along the Wasatch-Fort Canyon fault zone and production wells ranging from about 600 to 1000 feet (183-305 decreases inward toward the intrusion, forming a shell or carapace m) in depth. Three production wells are currently available for on the south and west flanks of the intrusion that is several hun- geothermal-heated greenhouses and space heating for part of the dred feet thick. Altered rocks exposed at Corner Canyon formed Utah State Prison. One well is owned by the Utah Department of at estimated depths of 4.5 to 7.1 miles (7.2–11.4 km) and record Corrections (UDC) and dedicated to the prison heating system; inception of faulting on the Wasatch fault beginning about 17 the other two are owned by Bluffdale Flowers. A fourth well million years ago (Parry and Bruhn, 1986). Biek (2005a) showed owned by the prison was reportedly “re-discovered” after being the distribution of these altered rocks in the Lehi quadrangle im- “lost” about 20 years ago and may be available for future use. The mediately south of the well. The alteration assemblage grades springs normally issue from valley alluvium into several ponds. from greenish, highly altered rocks (phyllonite and cataclasite) When production wells are in operation, the surface springs and near the Wasatch and Fort Canyon faults to brownish, less altered ponds reportedly dry up. rocks toward the interior of the pluton. Saratoga Hot Springs issue from unconsolidated Quaternary The well penetrated alluvial deposits from the surface to about deposits along the northwest shore of Utah Lake in SE1/4SW1/4 60 feet (18 m) depth. From here the cuttings consisted of disag- section 25, T. 5 S., R. 1 W., SLBM in Utah County (figure 1). gregated igneous rock crystals and clay minerals that suggest fault Other hot springs, known locally as Crater Springs, issue beneath gouge. From about 120 feet (36 m) to about 160 feet (49 m) the Utah Lake about 0.5 mile (0.8 km) east of Saratoga Springs. well penetrated a suspected fault zone consisting of altered igneous Infrequent measurements since the early 1900s show that spring rock including foliated minerals, hematite, and magnetite. From temperatures have ranged from 100° to 111°F (38°- 44°C). The about 160 feet (49 m) downward to total depth of 1270 feet (387 springs are spatially related to the trend of the Utah Lake fault m) the well penetrated mostly monzogranite of the Little Cotton- zone (Mundorff, 1970). wood stock, described on the lithologic log as “. . . Green, gray, Corner Canyon Well Completion and white, and black phaneritic and porphyritic igneous rock composed Geophysical Logging of biotite, feldspar, and quartz; some chlorite and epidote?. . . Some xenoliths of limestone and volcanic rock fragments?” (see WaterPro contracted Mike Zimmerman Well Service to Blackett and others, in press). The log suggests that one or more drill and complete the Corner Canyon well. Zimmerman began fault zones were penetrated within the upper 160 feet (49 m) of drilling on December 29, 2007 and completed the drilling phase the well. The location of the Wasatch fault is marked by several of the well in early March 2008, completing an approximately fault scarps in the Corner Canyon area (Personius and Scott, 1992; 10-inch- (25.4-cm-) diameter well to a total depth of 1270 feet Biek, 2005b). The presence of chlorite and epidote suggests that (387 m). Zimmerman completed the well by installing a 10- the well penetrated the altered carapace of the Little Cottonwood inch- (25-cm-) diameter casing to 150 feet (46 m) depth, leaving stock, which is well exposed to the east in Corner Canyon. For a the interval from 150 feet (46 m) to total depth uncased. Dur- detailed description of cutting samples from the well and a geo- ing drilling, Zimmerman recorded mud temperatures of 132°F logic interpretation, see Blackett and others (in press). (56°C) at 980 feet (299 m) and 139°F (59°C) at total depth. On April 22, 2008, the lower 70 feet (21 m) of the well were tested Jordan Valley Geothermal Areas by first installing a packer at 1200 feet (366 m) and air lifting Three other geothermal areas are situated within the upper approximately 55 gallons per minute (gpm) (208 l/m) from the and lower Jordan River Valley region (Utah Valley and Salt Lake open hole below the packer for approximately seven hours. The Valley, respectively). They include the Warm Springs fault area temperature of this air-lifted water was 175°F (79°C), and pH and just north of downtown Salt Lake City, the Crystal-Bluffdale area electrical conductivity were 8.1 and 10,820 micro-Siemens per

