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USGS1978

Map showing anomalous silver distribution in stream sediment concentrates, Hillsboro and San Lorenzo quadrangles, exclusive of the Black Range Primitive Area, Sierra and Grant Counties, New Mexico

This map shows the distribution of anomalous silver in the nonmagnetic (NM-1) sample fraction plotted on a base which includes sample localities, topography, and generalized geology from Hedlund (1975a, b). It is part of a series of maps for several metals that accompany this folio. Distributions of silver values are shown on the accompanying histograms.

New Mexico↗

USGS2004

Sources of water to the Rio Grande upstream from San Marcial, New Mexico

The Rio Grande watershed is a complex hydrologic system that includes numerous tributaries, inflow from transmountain diversions, irrigation diversions, agricultural return lows, reservoirs, and ground-water inflows and outflows. Many people depend on and are affected by the Rio Grande, which is the largest river of the surface-water system draining the Rio Grande watershed. To provide information to further the understanding of the Rio Grande surface-water system, the U.S. Geological Survey, in cooperation with the City of Albuquerque, evaluated streamflow data computed by the U.S. Geological Survey at 60 streamflowgaging stations. This fact sheet examines the sources of water to the Rio Grande and the "water balance" of the Rio Grande surface-water system upstream from San Marcial, New Mexico, by comparing the mean annual discharge (streamflow) at different stations.

Fact Sheet↗

USGS2008

Review of Available Water-Quality Data for the Southern Colorado Plateau Network and Characterization of Water Quality in Five Selected Park Units in Arizona, Colorado, New Mexico, and Utah, 1925 to 2004

Historical water-quality data in the National Park Service Southern Colorado Plateau Network have been collected irregularly and with little followup interpretation, restricting the value of the data. To help address these issues, to inform future water-quality monitoring planning efforts, and to address relevant National Park Service Inventory and Monitoring Program objectives, the U.S. Geological Survey, in cooperation with the National Park Service, compiled, reviewed, and summarized available historical water-quality data for 19 park units in the Southern Colorado Plateau Network. The data are described in terms of availability by major water-quality classes, park unit, site type, and selected identified water sources. The report also describes the geology, water resources, water-quality issues, data gaps, and water-quality standard exceedances identified in five of the park units determined to be of high priority. The five park units are Bandelier National Monument in New Mexico, Canyon de Chelly National Monument in Arizona, Chaco Culture National Historical Park in New Mexico, Glen Canyon National Recreation Area in Arizona and Utah, and Mesa Verde National Park in Colorado. Statistical summaries of water-quality characteristics are presented and considerations for future water-quality monitoring are provided for these five park units.

Scientific Investigations Report↗

USGS1997

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas: Fish communities at selected sites, 1993-95

Fish communities at 10 sites in the Rio Grande Basin were sampled during low-flow periods between 1993 and 1995 as part of the U.S. Geological Survey National Water-Quality Assessment Program. The ecology of fish communities is one of several lines of evidence used to characterize water-quality conditions. This report describes the fish communities at selected sites in the Rio Grande Basin and relates the structure of these fish communities to the physical and chemical characteristics of the streams. Twenty-nine species of fish representing 10 families were identified in 25 samples collected during this study. Species richness ranged from 1 to 13. Cluster analysis of the 25 samples collected during this study delineated four groups of sites that were based on the similarity of the fish communities. The first two groups were individual sites with low species richness. The third group contained the most samples, and the fourth group consisted of samples from the Rio Grande at Isleta, New Mexico, and the Rio Grande at El Paso, Texas. The shift in community structure of samples from group 3 to group 4 reflects changes from predominantly coldwater fishes to warmwater fishes. Four metrics of biotic integrity (percentages of introduced individuals, omnivores, tolerant individuals, and anomalies) were used in this study to provide a broad overview of the community structure. The relative percentages of introduced species at the Rio Grande near Del Norte, Colorado; Saguache Creek near Saguache, Colorado; Rio Grande below Taos Junction Bridge, near Taos, New Mexico; and Rio Grande at Isleta are indicative of biological stress on the communities at these sites. The dominance of omnivores in samples from the Rio Grande below Taos Junction Bridge, near Taos; Rio Chama near Chamita, New Mexico; Rio Grande at Isleta; and Rio Grande at El Paso is an indication of environmental stress at these sites. In 1995, tolerant species accounted for the entire fish community at the Rio Grande at Isleta. In all samples the occurrence of anomalies was less than 2 percent of the individuals, with the exception of the sample from the Rio Grande at Isleta. On the basis of the relative percentages of introduced individuals, omnivores, tolerant individuals, and anomalies, the biotic integrity at the Rio Grande at Isleta appears to be the most impaired of all sites and shows indications of potential chemical and physical perturbations. Fish communities from three reaches at the Santa Fe River above Cochiti Lake, New Mexico, and the Rio Grande at Isleta were sampled in 1995 to assess small-scale spatial patterns in the structure of fish communities. The spatial pattern at these sites might be associated with natural variability of the fish communities or with the presence of habitat features such as pools. The total number of individuals and relative abundance in a sample varied at sites sampled yearly during this study. All sites, with the exception of the Rio Grande near Del Norte, had a decline in total number of individuals in a sample. The temporal decline in the total number of individuals at these site might be associated with the natural variability within the fish communities.

