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USGS2023

Tungsten resources of the northern Rocky Mountains, Montana and Idaho— A synthesis and quantitative assessment of skarn-hosted resources

Mineral resource assessments performed by the U.S. Geological Survey provide a synthesis of available information about the location of known and suspected mineral deposits. This study focuses on skarn-hosted tungsten resources in the northern Rocky Mountain region of east-central Idaho and western Montana which have seen moderate tungsten trioxide production in the past from a variety of mineralization styles including skarn, vein and replacement, and wolframite-quartz veins. The area’s geology is dominated by large Cretaceous and Tertiary plutons that are emplaced into a belt of Mesoproterozoic to Permian sedimentary rock and affected by tectonism related to the Sevier and later Laramide orogenies. Known tungsten skarn mineral sites are associated with contacts between Cretaceous plutons and calcareous and argillaceous sedimentary or metasedimentary rocks, including two skarn deposits in Montana (Calvert and Browns Lake) that are consistent with an updated grade and tonnage model. This study (1) delineates permissive tracts where undiscovered tungsten skarn deposits may occur within 1 kilometer of the surface; (2) presents a tungsten mineral site dataset from a variety of public sources; (3) evaluates currently available geochemical, geophysical, and radiometric age data in support of tract delineation; (4) provides probabilistic estimates of the amount of tungsten and tungsten-mineralized rock that could be contained in undiscovered deposits within one major tract; (5) estimates the value of total undiscovered deposits using economic filter analysis; and (6) provides a synthesis of metallogenic controls on regional tungsten skarn and granitoid-related mineral deposits. Two permissive tracts were delineated: the Great Falls tectonic zone (GFTZ)-Cretaceous tract, for which a quantitative assessment was performed, and the Bitterroot tract, which was assessed in a qualitative manner. The quantitative three-part assessment, conducted in August 2019, indicates that undiscovered tungsten resources might exist in skarn-type deposits within the study area. Using a negative binomial function, a mean of 4 undiscovered deposits was calculated from panel estimates. Simulation results that combine an updated grade and tonnage model with estimates of undiscovered deposits include the amounts of ore and contained tungsten trioxide at different levels of uncertainty. A mean of 250,000 metric tons and median of 200,000 metric tons contained tungsten trioxide was calculated for the undiscovered deposits within the GFTZ-Cretaceous tract. The value of undiscovered deposits was estimated using a new economic filter that considers factors such as mine type, deposit depth, deposit geometry, metallurgical recovery rate, cutoff grade, and tract area. A review of the regional Archean to Paleogene geology suggests that ore metal (copper, molybdenum, and tungsten) variations in intrusion-related deposits of Montana and Idaho may be controlled by a number of factors including the age and composition of underlying basement terranes, depth of emplacement, pluton chemistry and degree of fractionation, redox conditions, and aqueous fluid-melt partition coefficients.

Idaho, Montana↗
USGS1952

Reconnaissance of radioactive rock of the Hudson Valley and Adirondack Mountains, New York

In August 1949 a carborne reconnaissance for radioactivity was made along 3,750 miles of road in the Paleozoic rocks of the Hudson Valley and the pre-Cambrian rocks of the Adirondack Mountains in eastern and central New York state. In the Paleozoic rocks the average radioactivity of the most strongly radioactive rocks is 0.003 percent equivalent uranium. The area underlain by pre-Cambrian rocks in the northwestern and southeastern parts of the Adirondacks contain the greatest concentration of abnormally radioactive rocks and glacial materials. This radioactivity is most apparent near the contacts of the igneous and metamorphic rocks where the average range of equivalent uranium content is estimated to be 0.003-0.004 percent. Pegmatites contain as much as 0. 043 percent uranium and 0.62 percent thorium. Iron slag containing 0.030 percent equivalent uranium was found near Moriah Center, and uranium and thorium in iron minerals have contributed to the radioactivity at several other abnormally radioactive localities.

New York↗
USGS1953

Airborne radioactivity survey of the Aspen Mountain area, Sweetwater county, Wyoming

The accompanying map shows the results of an airborne radioactivity survey covering 700 square miles in the Aspen Mountain area, Sweetwater county, Wyoming. The survey was made by the U.S. Geological Survey, October 22, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomaly that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the surrounding area. Any particular anomaly, therefore, may represent either slightly greater-than-average radioactivity over an area of a few thousand square feet, or high radioactivity over an area of a few hundred square feet. The radioactivity anomalies shown on the accompanying map indicate localities of more-than-average radioactivity, and therefore, suggest areas in which uranium or thorium deposits are more likely to occur.