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centimeter ( S/cm), respectively. The packer was removed, and the well was air-lifted again for approximately 24 hours, yielding approximately 100 gpm (380 l/m) of 185°F (85°C) water having pH of 7.7 and conductivity of 12,600 S/cm. Initial geophysical logging attempts by Utah Geological Survey (UGS) were unsuccessful because water temperatures ex- ceeded the design limits of the logging tools. As a result, WaterPro, along with their consultant, Loughlin Water Associates LLC, hired Schlumberger to obtain geophysical logs of the well. Schlum- berger recorded gamma ray, resistivity, self potential (SP), sonic, porosity, and caliper logs on March 5, 2008. A general summary of geophysical well logs is presented below. See Blackett and others (in press) for more details on the geophysical logging. Caliper: The caliper tool recorded major washouts, interpreted as fracture zones, in the Corner Canyon well through the following depth intervals: (1) from 150 to 178 feet (46–54 m); (2) from 225 to 242 feet (66–74 m); and (3) 350 to 380 feet (107–116 m). Sonic: The Sonic log somewhat mimics the caliper log, showing intervals of likely higher permeability, interpreted as fracture zones. Natural gamma (gamma ray): The dominant litho-type en- countered in the Corner Canyon well is intrusive “monzogranite” as described by Biek (2005a), which typically yields uniformly high gamma radiation. Wash-out zones, previously described, (150 to 178 feet [46–54 m] depth) containing clay alteration may be reflected in a small way on the gamma-ray log, though the lower gamma-ray values in this interval may simply reflect the interval’s larger borehole diameter. Figure 2. Temperature-depth profile of the Corner Canyon well. E-logs (resistivity): Resistivity logs show that the granite from 150 to 530 feet (46-162 m) has been disturbed and altered, presum- ably by faulting and fracturing. From 530 to 1220 feet (162-372 (144-152 m). Bottom-hole temperature was 195°F (90.6°C) at 1221 m), the granite is mostly undisturbed but with common 5- to 10- feet (372 m). Since no temperature variation was noted from 1194 foot (1.5- to 3-m) disturbed intervals. Altered and fractured zones, feet (364 m) to total depth, we are suspicious that the probe may indicated on the E-logs, may point to different parts of the altered have stopped at 1194 feet (364 m). carapace of the Little Cottonwood pluton that is exposed farther to the southeast in Corner Canyon (Biek, 2005a) and described Hydrochemistry and Stable Isotopes in detail by Parry and Bruhn (1986). It is also important to note Water samples were collected from the Corner Canyon well that resistivity is affected by temperature changes. during a 24-hour pump test on January 17, 2009. Three aliquots were collected in 1.18 pint (560 ml) polyethylene bottles as fol- Temperature Logging lows, (1) raw, unfiltered; (2) filtered (0.45µm [.000018 in]); (3) UGS personnel used a high-precision thermistor probe and filtered (0.45 µm [.000018 in]) and diluted 1:4 with deionized temperature-depth logging equipment to record a temperature-depth water. The samples and a deionized-water blank sample were profile of the well. Instrument characteristics and periodic calibra- analyzed by Thermochem Laboratory & Consulting Services in tions result in a temperature measurement precision of 0.018°F Santa Rosa, California. The results of Thermochem’s analyses (0.01°C), but convection within the well can reduce measurement indicate the water is of