Colorado, New Mexico, Texas↗

USGS2011

Locations and attributes of wind turbines in Colorado, 2009

The Colorado wind-turbine data series provides geospatial data for all wind turbines established within the State as of August 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, and county. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, year the facility went online, and development status of wind facility. Turbine locations were derived from August 2009 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program; the photographs have a positional accuracy of about + or - 5 meters. The location of turbines under construction during August 2009 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas currently (2011) in development by the U.S. Geological Survey. The Energy Atlas will synthesize data on existing and potential energy development in Colorado and New Mexico and will include additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools will be included in the Energy Atlas. The format of the Energy Atlas will facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

Data Series↗

USGS2019

Geomorphic survey of North Fork Eagle Creek, New Mexico, 2017

About one-quarter of the water supply for the Village of Ruidoso, New Mexico, is derived from groundwater pumping along North Fork Eagle Creek in the Eagle Creek Basin near Alto, New Mexico. Because of concerns regarding the effects of groundwater pumping on surface-water hydrology in the Eagle Creek Basin and the effects of the 2012 Little Bear Fire, which resulted in substantial losses of vegetation in the basin, the monitoring of North Fork Eagle Creek for short-term geomorphic change has been required by the U.S. Department of Agriculture Forest Service, Lincoln National Forest, as part of the permitting decision that allows for the continued pumping of the production wells. The monitoring of short-term geomorphic change in North Fork Eagle Creek began in June 2017 with a geomorphic survey of the stream reach located between the North Fork Eagle Creek near Alto, New Mexico, streamflow-gaging station (USGS site 08387550) and the Eagle Creek below South Fork near Alto, New Mexico, streamflow-gaging station (USGS site 08387600). The 2017 geomorphic survey was conducted by the U.S. Geological Survey (USGS), in cooperation with the Village of Ruidoso, and was the first in a planned series of five annual geomorphic surveys. The results of the 2017 geomorphic survey are summarized and interpreted in this report and are provided in their entirety in its companion data release. The study reach is 1.86 miles long, and large sections of the reach are characterized by intermittent streamflow. Where water is normally present (including at the upper and lower portions of the reach near the streamflow-gaging stations), the discharge typically remains below 2 cubic feet per second throughout the year. Therefore, if geomorphic change is to occur, it will likely be driven by seasonal high-flow events. Discharge records from streamflow-gaging stations in the Eagle Creek Basin indicated that high-flow events in the basin (with peaks above 50 cubic feet per second) typically occurred during the North American monsoon months of July, August, and September. Additionally, the records appear to indicate that, as expected, overland runoff and “flashy” responses to rainfall have increased in the 5 years since the 2012 Little Bear Fire. For the 2017 geomorphic survey of North Fork Eagle Creek, cross sections were established and surveyed at 14 locations along the study reach. Cross-section survey results indicated that channel characteristics (including channel width and area) varied widely along the study reach. Also, as part of the survey, woody debris accumulations and pools in the channel of the study reach were identified, cataloged, photographed, and surveyed for location. There were 58 woody debris accumulations and 14 pools found in the study reach. On the basis that debris jams could be a driver of geomorphic change in North Fork Eagle Creek, woody debris accumulations were classified according to their debris jam potential. The burn marks found on some woody debris indicated that the 2012 Little Bear Fire may be a contributing factor to the volume of debris in North Fork Eagle Creek. However, the woody debris present at the time of the survey did not appear to have substantially affected the geomorphic state of the study reach. Further, the structure and composition of the woody debris accumulations indicated that, under high-flow conditions, most woody debris would likely be transported downstream and out of the study reach without causing substantial geomorphic change through further jamming.