Wyoming↗
USGS1953

Geology of the Pine Mountain quadrangle, Mesa county, Colorado

The Pine Mountain quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from Paleozoic to Quaternary. Over mush of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confines to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in sizer from irregular masses containing only a few ton of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Colorado↗
USGS2005

Sampling protocol for monitoring abiotic and biotic characteristics of mountain ponds and lakes

This document describes field techniques and procedures used for sampling mountain ponds and lakes. These techniques and procedures will be used primarily to monitor, as part of long-term programs in National Parks and other protected areas, the abiotic and biotic characteristics of naturally occurring permanent montane lentic systems up to 75 ha in surface area. However, the techniques and procedures described herein also can be used to sample temporary or ephemeral montane lentic sites. Each Standard Operating Procedure (SOP) section addresses a specific component of the limnological investigation, and describes in detail field sampling methods pertaining to parameters to be measured for each component.

Techniques and Methods↗
USGS2001

Controls of stream chemistry and fish populations in the Neversink watershed, Catskill Mountains, New York

The Neversink Watershed Study was initiated in 1991 to develop an understanding of the key natural processes that control water quality within the forested, 166 km 2 (64 mi 2 ), Neversink River watershed; part of the New York City drinking water supply system, in the Catskill Mountain region of New York. The study entailed (1) hydrological investigations of water movement from the atmosphere to streams, (2) biogeochemical investigations of nitrogen and calcium, important nutrients in forest and aquatic ecosystems whose availability has been altered by acidic deposition, (3) an investigation of elevational patterns in atmospheric deposition, and (4) fisheries investigations to determine the relative importance of physical habitat and acidic deposition in controlling the abundance and diversity of fish species in the watershed. This report summarizes the results of these investigations, which have also been presented, in detail, in peer-reviewed technical articles and reports that are cited throughout the text.

New York↗
USGS2001

Seepage investigation for Leap, South Ash, Wet Sandy, and Leeds creeks in the Pine Valley Mountains, Washington County, Utah, 1998

Seepage loss-gain data were collected along four creeks (Leap, South Ash, Wet Sandy, and Leeds) that drain the eastern flank of the Pine Valley Mountains in southwestern Utah. Streamflow was measured at a minimum of eight sites on each of the four creeks during each of three (four on South Ash) seepage investigations at higher streamflows in May and June, and at lower streamflows during August, October, and November 1998. Only two reaches on Leap and Leeds Creeks showed a significant reversal of loss or gain trends between high and low streamflow where the difference in streamflow exceeded the measurement error. Error analyses were computed both for individual reaches between consecutive measurement sites and for composite reaches between specified, nonconsecutive measurement sites to determine if seepage losses or gains exceed the error associated with measurement of streamflow. Computed losses or gains at 31 individual reaches exceed the normalized measurement error; 16 were along channel reaches that traverse unconsolidated deposits, 7 were associated with reaches that traverse sedimentary rocks other than Navajo Sandstone, 6 were associated with reaches that traverse the Navajo Sandstone, and 2 were associated with reaches that traverse rocks of igneous origin. Composite reaches that encompass the outcrop of one of four hydrogeologic units (Navajo Sandstone, unconsolidated deposits, igneous rocks, or sedimentary rocks other than Navajo Sandstone) were used to compute the loss or gain based on the amount measured at the upstream and downstream nonconsecutive sites. For composite reaches that traverse outcrops of Navajo Sandstone, less water was measured at (or near) the downstream contact than at (or near) the upstream contact for 11 of the 13 seepage investigations. Of those 11 investigations with computed losses, the normalized difference (N d) was greater than the normalized error (N e ) for 6 investigations and confirms that a source of recharge to the Navajo Sandstone is seepage loss from the measured streams.