sodium-chloride type (Table 1). accuracy to ± 0.09°F (0.05°C). The first down-hole temperature The chemistry of the Corner Canyon well was compared to survey was done on April 3, 2008, when a maximum temperature other Wasatch Front geothermal systems and three fresh-water of 200°F (93°C) was recorded at a depth of 466 feet (142 m). A wells in Draper and the nearby city of Sandy (Blackett and others, blockage in the well at 906 feet (276 m) prevented the probe from in press). The Corner Canyon well major-ion water chemistry is reaching total depth. The temperature at 906 feet (276 m) was 196°F most similar to Ogden Hot Spring (Weber County), and relatively (91°C). Following this, drillers re-entered the well to remove the similar to Beck’s Hot Spring of the Warm Springs fault area, and blockage and develop and test pump the well. On June 19, 2008, fol- Udy Hot Spring, in northern Box Elder County. However, the lowing several weeks when the well was left undisturbed, a second silica content of the Corner Canyon well (179 mg/kg) is much temperature profile was recorded (figure 2). The static water-level higher than the other thermal springs in the comparison. measured with an electronic water-level sounding device was 85.6 The Corner Canyon well water yielded stable isotope ratios feet (26.1 m) below land surface. Temperatures were measured of hydrogen (D/H) and oxygen (18O/16O) of ‑116.9 and ‑14.88 ‰, to a depth of 1221 feet (372 m). Maximum temperature recorded respectively, which is slightly enriched in the heavier isotopes was 202°F (94.6°C) within the depth interval from 471 to 499 feet compared to wells in the principal aquifer in the Salt Lake Val-

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Table 1. Water chemistry for the Corner Canyon well, sampled 1/17/09. Discussion and Conclusions Analyte mg/kg Sodium 2320 The Corner Canyon water well penetrated a concealed, pre- Potassium 287 viously unknown geothermal system along the Wasatch front in Calcium 255 northern Utah. Borehole temperature, lithologic, and geophysical Magnesium 4.85 Boron 3.06 logs all suggest that fracture zones or faults intersected by the well Silica 179 in the upper approximately 500 feet (152 m) are likely producing Iron 1.20 the most geothermal water. Water produced from the well during Chloride 3860 flow-testing yielded sodium-chloride-type water of moderate sa- Sulfate 209 linity (7360 mg/kg total dissolved solids) at temperatures of about - Total Alkalinity (as HCO3 ) 244 195°F [90.6°C]). Silica content is anomalously high and applying 2- Carbonate Alkalinity (as CO3 ) <2 geothermometry to this and other chemical constituents suggest - Bicarbonate Alkalinity (as HCO3 ) 244 reservoir temperatures ranging from 302 to 358°F (150-181°C). TDS (calculated) 7360 The geothermal system occurs at the junction of the north- Lab measured pH 6.75 trending Wasatch Range and the southwest-trending Traverse 1 Stable Isotopes of Water ‰ Mountains near a segment boundary of the Wasatch fault. Near 2H δ -116.94 the well, the Wasatch fault makes an abrupt bend to the east, where δ18O -14.88 the Wasatch fault links with the east-trending Fort Canyon fault 1 Measurements relative to V-SMOW = 0 with uncertainty of +/- 1.0% for δ 2H and +/- 0.1% for δ 18O. V-SMOW = Vienna distribution of water sample representing (a reactivated part of the Charleston thrust fault and Deer Creek Standard Mean Ocean Water. detachment fault). Rocks south of the Fort Canyon fault have experienced several episodes of deformation. Pennsylvanian- ley. The δ18O “shift” to less negative values often observed in age sandstone of the Oquirrh Group and overlying Eocene to geothermal systems (Clark and Fritz, 1997) is not as pronounced Oligocene volcanic rocks in the Traverse Mountains are highly in the Corner Canyon Well as it is in other thermal waters of Utah, fractured and locally pulverized. Monzogranite of the Little Cot- such as Crystal-Madsen, Utah Hot Spring, and Saratoga Springs tonwood stock exposed in the footwalls of the Wasatch and Fort (Cole, 1983; Mayo and