New Mexico↗

USGS1980

Water table in the High Plains aquifer in 1978 in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

The High Plains aquifer includes an area of about 177,000 square miles, with 74 percent of the area in Kansas, Nebraska, and Texas, and 26 percent of the area in Colorado, New Mexico, Oklahoma, South Dakota, and Wyoming. The High Plains aquifer consists of one or more hydraulically connected geologic units of late Tertiary or Quaternary age. The late Tertiary rocks consist of the Brule Formation, Arikaree Group, and Ogallala Formation. The Quaternary rocks consist of alluvial, dune-sand, and valley-fill deposits. The configuration of the water table indicates that the High Plains aquifer is continuous throughout its extent, ground water generally flows west to east, and areas overlain by dune sand are recharge areas. Discharge from the aquifer is primarily to wells and streams. (USGS).

Open-File Report↗

USGS1998

Detailed study of selenium and selected constituents in water, bottom sediment, soil, and biota associated with irrigation drainage in the San Juan River area, New Mexico, 1991-95

In response to increasing concern about the quality of irrigation drainage and its potential effects on fish, wildlife, and human health, the U.S. Department of the Interior began the National Irrigation Water Quality Program (NIWQP) to investigate these concerns at irrigation projects sponsored by the Department. The San Juan River area in northwestern New Mexico was one of the areas designated for study. Study teams composed of scientists from the U.S. Geological Survey, the U.S. Fish and Wildlife Service, the Bureau of Reclamation, and the Bureau of Indian Affairs collected water, bottom-sediment, soil, and biological samples at 61 sites in the San Juan River area during 1993-94. Supplemental data collection conducted during 1991-95 by the Bureau of Indian Affairs and its contractor extended the time period and sampling sites available for analysis. Analytical chemistry performed on samples indicated that most potentially toxic elements other than selenium generally were not high enough to be of concern to fish, wildlife, and human health. Element concentrations in some water, bottom-sediment, soil, and biological samples exceeded applicable standards and criteria suggested by researchers in current literature. Selenium concentrations in water samples from 28 sites in the study area exceeded the 2-microgramper-liter (lg/L) wildlife-habitat standard. Vanadium concentrations in water exceeded the 100-Kg/L standard for livestock-drinking water at one site. In biota, selenium and aluminum concentrations regularly equaled or exceeded avian dietary threshold concentrations. In bottom sediment and soil, element concentrations above the upper limit of the baseline range for western soils were: selenium, 24 exceedances; lead, 2 exceedances; molybdenum, 2 exceedances;strontium, 4 exceedances; and zinc, 4 exceedances. Concentrations of total selenium in bottom-sediment and soil samples were significantly greater for Cretaceous than for non-Cretaceous soil types in the study area and were generally similar for habitats within and outside irrigation-affected areas. Mean and median total-selenium concentrations in samples from areas with Cretaceous soil types were 4.6 and 2.2 micrograms per gram (ps/g), respectively. Mean and median total-selenium concentrations in samples from areas with non-Cretaceous soil types were 0.6 and 0.15 pg/g, respectively. Samples from the study area had low concentrations of organic constituents. Organochlorine pesticides and polychlorinated biphenyls were detected in a few biological samples at low concentrations. Polycyclic aromatic hydrocarbon (PAH) compounds were not detected in whole-water samples collected using conventional water-sampling techniques. In tests involving the use of semipermeable-membrane devices to supplement conventional water assays for PAH's, low concentrations of PAH's were found at several locations in the Hammond Irrigation Supply Canal, but were not detected in the Hammond ponds at the downstream reach of the Hammond irrigation service area. PAH compounds do not appear to reach the San Juan River through the Hammond Canal. Data indicate that water samples from irrigation-drainage-affected habitats had increased mean selenium concentrations compared with samples from irrigation-delivery