Utah↗
USGS2002

Three-dimensional measurements of flow in uncased wells completed in basalt, Mountain Home Air Force Base, Idaho, March 2000

Several ground-water monitoring wells on the Mountain Home Air Force Base in southwestern Idaho were constructed in February 2000 to replace existing monitoring wells that became ineffective as a result of declining water levels. Upon completion of the replacement wells, borehole geophysical logs were collected, including natural gamma radiation, electromagnetic induction, caliper, fluid temperature, and resistivity. A prototype borehole acoustic doppler velocimeter (B-ADV) was used to make experimental three-dimensional measurements of lateral and vertical flow in two of the replacement wells, MW11–2 and MW3–2, each 450 feet deep, to better understand ground-water flow in the basalt underlying this area. Measurements indicated two independent flow zones in each well: unit B, from about 380 to about 415 feet below land surface, and unit C, from about 415 to about 430 feet below land surface. In each well, direction of flow in unit B was north-northwest toward Canyon Creek and, in unit C, south-southwest toward the Snake River. Measurements also indicated downward intraborehole flow in both wells. Unit B appeared to represent a local-scale flow regime; unit C appeared to represent a regional flow regime. This information suggests the existence of a complex three-dimensional hydrogeologic setting that cannot be discriminated easily on conventional waterlevel maps. Although data from only two wells are insufficient to construct a conceptual model of the ground-water flow regime, these experimental results demonstrate the capability of the B-ADV to obtain detailed flow measurements that, combined with data from other types of geophysical logs, discrete measurements of hydraulic head, and water chemistry, would aid in future studies and management of the ground-water resources, including contaminant transport and remediation.

Idaho↗
USGS1976

Maps showing ground-water conditions in the Concho, St. Johns, and White Mountains areas, Apache and Navajo Counties, Arizona, 1975

The Concho, St. Johns, and White Mountains areas cover about 2 ,300 sq mi in eastern Arizona. Ground water is present in several aquifers that are made up of one or more formations. The maps show ground-water conditions in the Coconini aquifer; in the Triassic, Cretaceous, and Tertiary rocks; and in the alluvium and basaltic rocks. Information on the maps includes depth to water, altitude of the water level, chemical quality of the water, irrigated area, and hydrographs of the water level in selected wells. Scale 1:125,000. (Woodard-USGS).

Arizona↗
USGS1978

Geohydrologic data from the Jemez Mountains and vicinity, north-central New Mexico

The Jemez Mountains volcanic region, on the west margin of the Rio Grande rift in north-central New Mexico, is the site of studies for power development from geothermal heat. This report summarizes geohydrologic data to provide background information relative to the geothermal exploration and to investigate the usefulness of hydrology in assessment of the geothermal resource. Eleven tables present chemical, temperature, discharge , and other data for springs, wells, and streams. Accompanying figures show locations of the data points and present temperature profiles and geophysical logs for selected wells. (Woodard-USGS)

Water-Resources Investigations Report↗
USGS1978

Sediment transport by the White River into Mud Mountain Reservoir: Washington, June 1974-June 1976

This reconnaissance evaluation of the sediment transport by the White River into the Mud Mountain Reservoir, in Washington, during the period June 1974-June 1976 showed that the river transported 430,000 tons of suspended sediment into the reservoir during the first year of the study and 1,400,000 tons in the second year. Daily mean suspended-sediment concentrations generally were less than 500 milligrams per liter; the highest daily mean concentration was 6,200 milligrams per liter on December 1, 1975. A good relation exists between daily suspended-sediment discharge and daily mean water discharge except during periods of runoff from glacial melt. Data from samples obtained by the use of the Helley-Smith bedload sampler indicate that the bedload measured using the sampler is about 4 percent of the suspended-sediment discharge. Potential deposition in the reservoir was estimated at 750 acre-feet during the 2 years of study. (Kosco-USGS)

Washington↗
USGS1982

Effects of volcanic ash on the benthic environment of a mountain stream, northern Idaho

The May 18, 1980, eruption of Mount St. Helens deposited about 15 millimeters of volcanic ash on the Big Creek basin in northern Idaho. Much of the uncompacted ash remained on hillsides a year after the eruption. Physical and chemical analyses of water samples from Big Creek collected from December 1980 to December 1981 showed no anomalies attributable to ash. Qualitative collections showed benthic invertebrates to be abundant and diverse in Big Creek. Experiments conducted in an unimpacted mountain stream revealed a small quantity of volcanic ash may be beneficial not detrimental to invertebrate communities. Benthic invertebrates were most abundant on ash-covered artificial substrates, with detritovores dominating the communities on all substrates. (USGS)

