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At least 919 records · Page 51Linked to original sources
USGS2006

Vascular Plant and Vertebrate Inventory of Saguaro National Park, Rincon Mountain District

Executive Summary This report summarizes the results of the first comprehensive inventory of plants and vertebrates at the Rincon Mountain District (RMD) of Saguaro National Park, Arizona. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at the district to document the presence of species within its boundaries. Park staff also surveyed for medium and large mammals using infrared-triggered cameras from 1999 to 2005. This report summarizes the methods and results of these two efforts. Our spatial sampling design was ambitious and was one of the first of its kind in the region to colocate study sites for vegetation and vertebrates using a stratified random design. We also chose the location of some study sites non-randomly in areas that we thought would have the highest species richness. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the district. We also provide an important overview of most previous survey efforts in the district. We use data from our inventory and other surveys to compile species lists and to assess inventory completeness. With the exception of plants, our survey effort was the most comprehensive ever undertaken in the district. We recorded a total of 801 plant and vertebrate species, including 50 species not previously found in the district (Table 1) of which five (all plants) are non-native species. Based on a review of our inventory and past research at the district, there have been a total of 1,479 species of plants and vertebrates found there. We believe inventories for all taxonomic groups are nearly complete. In particular, the plant, amphibian and reptile, and mammal species lists are the most complete of any comparably large natural area of the 'sky island' region of southern Arizona and adjacent Mexico. For each taxon-specific chapter we discuss patterns of species richness and environmental determinants of these patterns. For all groups except medium and large mammals, the low elevation stratum (<4,000 feet) contained the highest species richness, after accounting for differences in survey effort among strata. This is consistent with known patterns of species richness in the sky island mountain ranges. Using data on relative abundance for plants and birds, we were able to identify a number of distinct ecological communities, which were consistent with known patterns in the sky islands. Our review of species lists and park records reveals that the district has lost species, particularly plants and mammals, in the past few decades. Because of the district's close proximity to the rapidly growing city of Tucson, there are a number of development-related threats that could cause additional species loss or decline in abundance of some species. In particular, the increasing groundwater pumping near Rincon Creek, the most species-rich area in the park, is likely to impact the unique riparian vegetation and animals of that area. We discuss this and other demands on the ecological integrity of the district. We also recommend additional inventory, monitoring, and research studies.

Open-File Report↗
USGS2006

Preliminary surficial geologic map of a Calico Mountains piedmont and part of Coyote Lake, Mojave desert, San Bernardino County, California

This 1:24,000 scale detailed surficial geologic map and digital database of a Calico Mountains piedmont and part of Coyote Lake in south-central California depicts surficial deposits and generalized bedrock units. The mapping is part of a USGS project to investigate the spatial distribution of deposits linked to changes in climate, to provide framework geology for land use management (http://deserts.wr.usgs.gov), to understand the Quaternary tectonic history of the Mojave Desert, and to provide additional information on the history of Lake Manix, of which Coyote Lake is a sub-basin. Mapping is displayed on parts of four USGS 7.5 minute series topographic maps. The map area lies in the central Mojave Desert of California, northeast of Barstow, Calif. and south of Fort Irwin, Calif. and covers 258 sq.km. (99.5 sq.mi.). Geologic deposits in the area consist of Paleozoic metamorphic rocks, Mesozoic plutonic rocks, Miocene volcanic rocks, Pliocene-Pleistocene basin fill, and Quaternary surficial deposits. McCulloh (1960, 1965) conducted bedrock mapping and a generalized version of his maps are compiled into this map. McCulloh's maps contain many bedrock structures within the Calico Mountains that are not shown on the present map. This study resulted in several new findings, including the discovery of previously unrecognized faults, one of which is the Tin Can Alley fault. The north-striking Tin Can Alley fault is part of the Paradise fault zone (Miller and others, 2005), a potentially important feature for studying neo-tectonic strain in the Mojave Desert. Additionally, many Anodonta shells were collected in Coyote Lake lacustrine sediments for radiocarbon dating. Preliminary results support some of Meek's (1999) conclusions on the timing of Mojave River inflow into the Coyote Basin. The database includes information on geologic deposits, samples, and geochronology. The database is distributed in three parts: spatial map-based data, documentation, and printable map graphics of the database. Spatial data are distributed as an ArcInfo personal geodatabase, or as tabular data in the form of Microsoft Access Database (MDB) or dBase Format (DBF) file formats. Documentation includes this file, which provides a discussion of the surficial geology and describes the format and content of the map data, and Federal Geographic Data Committee (FGDC) metadata for the spatial map information. Map graphics files are distributed as Postscript and Adobe Acrobat Portable Document Format (PDF) files, and are appropriate for representing a view of the spatial database at the mapped scale.