habitat. The mean selenium concentration in water was greatest at seeps and tributaries draining irrigated land (17 μg/L); less in irrigation drains and in ponds on irrigated land (61.tg/L); and least in backwater, the San Juan River, and irrigation-supply water (0.5 - 0.6 μg/L). Statistical tests imply that irrigation significantly increases selenium concentrations in water samples when a Department of the Interior irrigation project is developed on selenium-rich sediments. Water samples from sites with Cretaceous soils had significantly greater selenium concentrations than water samples from sites with non-Cretaceous soils. Water samples from Department of the Interior project irrigation-drainage sites developed on Cretaceous soils contained a mean selenium concentration about 10 times greater than those in samples from Department of the Interior project sites developed on non-Cretaceous soils. Selenium was much less concentrated in water than in bottom sediment, soil, or biota in the study area. The range in concentrations of dissolved selenium in water was less than 1 ptg/L to 37 1.1g/L (less than 1 to 37 parts per billion). The range in concentrations of total selenium in bottom sediment and soil was less than 0.1 to 23lig/g (less than 100 to 23,000 parts per billion). The range in concentration of selenium in biota was less than 0.1 to 24.0 fig/g (less than 100 to 24,000 parts per billion). Data indicated that bioaccumulation and leaching from soil were the important processes at the study area that lead to elevated levels of selenium. Other processes examined included: (1) evapoconcentration of selenium; (2) atmospheric deposition of aerosols containing selenium; and (3) contamination of surface water by point-source or non-point-source discharges. Selenium concentrations in biological samples were evaluated by a number of variables including: (1) media sampled (emergent and submergent plants, nektonic and benthic invertebrates, omnivore/herbivore and carnivore fish, and terrestrial and aquatic amphibians); (2) habitat (San Juan River main-stem reaches, backwaters, tributary reaches, irrigation delivery or drainage canals, and ponds); (3) irrigation project area and reference sites; and (4) soil type (non-Cretaceous or Cretaceous soils). Graphical techniques and nonparametric statistical tests were applied to determine the influence of selected physiographic variables on selenium concentrations in biological samples collected in the San Juan River area. Species of sucker and of smaller fish contained significantly higher selenium concentrations in the upstream portion of the river where a productive community of plants and animals is found that is associated with warming, nutrient-rich waters discharged from an upstream reservoir. Selenium concentrations in algae, odonates, and mosquitofish collected from both irrigation-drain and pond habitats underlain by Cretaceous soils were significantly greater than in those collected from similar habitats underlain by non-Cretaceous soils. Investigators conclude that the major factor affecting the variability of selenium accumulation in biota at aquatic habitats was the presence of underlying Cretaceous soils. Median selenium concentrations were less than 2 lAg/g for plant samples, less than 7 μg/g for invertebrate samples, and less than 6 lAg/g for whole-fish samples collected from aquatic habitats underlain by non-Cretaceous soils. Similar samples collected from aquatic habitats underlain by Cretaceous soils contained median selenium concentrations two to five times greater. Leaching of selenium from Cretaceous soils in the San Juan River area increases the accumulation of selenium concentrations in the biota and thereby increases the exposure and potential health risks associated with selenium to migratory birds, fish, and other wildlife that use these aquatic habitats extensively. Aquatic habitats presenting the greatest average exposure to excess selenium concentrations in the diets of resident wildlife are from consumption of plants, invertebrates, and fish at irrigation-drain habitats underlain by Cretaceous soils. Of the irrigation projects evaluated in the San Juan River area, the highest median selenium concentrations in algae, cattail leaves, odonate nymphs, mosquitofish, and leopard frog samples from the study area were collected from the east hogback irrigation drain.