Idaho↗
USGS1982

Streamflow losses to Madison Group rocks in the Little Belt and Big Snowy Mountains, Montana

Four streams originating in the Little Belt and Big Snowy Mountains in central Montana were measured in 1975 to determine streamflow losses across outcrops of the Madison Group (Mississippian age). Based on streamflow data obtained for 39 months at two streamflow-gaging stations on the Middle Fork Judith River, the average daily loss was 9.1 cubic feet per second or about 6,600 acre-feet per year. Seepage measurements on other stream reaches indicated losses of 7.6 cubic feet per second on the south Fork Judith River, 9.2 cubic feet per second in Yogo Creek, as much as 64 cubic feet per second in Dry Wolf Creek, and about 60 cubic feet per second in Rock Creek. (USGS)

Montana↗
USGS1983

Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico

Area 61 is located on the Colorado-New Mexico boundary in Huerfano and Las Animas Counties, Colorado, and Colfax County, New Mexico, and includes the Raton Mesa coal region. The 5 ,900-square-mile area is an asymmetrical structural trough bounded by the Rocky Mountains on the west and the Great Plains on the east. The area is drained by the Huerfano, Apishapa, Purgatoire, and Canadian Rivers (and their tributaries), all tributary to the Arkansas River. The principal coal-bearing formations are the Vermejo Formation of Late Cretaceous age and the Raton Formation of Late Cretaceous and Paleocene age. Much of the coal in the area is of coking quality, important to the metallurgical industry. Topographic relief in the area is greater than 8,700 feet, and this influences the climate which in turn affects the runoff pattern of area streams. Summer thunderstorms often result in flash floods. Virtually all geologic units in the region yield water. Depth to ground water ranges from land surface to 400 feet. Surface and ground water in the area contain mostly bicarbonate and sulfate ions; locally in the ground water, chloride ions predominate. Potential hydrologic problems associated with surface coal mining in the area are water-quality degradation, water-table decline, and increased erosion and sedimentation. (USGS)

Water-Resources Investigations Report↗
USGS1987

Hydrologic analysis of two headwater lake basins of differing lake pH in the west-central Adirondack Mountains of New York

Hydrologic analysis of two headwater lake basins in the Adirondack Mountains, New York, during 1980-81 indicates that the degree of neutralization of acid precipitation is controlled by the groundwater contribution to the lake. According to flow-duration analyses, daily mean outflow/unit area from the neutral lake (Panther Lake, pH 5-7) was more sustained and contained a higher percentage of groundwater than that of the acidic lake (Woods Lake, pH 4-5). Outflow recession rates and maximum base-flow rates, derived from individual recession curves, were 3.9 times and 1.5 times greater, respectively, in the neutral-lake basin than in the acidic-lake basin. Groundwater contribution to lake outflow was also calculated from a lake-water budget; the groundwater contribution to the neutral lake was about 10 times greater than that to the acidic lake. Thick sandy till forms the groundwater reservoir and the major recharge area in both basins but covers 8.5 times more area in the neutral-lake basin than in the acidic-lake basin. More groundwater storage within the neutral basin provides longer contact time with neutralizing minerals and more groundwater discharge. As a result, the neutral lake has relatively high pH and alkalinity, and more net cation transport. (USGS)

Water-Resources Investigations Report↗
USGS1984

Conceptual hydrologic model of flow in the unsaturated zone, Yucca Mountain, Nevada

The unsaturated volcanic tuffs beneath Yucca Mountain, Nevada, are being evaluated as a host rock for a potential repository for high-level radioactive waste. A conceptual hydrologic model is proposed to describe the flow of fluids through these rocks. Thickness of the unsaturated zone is about 500 to 750 meters and consists of three welded units interlayered with two nonwelded units. Compared to nonwelded units, welded units have low matrix porosities and permeabilities, high fracture densities, and high bulk hydraulic conductivities. The principal repository area is bounded by normal fault zones. Of the average annual precipitation of 150 millimeters per year, 0.5 to 4.5 millimeters per year becomes net infiltration. Percolation through the matrix of the welded units is principally vertical and is less than 1 millimeter per year. Percolation through nonwelded units occurs both vertically and laterally and has variable rates (0.1 to 100 millimeters per year). Fracture flow is predominant in the uppermost welded unit during intense pulses of infiltration, but is insignificant in the welded unit that forms the potential host rock. Lateral flow in the upper nonwelded unit, enhanced by existence of a capillary barrier, probably is the factor controlling the low fluxes in the host rock and relatively high fluxes in the structural features. (USGS)