Open-File Report↗
USGS2006

Aeromagnetic and gravity data over the Central Transantarctic Mountains (CTAM), Antarctica: a website for the distribution of data and maps

Near complete coverage of the East Antarctic Shield by ice hampers geological study of crustal architecture important for understanding global tectonic and climate history. Limited exposures in the central Transantarctic Mountains (CTAM), however, show that Archean and Proterozoic rocks of the shield as well as Neoproterozoic-lower Paleozoic sedimentary successions were involved in oblique convergence associated with Gondwana amalgamation. Subsequently, the area was overprinted by Jurassic magmatism and Cenozoic uplift. To extend the known geology of the region to ice-covered areas, we conducted an aeromagnetic survey flown in draped mode by helicopters over the Central Transantarctic Mountains and by fixed-wing aircraft over the adjacent polar plateau. We flew more than 32,000 line km covering an area of nearly 60,000 km2 at an average altitude of 600 m, with average line spacing 2.5 km over most areas and 1.25 km over basement rocks exposed in the Miller and Geologists ranges. Additional lines flown to the north, south, and west extended preliminary coverage and tied with existing surveys. Gravity data was collected on the ground along a central transect of the helicopter survey area.

Open-File Report↗
USGS2006

Report of the workshop on Extreme Ground Motions at Yucca Mountain, August 23-25, 2004

This Workshop has its origins in the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain, the designated site of the underground repository for the nation's high-level radioactive waste. In 1998 the Nuclear Regulatory Commission's Senior Seismic Hazard Analysis Committee (SSHAC) developed guidelines for PSHA which were published as NUREG/CR-6372, 'Recommendations for probabilistic seismic hazard analysis: guidance on uncertainty and the use of experts,' (SSHAC, 1997). This Level-4 study was the most complicated and complex PSHA ever undertaken at the time. The procedures, methods, and results of this PSHA are described in Stepp et al. (2001), mostly in the context of a probability of exceedance (hazard) of 10-4/yr for ground motion at Site A, a hypothetical, reference rock outcrop site at the elevation of the proposed emplacement drifts within the mountain. Analysis and inclusion of both aleatory and epistemic uncertainty were significant and time-consuming aspects of the study, which took place over three years and involved several dozen scientists, engineers, and analysts.

Open-File Report↗
USGS2007

Rocky Mountain Snowpack Chemistry at Selected Sites, 2004

During spring 2004, the U.S. Geological Survey in cooperation with the National Park Service and the U.S. Department of Agriculture, Forest Service collected and analyzed snowpack samples for 65 sites in the Rocky Mountain region from New Mexico to Montana. Snowpacks were sampled from late February through early April and generally had well-below-average- to near-average snow-water equivalent. Regionally, on April 1, snow-water equivalent ranged from 50 to 89 percent. At most regional sites monitored during 1993-2004, snowpack ammonium, nitrate, and sulfate concentrations for 2004 were lower than the 12-year averages. Snowpack ammonium concentrations in the region were lower than average concentrations for the period at 61 percent of sites in the region, but showed a new pattern compared to previous years with three of the four highest 2004 concentrations observed in northern Colorado. Nitrate concentrations in 2004 were lower than the 12-year average for the year at 53 percent of regional sites, and typically occurred at sites in Wyoming, Idaho, and Montana where powerplants and large industrial areas were limited. A regional decrease in sulfate concentrations across most of the Rocky Mountains (with concentrations lower than the 12-year average at 84 percent of snowpack sites) was consistent with other monitoring of atmospheric deposition in the Western United States. Total mercury concentrations, although data are only available for the past 3 years, decreased slightly for the region as a whole in 2004 relative to 2003. Ratios of stable sulfur isotopes indicated a similar regional pattern as observed in recent years with sulfur-34 (d34S) values generally increasing northward from northern New Mexico and southern Colorado to northern Colorado, Wyoming, Idaho, and Montana.