New Mexico↗

USGS1942

Reconnaissance survey of the Roberts Mountains, Nevada

The Roberts Mountains region, central Nevada, provides an excellent section of Paleozoic rocks ranging from Upper Cambrian to Permian. Major low-angle thrusting is indicated by deformed Ordovician strata resting on Paleozoics of varying age. Overlying a thick breccia zone, the upper thrust plate consists of sandstones, andesitic flows and tuffs, black shales, and bedded cherts (Vinini formation). Ordovician age of the Vinini is established on the basis of graptolite faunules. A belt of Lower to Middle Ordovician graptolitic facies similar to the Vinini formation crosses the Great Basin west of Roberts Mountains. Deposits of roughly the same age in the Roberts Mountains meridian and eastward are dominantly limestone, carrying distinct faunas. Axial planes of overturned folds in the thrust plate dip west, a further indication that the upper thrust plate moved from west to east. Minimum horizontal displacement is 16 miles. The date of thrusting is uncertain, but presumably was later Cretaceous or early Tertiary. Following thrusting, an alaskite stock and rhyolite porphyry plugs were intruded; lava flows and tuffs covered the area in part. Thrust plate and cover of volcanics have been broken into normal fault blocks. The post-thrusting igneous rocks, like volcanic rocks of Utah and New Mexico, are characterized by high potash content.

Nevada↗

USGS1963

Geology and ground-water resources of Winkler County, Texas

Winkler County, in west Texas, is adjacent to the southeast corner of New Mexico. Most of the county lies in the Pecos Valley; the remainder, in the northeastern part of the county, is part of the Llano Estacado, or the High Plains. Its principal industries are those related to the production and refining of oil, but ranching also is an important occupation. The county has an arid to semiarid climate, an area of about 887 square miles, and a population of about 12,000 in 1957. The principal fresh-water-bearing formations in Winkler County are the Cenozoic alluvium, which mantles the surface of most of the county, and the Santn Rosa sandstone of Late Triassic age. The alluvium is saturated at a depth ranging from a few feet below the land surface to about 150 feet, and the water is under water-table conditions. The Santa Rosa sandstone is fully saturated throughout most of the county, the water occurring under both unconfined (water-table) and confined (artesian) conditions. The underlying older formations contain water too highly mineralized for most uses, but they are important because water from these underlying beds, which is produced with the oil, is a source of pollution to the fresh-water aquifers. The formations also are a source of water to waterflooding projects for the secondary recovery of oil. The alluvium is replenished chiefly by precipitation, throughout the county. The sand-dune area in the eastern part is the most favorable area of natural recharge. The Santa Rosa sandstone is recharged through the alluvium where the two formations are in contact. Infiltration of saline water, which with oil and waste water has been produced from industrial plants, has been taking place through surface earthen pits. About 18 mgd (million gallons per day) of saline water was being produced from the many oil fields throughout the county during August 1957, and almost all this water was placed in surface pits. The Hendrick oil field alone produced about 14.5 mgd during that month, and an estimated 800,000 acre-feet from 1937 to 1957. About 20 million acre-feet of fresh water is stored in the explored groundwater aquifers of Winkler County, of which an estimated 5 to 7 million acrefeet can be practicably recovered. A daily average of about 8.2 million gallons (9,200 acre-feet per year) of fresh water was used in the county during 1956. Public and industrial use accounted for about 6.8 mgd; irrigation, domestic, and stock uses accounted for 1.4 mgd. Projects engaged in the secondary recovery of oil were the largest consumers, using an average of about 3 mgd of fresh water and about 2.7 mgd of saline water during 1956. Water wells drilled in the deep trough of Cenozoic alluvium south of Wink may yield 1,000 gpm (gallons per minute) or more. A pumping test of the alluvium in that area indicated a coefficient of transmissibility of about 25,000 gpd (gallons per day) per foot. Wells, other than windmill wells, drawing water from thinner sections of alluvium in the rest of the county yield between 100 and 300 gpm. Most of the wells in the Santa Rosa sandstone yield 30-400 gpm. Two municipal wells at Kermit that tap the Santa Rosa sandstone were tested at 1,200 and 1,875 gpm. The large yield of these wells probably results from the presence of fractures in the structurally deformed aquifer. Pumping tests in the Kermit area indicate that locally a full section of the Santa Rosa sandstone has an average coefficient of transmissibility of about 25,000 gpd per foot and a coefficient of storage of about 0.0003. The transmissibility in two other tested areas is much less. The chemical quality of the water in the principal aquifers is generally acceptable for industry and for public supply. About two-thirds of the samples collected from fresh-water wells had a dissolved-solids content of less than 1,000 ppm (parts per million) ; however, some samples in a few areas were hard and were high in fluoride and silica. Samples from wells in polluted areas contained dissolved solids ranging from about 1,400 to 71,100 ppm. Two comprehensive analyses of water samples from the Rustler formation showed a dissolved-solids content of 18,400 ppm. and 157,000 ppm. In most of the water produced with the oil in the Hendrick oil field, the content of dissolved solids ranged from about 4,000 to about 10,000 ppm. The water produced with the oil in the rest of the oil fields in Winkler County was mainly brine.