Klauk, 1991). Cole (1983) suggested in- Canyon faults also exhibits evidence of significant extensional termediate isotopic concentrations, such as observed in the Corner deformation. As exposed in Corner Canyon, and encountered Canyon well, may result from geothermal waters mixing with fresh in the discovery well, the outer several hundred feet of the intru- ground water. A water sample collected from a borehole through sion show mechanical and hydrothermal alteration, including Little Cottonwood Stock granite in , the cataclasis, intense fracturing, and low-temperature metamorphic same pluton type in which the Corner Canyon well is completed, mineral assemblages. may be one end member of such a mixing relationship. Indeed, We speculate that the Fort Canyon fault and the southern conservative mixing calculations using 14% highly saline Crystal part of the Salt Lake segment of the Wasatch fault may serve as (Madsen) Hot Spring water with 86% fresh well water yields a conduits for southward and westward groundwater flow off of water of similar chemical composition, with the exception of the southern flank of the Little Cottonwood Stock. The relatively silica, to the Corner Canyon well. shallow, fresh ground water may be mixing with a deep highly Standard chemical geothermometer results are shown on saline geothermal fluid along these conduits to produce the water Table 2 and described in more detail in Blackett and others (in found in the Corner Canyon well. press). A wide range of values are noted, but the most likely Land status in the vicinity of the Corner Canyon water well is indicators of reservoir temperature would be the chalcedony mainly private ownership along the urban fringe of Draper City. geothermometer (302°F [150°C]) and the potassium-magnesium The urbanized area lies less than 500 feet (150 m) west of the well. geothermometer (358°F [181°C]). Lands within the Uinta and Wasatch-Cache National Forests lie about 1000 feet (300 m) east of the well site. The central part of Table 2. Chemical geothermometry applied to Corner Canyon well water the Wasatch Range east of the Salt Lake Valley and the northern analyses. Equilibrium part of Utah Valley consists of three Forest Service wilderness Geothermometer1 Notes Temperature areas (Mt. Timpanogos, Lone Peak, and Twin Peaks wilderness (°C) areas) comprising nearly 61,000 acres. 1. quartz no loss 173 2. quartz max loss T=0-250 C 162 3. chalcedony 150 Acknowledgements 4. α-christobalite 123 We thank David A. Gardner, Assistant General Manager 5. β-christobalite 73 6. amorphous silica 49 of WaterPro, Inc., for providing access to the well and cutting 7. Na/K - Fournier 212 samples. We also thank Hugh Klein and William Loughlin of 8. Na/K - Truesdell T>150°C 236 Loughlin Water Associates, LLC for down-hole information 9. Na-K-Ca β=4/3 235 and other assistance with this project. Joseph Moore, Ph.D., of 10. K-Mg 181 the Energy and Geoscience Institute at the University of Utah 1References for geothermometers are as follows: 1 through 9 from Fournier (1981) provided valuable guidance in interpretation of data presented and 10 from Giggenbach (1988). in this paper.

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References Hecker, Suzanne, 1993. “Quaternary tectonics of Utah with emphasis on earthquake-hazard characterization.” Utah Geological Survey Bulletin Biek, R.F., 2005a. “Geologic map of the Lehi quadrangle and part of the 127, 36 p., 3 appendices, 2 plates. Timpanogos Cave quadrangle, Salt Lake and Utah Counties, Utah.” Utah Geological Survey Map 210, 2 plates, scale 1:24,000. Hintze, L.F., 2005. “Utah’s spectacular geology – how it came to be.” Brigham Young University Geology Studies, Special Publication 8, 203 p. Biek, R.F., 2005b. “The Traverse Mountains – new geologic maps and explosive suburban growth.” Utah Geological Survey, Survey Notes, Hintze, L.F., G.C. Willis, D.Y.M. Laes, D.A. Sprinkel, and K.D. Brown, v. 37, no. 2, p. 1-5. 