Open-File Report↗
USGS2007

Geologic Mapping and Mineral Resource Assessment of the Healy and Talkeetna Mountains Quadrangles, Alaska Using Minimal Cloud- and Snow-Cover ASTER Data

On July 8, 2003, ASTER acquired satellite imagery of a 60 km-wide swath of parts of two 1:250,000 Alaska quadrangles, under favorable conditions of minimal cloud- and snow-cover. Rocks from eight different lithotectonic terranes are exposed within the swath of data, several of which define permissive tracts for various mineral deposit types such as: volcanic-hosted massive sulfides (VMS) and porphyry copper and molybdenum. Representative rock samples collected from 13 different lithologic units from the Bonnifield mining district within the Yukon-Tanana terrane (YTT), plus hydrothermally altered VMS material from the Red Mountain prospect, were analyzed to produce a spectral library spanning the VNIR-SWIR (0.4 - 2.5 ?m) through the TIR (8.1 - 11.7 ?m). Comparison of the five-band ASTER TIR emissivity and decorrelation stretch data to available geologic maps indicates that rocks from the YTT display the greatest range and diversity of silica composition of the mapped terranes, ranging from mafic rocks to silicic quartzites. The nine-band ASTER VNIR-SWIR reflectance data and spectral matched-filter processing were used to map several lithologic sequences characterized by distinct suites of minerals that exhibit diagnostic spectral features (e.g. chlorite, epidote, amphibole and other ferrous-iron bearing minerals); other sequences were distinguished by their weathering characteristics and associated hydroxyl- and ferric-iron minerals, such as illite, smectite, and hematite. Smectite, kaolinite, opaline silica, jarosite and/or other ferric iron minerals defined narrow (< 250 m diameter) zonal patterns around Red Mountain and other potential VMS targets. Using ASTER we identified some of the known mineral deposits in the region, as well as mineralogically similar targets that may represent potential undiscovered deposits. Some known deposits were not identified and may have been obscured by vegetation- or snow-cover, or were too small to be resolved.

Open-File Report↗
USGS2007

The Ellsworth Mountains: critical and enduringly enigmatic

The Ellsworth Mountains, first mapped under the leadership of Campbell Craddock, pose critical geological enigmas, solved and unsolved. The isolation of the mountains, their abrupt structural terminations and Paleozoic stratigraphic affinities are explained by rotation from the cratonic margin during Gondwanaland breakup. The mechanism remains obscure. The absence of intense folding associated with the Cambro-Ordovician Ross orogeny can be ascribed to local extension along a subducting margin. Yet tantalizing questions regarding possible Precambrian connections to Laurentia remain, and the cause of the post-Permian Gondwanide folding is controversial. The elevation (~5000m) is high for an early Mesozoic fold belt. Thermal uplift could have been initiated during Jurassic-Cretaceous block rotation and Weddell Sea opening and continued into the Cenozoic. The history of glaciation provides input for models of ice loading and unloading. Measurements of present-day uplift test these models and help assess change in the mass of the ice sheet and hence in global sea level.

Open-File Report↗
USGS2007

Lithospheric structure across the Transantarctic Mountains constrained by an analysis of gravity and thermal structure

The Transantarctic Mountains demarcate the boundary between the highly extended lithosphere of the West Antarctic Rift System and the Proterozoic East Antarctic Craton. Although the last stage of relief development was in the Eocene, the TAM retain peak elevations in excess of 4500 m. This combination of old age and high relief are difficult to reconcile, and the mechanism(s) responsible for uplift and support of this mountain range remain elusive and controversial. Recent seismic studies provide key constraints on the crustal structure. Here we constrain the lithospheric structure across this boundary by forward modeling of the gravity based on a density structure that reflects the thermal structure. Our results show that the observed very-long wavelength (>500km) gravity anomaly can be modeled by a West Antarctic lithosphere ~60 km thick, and an East Antarctic lithosphere ~250 km thick. In addition, the gravity anomaly associated with the TAM can be modeled by including the thermal effects of heat producing elements concentrated in the crust.