Water Supply Paper↗

USGS2011

Geologic map of the Chisos Mountains, Big Bend National Park, Texas

The Chisos Mountains form some of the highest ground in Texas, second only to Guadalupe Peak near the New Mexico border. The northern half of the range is mostly above 5,500 feet with Emory Peak the high point at 7,825 feet. The mountains are centrally located in Big Bend National Park between Panther Junction and Punta de la Sierra. Big Bend National Park lies near the diffuse border between the Great Plains Province to the northeast and the Sonoran section of the Basin-and-Range structural province to the west and southwest. These geologically unique regions are distinguished from one another by large differences in their landscape and by the amount and style of internal structural deformation. The Great Plains Province is characterized by flat-lying or gently dipping sedimentary strata, low topographic relief, shallow stream valleys, and by a general lack of faulting. Very little active deposition is occurring on the plains, except in the bottoms of active stream valleys. In southwestern Texas the plains stand at average elevations of 2,000 to 3,300 feet and slope gently east toward the Mississippi River and the Gulf of Mexico. The Great Plains have remained relatively unchanged for the last 65 million years, except that they have been uplifted to their present height from lower elevations probably in the last 5 million years. The Basin-and-Range province is characterized by linear parallel mountain ranges, deep sediment-filled valleys, and high structural and topographic relief. The eastern part of the province is at a slightly higher average elevation than the plains. The province is known for its complex patterns of Cenozoic faulting. Today it bears little resemblance to the way it was during the Paleocene when the entire Trans-Pecos region was a simple lowland that was near or slightly below sea level.

Scientific Investigations Map↗

USGS2014

Magnetic susceptibility data for some exposed bedrock in the western conterminous United States

In-place rock magnetic susceptibility measurements for 746 sites in the western conterminous United States are reported in a database. Of these 746 sites, 408 sites are in the Silverton Caldera area of the San Juan Mountains of southwestern Colorado. Of the 408 sites in the Silverton Caldera area, 106 sites are underground. The remaining 338 sites outside the Silverton Caldera area were on outcropping rock, are distributed from southern Arizona to northwestern Wyoming, and include data from California, Nevada, Utah, Colorado, and New Mexico. Rock-density measurements are included for some sites. These data have been collected by various U.S. Geological Survey studies from 1991 through 2012 and are intended to help improve geophysical modeling of the Earth’s crust in the Western United States. A map-based graphical user interface is included to facilitate use of the data.