2000. “Digital geologic map of Utah.” Utah Geological Survey Map 179 DM, scale1:500,000. Blackett, R.E., J.L. Jordan, Kevin Thomas, Janae Wallace, and R.F. Biek, in press. “A concealed geothermal system near Corner Canyon, Salt Lake Klauk, R.H., and Rikki Darling, 1984. “Low-temperature geothermal assess- County, Utah.” in Tripp, B.T., Krahulec, Ken, and Jordan, J.L., editors. ment of the Jordan Valley, Salt Lake County, Utah.” Utah Geological “Geology and geologic resources and issues of western Utah.” Utah and Mineral Survey Report of Investigation 185, 160 p. Geological Association Publication 38. Machette, M.N., 1992. “Surficial geologic map of the Wasatch fault zone, Bruhn, R.L., C.B. DuRoss, R.A. Harris, and W.R. Lund, 2005. “Neotecton- eastern part of Utah Valley, Utah County and parts of Salt Lake and Juab ics and paleoseismology of the Wasatch fault, Utah.” in Pederson, J., Counties, Utah.” U.S. Geological Survey Miscellaneous Investigations and Dehler, C.M., editors. “Interior Western United States.” Geological Series Map I-2095, scale 1:50,000. Society of America Field Guide 6, p. 231-250. Machette, M.N., S.F. Personius, and A.R. Nelson, 1992. “Paleoseismol- Cole, D.R., 1983. “Chemical and isotopic investigations of warm springs ogy of the Wasatch fault zone – a summary of recent investigations, associated with normal faults in Utah.” Journal of Volcanology and interpretations, and conclusions.” in Gori, P.L., and W.W. Hays, edi- Geothermal Research, v. 16, p. 65-98. tors. “Assessment of regional earthquake hazards and risk along the Wasatch Front, Utah.” U.S. Geological Survey Professional Paper Clark, I., and Fritz, P., 1997. “Environmental Isotopes in Hydrogeology.” 1500-A, 71 p. Boca Raton, Lewis Publishers, 352 p. Mayo, A.L., and R.H. Klauk, 1991. “Contributions to the solute and isotopic Constenius, K.N., R.P. Esser, and P.W. Layer, 2003. “Extensional collapse of groundwater geochemistry, Antelope Island, Great Salt Lake, Utah.” the Charleston-Nebo salient and its relationship to space-time variations Journal of Hydrology, v. 127, p. 307-335. in Cordilleran orogenic belt tectonism and continental stratigraphy.” in Raynolds, R.G., and R.M. Flores, editors. “Cenozoic Systems of the Mundorff, J.C., 1970. “Major thermal springs of Utah.” Utah Geological and Rocky Mountain Region.” Rocky Mountain Section, Society of Eco- Mineral Survey Water Resources Bulletin 13, 60 p. nomic Paleontologists and Mineralogists, p. 303-353. Murphy, P.J., and J.W. Gwynn, 1979. “Geothermal in­vestigations at Crystal Davis, F.D., 1983. “Geologic map of the central Wasatch Front, Utah.” Utah Hot Springs, Salt Lake County, Utah.” Utah Geological and Mineral Geological and Mineral Survey Map 54-A, scale 1:100,000. Survey Report of In­vestigation 139, 91 p. Evans, J.P., W.A. Yonkee, W.T. Parry, and R.L. Bruhn, 1997. “Fault-related Parry, W.T., and R.L. Bruhn, 1986. “Pore fluid and seismogenic characteristics rocks of the Wasatch normal fault.” in Link, P.K., and B.J. Kowallis, edi- of fault rock at depth on the Wasatch fault, Utah.” Journal of Geophysical tors. “Mesozoic to Recent geology of Utah.” Brigham Young University Research, v. 91, no. B1, p. 730-744. Geology Studies v. 42, part II, p. 279-297. Personius, S.F., and W.E. Scott, 1992. “Surficial geologic map of the Salt Fournier, R.O., 1981. “Application of water geochemistry to geothermal Lake City segment and parts of adjacent segments of the Wasatch systems.” in Rybach, L., and L.J.P. Muffler, editors. “Geothermal sys- fault zone, Davis, Salt Lake, and Utah Counties, Utah.” U.S. Geo- tems – principals and case histories.” New York, New York, John Wiley logical Survey Miscellaneous Investigations Series Map I-2106, scale and Sons, p. 109-143. 1:50,000. Giggenbach, W.F., 1988. “Geothermal solute equilibria – derivation of Na- Schwartz, D.P., and K.J. Coppersmith, 1984. “Fault behavior and characteristic K-Mg-Ca geoindicators.” Geochimica et Cosmochimica Acta, v. 52, p. earthquakes – examples from the Wasatch and San Andreas fault zones.” 2749-2765. Journal of Geophysical Research, v. 89, no. B7, p. 5681-5698.

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