Open-File Report↗
USGS2007

Major, trace element and stable isotope geochemistry of synorogenic breccia bodies, Ellsworth Mountains, Antarctica

Cambrian carbonates in the Heritage Range of the Ellsworth Mountains, West Antarctica host a series of carbonate-rich breccia bodies that formed contemporaneously with the Permian Gondwanide orogen. The breccia bodies had a three-stage genesis, with the older breccias containing Cambrian limestone (and marble) clasts supported by calcite, whereas the younger breccias are nearly clast-free and composed entirely of matrix calcite. Breccia clasts, calcite matrix and detrital matrix samples were analyzed using x-ray fluorescence (major and trace elements), x-ray diffraction, and stable isotopes (C, O) and suggest that the breccias formed as part of a closed geochemical system, at considerable depth, within the Cambrian limestone host as the Ellsworth Mountains deformed into a fold-and-thrust belt along the margin of Gondwana

Open-File Report↗
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↗
USGS2007

Science Review for the Scott Bar Salamander (Plethodon asupak) and the Siskiyou Mountains Salamander (P. stormi): Biology, Taxonomy, Habitat, and Detection Probabilities/Occupancy

The Plethodon elongatus Complex in the Klamath-Siskiyou Ecoregion of southern Oregon and northern California includes three species: the Del Norte salamander, Plethodon elongatus; the Siskiyou Mountains salamander, P. stormi; and the Scott Bar salamander, P. asupak. This review aims to summarize the current literature and information available on select topics for P. stormi and P. asupak. These are both terrestrial salamanders belonging to the Family Plethodontidae, which contains more species and has a wider geographic distribution than any other family of salamanders (Wake 1966, 2006; Pough 1989). The genera of this family have greatly diversified ecologically across North America, Central America, northern South America, Sardinia, southeastern France and northwestern Italy, and have recently been discovered on the Korean peninsula (Min et al. 2005). The genus Plethodon is found exclusively in North America and is split into three distinct clades, based upon morphology and phylogenetics (Highton and Larson 1979): eastern small Plethodon, eastern large Plethodon, and the western Plethodon. The western Plethodon are the greatest representation of Plethodontidae in the Pacific Northwest, with 8 species. The two species with the most restricted ranges of these regional congeners are the Siskiyou Mountains and Scott Bar salamanders. These salamanders occupy the interior of the Klamath-Siskiyou Ecoregion which straddles the California and Oregon state lines, between Siskiyou County (CA) and Jackson and Josephine Counties (OR). The relatively recent discovery of P. asupak (Mead et al. 2005) and the limited range of both species have created an environment of uncertain conservation status for these species. This review will focus on four central topics of concern for land and resource managers: Biology; Taxonomy; Habitat; and Detection Probabilities/Occupancy.

Open-File Report↗
USGS2008

Preliminary Geologic Map of the Culebra Peak Area, Sangre de Cristo Mountains, Las Animas and Costilla Counties, Colorado