Arizona, California, Colorado, Nevada, New Mexico,↗

USGS1999

An ARC/Info point coverage of Mineral Resource Data System (MRDS) locations in eleven western states

This ARC/Info coverage, derived from the USGS Mineral Resource Data System (MRDS), contains 60,490 records that fall within the states of Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, Wyoming. The dataset has 13 fields containing information on record identification, location, commodity, geology, and deposit type. The data for this report was retrieved from the master database as a tab text file and imported into a Microsoft Access database. The data was then imported into ESRI’s ArcView where shape files were created. These shape files were then converted into an ARC/INFO coverage.

Arizona, California, Colorado, Idaho, Montana, New↗

USGS2006

Analysis of the Magnitude and Frequency of Peak Discharges for the Navajo Nation in Arizona, Utah, Colorado, and New Mexico

Estimates of the magnitude and frequency of peak discharges are necessary for the reliable flood-hazard mapping in the Navajo Nation in Arizona, Utah, Colorado, and New Mexico. The Bureau of Indian Affairs, U.S. Army Corps of Engineers, and Navajo Nation requested that the U.S. Geological Survey update estimates of peak discharge magnitude for gaging stations in the region and update regional equations for estimation of peak discharge and frequency at ungaged sites. Equations were developed for estimating the magnitude of peak discharges for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years at ungaged sites using data collected through 1999 at 146 gaging stations, an additional 13 years of peak-discharge data since a 1997 investigation, which used gaging-station data through 1986. The equations for estimation of peak discharges at ungaged sites were developed for flood regions 8, 11, high elevation, and 6 and are delineated on the basis of the hydrologic codes from the 1997 investigation. Peak discharges for selected recurrence intervals were determined at gaging stations by fitting observed data to a log-Pearson Type III distribution with adjustments for a low-discharge threshold and a zero skew coefficient. A low-discharge threshold was applied to frequency analysis of 82 of the 146 gaging stations. This application provides an improved fit of the log-Pearson Type III frequency distribution. Use of the low-discharge threshold generally eliminated the peak discharge having a recurrence interval of less than 1.4 years in the probability-density function. Within each region, logarithms of the peak discharges for selected recurrence intervals were related to logarithms of basin and climatic characteristics using stepwise ordinary least-squares regression techniques for exploratory data analysis. Generalized least-squares regression techniques, an improved regression procedure that accounts for time and spatial sampling errors, then was applied to the same data used in the ordinary least-squares regression analyses. The average standard error of prediction for a peak discharge have a recurrence interval of 100-years for region 8 was 53 percent (average) for the 100-year flood. The average standard of prediction, which includes average sampling error and average standard error of regression, ranged from 45 to 83 percent for the 100-year flood. Estimated standard error of prediction for a hybrid method for region 11 was large in the 1997 investigation. No distinction of floods produced from a high-elevation region was presented in the 1997 investigation. Overall, the equations based on generalized least-squares regression techniques are considered to be more reliable than those in the 1997 report because of the increased length of record and improved GIS method. Techniques for transferring flood-frequency relations to ungaged sites on the same stream can be estimated at an ungaged site by a direct application of the regional regression equation or at an ungaged site on a stream that has a gaging station upstream or downstream by using the drainage-area ratio and the drainage-area exponent from the regional regression equation of the respective region.