Water-Resources Investigations Report↗
USGS1985

Hydrogeology and water quality of the Catoctin Mountain National Park Area, Frederick County, Maryland

The Catoctin Mountain National Park area, located in the Blue Ridge physiographic province of central Maryland, is characterized by high local relief, an average annual precipitation of 44 inches, and stony soils underlain by weathered and fractured metamorphic rocks. The park is mostly forested land and includes several camps and roads. The groundwater reservoir consists of regolith and underlying fractured bedrock and is recharged by precipitation. Discharge from the groundwater flow system is mainly to nearby streams adjacent to areas of recharge. Approximately 56% of annual streamflow is contributed by groundwater. Wells located at Camp Round Meadow and Staff Quarters No. 5 can sustain pumping rates of 45 to 60 gal/min for several hours, with drawdown of 40 to 50 ft. Water quality samples from wells, springs, and streams indicate that groundwater is slightly affected by septic waste and road salt. Groundwater in remote areas is not affected by either source. Concentrations of chloride from road salt and concentrations of nitrate plus nitrite (as N) were below U.S. EPA drinking water limits in all groundwater and surface water samples.

Maryland↗
USGS1993

Hydrogeology, geochemistry, and quality of water of The Basin and Oak Spring areas of the Chisos Mountains, Big Bend National Park, Texas

Test drilling near two sewage lagoons in The Basin area of the Chisos Mountains, Big Bend National Park, Texas, has shown that the alluvium and colluvium on which the lagoons are located is not saturated in the immediate vicinity of the lagoons. A shallow aquifer, therefore, does not exist in this critical area at and near the lagoons. Should seepage outflow from the lagoons occur, the effluent from the lagoons might eventually be incorporated into shallow ground water moving westward in the direction of Oak Spring. Under these conditions such water could reach the spring. Test borings that bottomed in bedrock below the alluvial and colluvial fill material are dry, indicating that no substantial leakage from the lagoons was detected. Therefore, no contaminant plume was identified. Fill material in The Basin does not contain water everywhere in its extensive outcropping area and supplies only a small quantity of ground water to Window Pouroff, which is the only natural surface outlet of The Basin. Oak Spring, which is almost 2 miles downgradient from the lagoons, is the sole source of water for The Basin the principal tourist area in Big Bend National Park. Test drilling in the Oak Spring area revealed that the aquifer in the immediate vicinity of Oak Spring is a 5-foot thick sand bed hydraulically confined above and below by relatively thick, compact clay. The sand bed might be bounded locally by faults to the east and west of the spring. The test drilling and seismic surveys in the area also established the existence of a thick, extensive, surficial layer of colluvium consisting of large rhyolite boulders. The colluvial layer, which overlies sedimentary bedrock containing the Oak Spring aquifer, was unsaturated at the borehole sites. Information from drilling and from hydrogeologic observation indicates that the water from Oak Spring originates as precipitation in the Oak Spring area west of The Basin, with possibly a contribution originating as discharge from The Basin. The rhyolite boulder field in the Oak Spring area, which includes talus from Vernon Bailey Peak, is an effective receptacle for rapid recharge of precipitation. This water could then be efficiently routed into the Oak Spring aquifer in places to the east of Oak Spring where any shallow ground water in the boulder field might enter the subcropping truncated aquifer. Water-chemistry data, hydrochemical facies, and isotopic data also indicate that water from Oak Spring originates principally from precipitation onto the land surface of the Oak Spring area. Tritium data indicate that Oak Spring water is "modern," with an average age of recharge less than 14 years. The flow rates recorded almost continuously at Oak Spring beginning in December 1986 show a close relation between precipitation and discharge. The highest recorded spring flow of 167 gallons per minute in December 1986 is attributed to record high precipitation in the area during 1986. The lowest recorded flow of 22.4 gallons per minute, in December 1989, followed a period of 20 out of 26 months of below-normal precipitation. Flow at Oak Spring typically lags behind precipitation by about 1 month. This fairly rapid response indicates the spring is fed by a shallow aquifer having good permeability and effective recharge areas with the ability to absorb precipitation rapidly.

Texas↗