This geologic map provides new geologic mapping at 1:50,000-scale in the Culebra Peak area of the Sangre de Cristo Mountains of south-central Colorado. The map area includes all of the El Valle Creek, Stonewall, Culebra Peak, and Torres 7.5' quadrangles. Paleoproterozoic crystalline basement rocks are exposed along the crest of the Culebra Range which include a calc-alkaline gneiss sequence and a metasedimentary and bimodal metavolcanic sequence which are strongly foliated and display a northeast-southwest oriented structural trend. These rocks are intruded by several large granitic bodies and smaller amphibolitic and pegmatitic bodies which are also foliated. These basement rocks are intruded by a set of younger Neoproterozoic to lower Paleozoic gabbro dikes which are nonfoliated. These crystalline rocks are overlain to the east of the Culebra Range by a thick sequence of Phanerozoic sedimentary rocks which include upper Paleozoic syn-tectonic sedimentary rocks of the Colorado Trough related to the Ancestral Rocky Mountains, Mesozoic post-tectonic sedimentary rocks, Cretaceous interior seaway sediments, and Laramide-age syn-tectonic sedimentary rocks of the Raton Basin. These rocks are faulted and folded by Laramide-age deformation. Tertiary igneous and volcaniclastic rocks that postdate the Laramide Orogeny are exposed throughout the map area and to the west of the Culebra Range, syntectonic sedimentary and volcanic rocks of the Sante Fe Group were deposited as fill in basins of the Rio Grande rift. These deposits are cut by rift-related extensional faults. Surficial units include alluvial, lacustrine, glacial, and mass-wasting deposits.

Open-File Report↗
USGS2009

Complete Analytical Data for Samples of Jurassic Igneous Rocks in the Bald Mountain Mining District, Nevada

This report presents all petrographic, major oxide, and trace element data for a set of 109 samples collected during an investigation of Jurassic igneous rocks in the Bald Mountain mining district, Nevada. Igneous rocks in the district include the Bald Mountain stock, quartz-feldspar porphyry dikes, basaltic andesite dikes, aplite sills, and rare lamprophyre dikes. These rocks, although variably altered near intrusion-related mineral deposits, are fresh in many parts of the district. Igneous rocks in the district are hosted by Paleozoic sedimentary rocks.

Open-File Report↗
USGS2009

Final Report for Emergency Stabilization and Rehabilitation Treatment Monitoring of the Keeney Pass, Cow Hollow, Double Mountain, and Farewell Bend Fires

A strategy for monitoring post-fire seedings in the sagebrush steppe of the Intermountain West was developed and used to monitor four example fires in the Vale, Oregon District of the Bureau of Land Management (BLM). We began to develop a potential approach by (1) reviewing previous vegetation monitoring manuals produced by the Federal government to determine what techniques and approaches had been approved for use, and (2) monitoring a set of example fire rehabilitation projects from 2006 through 2008. We reviewed seven vegetation monitoring manuals approved for use by the Federal government. From these seven manuals, we derived a set of design elements appropriate for monitoring post-fire rehabilitation and stabilization projects. These design elements consisted of objectives, stratification, control plots, random sampling, data quality, and statistical analysis. Additionally, we chose three quantitative vegetation field procedures that were objective and repeatable to be used in conjunction with these six design elements. During the spring and summer of 2006 to 2008, U.S. Geological Survey personnel monitored vegetation in seven post-fire seeding treatments in four burned areas in the Vale district of the BLM in eastern Oregon. Treatments monitored included a native and non-native seeding in each of the Farewell Bend, Double Mountain, and Keeney Pass fires, and a native seeding at the Cow Hollow fire. All fires occurred in 2005. There generally was a low level of plant establishment for all seedings by 2008. The quantitative objective established by the BLM was to achieve 5 seeded grass plants/m2 by the end of 3 years as a result of the seeding. There was an estimated 3.97 and 6.28 plants/m2 in 2006 and 1.06 and 0.85 plants/m2 seeded perennial grasses in 2008 from the Keeney Pass non-native and native seeding, respectively. The Cow Hollow seeding resulted in the lowest establishment of perennial seeded grasses of the four project areas with 0.69 plants/m2 in 2006 and 0.09 plants/m2 in 2008. Density of seeded perennial grasses at the Double Mountain non-native and native seeding were 2.72 and 3.86 plants/m2 in 2006 and 0.90 and 1.74 plants/m2 in 2008, respectively. The Farewell Bend non-native seeding resulted in 5.62 plants/m2 in 2006 and 0.42 plants/m2 in 2008 while the native seeding had 2.22 seeded grass plants/m2 in 2006 and 0.44 plants/m2 by 2008. The primary reason for low level of establishment on most treatments except the Cow Hollow seeding was most likely the unfavorable timing and amount of precipitation in 2007 and 2008. Measurements of density within the first 3 years provide the best estimate of initial seeding success. Increases in cover due to the seedings were not detectable in the first 3 years following seeding in this monitoring effort. Changes in cover resulting from the treatments may be detectable in cases where the seedings were very successful in the first 3 years following seeding, but in areas with lower annual average precipitation, may not occur consistently. As a result, cover of seeded species may not be a good indication of seeding success in the early years after treatment. However, cover is useful for monitoring initial patterns of abundance of naturally recovering vegetation, exotic annual grasses and forbs, and bare ground. Cover measurements at these four sites revealed patterns common to most of the treatment areas in cover of litter, bare ground, and exotic annuals in response to drill seeding and weather patterns. There was a rapid increase in litter at all treatments after the fire. Additionally, there was less litter in treatment plots than in the control plots in 2006 probably due to the mechanical action of the seed drill. There also was a corresponding decrease in bare ground from 2006 to 2008. Initially, higher bare ground cover at treatment plots appears to be due to the mechanical action of the seed drill. Cover of annual grasses, primarily Bromus tectorum,