Scientific Investigations Report↗

USGS2011

Aeromagnetic anomalies over faulted strata

High-resolution aeromagnetic surveys are now an industry standard and they commonly detect anomalies that are attributed to faults within sedimentary basins. However, detailed studies identifying geologic sources of magnetic anomalies in sedimentary environments are rare in the literature. Opportunities to study these sources have come from well-exposed sedimentary basins of the Rio Grande rift in New Mexico and Colorado. High-resolution aeromagnetic data from these areas reveal numerous, curvilinear, low-amplitude (2–15 nT at 100-m terrain clearance) anomalies that consistently correspond to intrasedimentary normal faults (Figure 1). Detailed geophysical and rock-property studies provide evidence for the magnetic sources at several exposures of these faults in the central Rio Grande rift (summarized in Grauch and Hudson, 2007, and Hudson et al., 2008). A key result is that the aeromagnetic anomalies arise from the juxtaposition of magnetically differing strata at the faults as opposed to chemical processes acting at the fault zone. The studies also provide (1) guidelines for understanding and estimating the geophysical parameters controlling aeromagnetic anomalies at faulted strata (Grauch and Hudson), and (2) observations on key geologic factors that are favorable for developing similar sedimentary sources of aeromagnetic anomalies elsewhere (Hudson et al.). High-resolution aeromagnetic surveys are now an industry standard and they commonly detect anomalies that are attributed to faults within sedimentary basins. However, detailed studies identifying geologic sources of magnetic anomalies in sedimentary environments are rare in the literature. Opportunities to study these sources have come from well-exposed sedimentary basins of the Rio Grande rift in New Mexico and Colorado. High-resolution aeromagnetic data from these areas reveal numerous, curvilinear, low-amplitude (2–15 nT at 100-m terrain clearance) anomalies that consistently correspond to intrasedimentary normal faults (Figure 1). Detailed geophysical and rock-property studies provide evidence for the magnetic sources at several exposures of these faults in the central Rio Grande rift (summarized in Grauch and Hudson, 2007, and Hudson et al., 2008). A key result is that the aeromagnetic anomalies arise from the juxtaposition of magnetically differing strata at the faults as opposed to chemical processes acting at the fault zone. The studies also provide (1) guidelines for understanding and estimating the geophysical parameters controlling aeromagnetic anomalies at faulted strata (Grauch and Hudson), and (2) observations on key geologic factors that are favorable for developing similar sedimentary sources of aeromagnetic anomalies elsewhere (Hudson et al.).

The Leading Edge↗

USGS2007

Reported Historic Asbestos Mines, Historic Asbestos Prospects, and Natural Asbestos Occurrences in the Rocky Mountain States of the United States (Colorado, Idaho, Montana, New Mexico, and Wyoming)

This map and its accompanying dataset provide information for 48 natural asbestos occurrences in the Rocky Mountain States of the United States (U.S.), using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos occurrences and their geological characteristics in the Rocky Mountain States. This report is part of an ongoing study by the U.S. Geological Survey to identify and map reported natural asbestos occurrences in the U.S., which thus far includes similar maps and datasets of natural asbestos occurrences within the Eastern U.S. (http://pubs.usgs.gov/of/2005/1189/) and the Central U.S. (http://pubs.usgs.gov/of/2006/1211/). These reports are intended to provide State and local government agencies and other stakeholders with geologic information on natural occurrences of asbestos in the U.S.

Open-File Report↗

USGS2001

New digital magnetic anomaly database for North America

The Geological Survey of Canada (GSC), U.S. Geological Survey (USGS), and Consejo de Recursos Minerales of Mexico (CRM) are compiling an upgraded digital magnetic anomaly database and map for North America. This trinational project is expected to be completed by late 2002.

The Leading Edge↗

USGS2013

Locations and attributes of wind turbines in Colorado, 2011

This dataset represents an update to U.S. Geological Survey Data Series 597. Locations and attributes of wind turbines in Colorado, 2009 (available at http://pubs.usgs.gov/ds/597/). This updated Colorado wind turbine Data Series provides geospatial data for all 1,204 wind turbines established within the State of Colorado as of September 2011, an increase of 297 wind turbines from 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, county, and development status of the wind turbine. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, and year the facility went online. The locations of turbines are derived from 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program (NAIP); the photographs have a positional accuracy of about ±5 meters. Locations of turbines constructed during or prior to August 2009 are based on August 2009 NAIP imagery and turbine locations constructed after August 2009 were based on September 2011 NAIP imagery. The location of turbines under construction during September 2011 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas developed by the U.S. Geological Survey (http://my.usgs.gov/eerma/). The Energy Atlas synthesizes data on existing and potential energy development in Colorado and New Mexico and includes additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools also are included in the Energy Atlas. The format of the Energy Atlas is designed to facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

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