Open-File Report↗
USGS2010

Relations Between Rainfall and Postfire Debris-Flow and Flood Magnitudes for Emergency-Response Planning, San Gabriel Mountains, Southern California

Following wildfires, emergency-response and public-safety agencies are faced often with making evacuation decisions and deploying resources both well in advance of each coming winter storm and during storms themselves. Information critical to this process is provided for recently burned areas in the San Gabriel Mountains of southern California. The National Weather Service (NWS) issues Quantitative Precipitation Forecasts (QPFs) for the San Gabriel Mountains twice a day, at approximately 4 a.m. and 4 p.m., along with unscheduled updates when conditions change. QPFs provide estimates of rainfall totals in 3-hour increments for the first 12-hour period and in 6-hour increments for the second 12-hour period. Estimates of one-hour rainfall intensities can be provided in the forecast narrative, along with probable peak intensities and timing, although with less confidence than rainfall totals. A compilation of information on the hydrologic response to winter storms from recently burned areas in southern California steeplands was used to develop a system for classifying the magnitude of the postfire hydrologic response. The four-class system is based on a combination of the reported volume of individual debris flows, the consequences of these events in an urban setting, and the spatial extent of the response to the triggering storm. Threshold rainfall conditions associated with debris flow and floods of different magnitude classes are defined by integrating local rainfall data with debris-flow and flood magnitude information. The within-storm rainfall accumulations (A) and durations (D) above which magnitude I events are expected are defined by A=0.3D0.6. The function A=0.5D0.6 defines the within-storm rainfall accumulations and durations above which a magnitude III event will occur in response to a regional-scale storm, and a magnitude II event will occur if the storm affects only a few drainage basins. The function A=1.0D0.5defines the rainfall conditions above which magnitude III events can be expected. Rainfall trigger-magnitude relations are linked with potential emergency-response actions in the form of an emergency-response decision chart. The chart leads a user through steps to determine potential event magnitudes, and identify possible evacuation and resource-deployment levels as a function of either individual storm forecasts or measured precipitation during storms. The ability to use this information in the planning and response decision-making process may result in significant financial savings and increased safety for both the public and emergency responders.

Open-File Report↗
USGS2011

Aqueous geochemical data from the analysis of stream-water samples collected in June and July 2006 — Taylor Mountains 1:250,000-scale quadrangle, Alaska

We report on the chemical analysis of water samples collected from the Taylor Mountains 1:250,000-scale quadrangle, Alaska. Parameters for which data are reported include pH, conductivity, water temperature, major cation and anion concentrations, trace-element concentrations, and dissolved organic-carbon concentrations. Samples were collected as part of a multiyear U.S. Geological Survey project entitled ?Geologic and Mineral Deposit Data for Alaskan Economic Development.? Data presented here are from samples collected in June and July 2006. The data are being released at this time with minimal interpretation. This is the third release of aqueous geochemical data from this project; aqueous geochemical data from samples collected in 2004 and 2005 were published previously. The data in this report augment but do not duplicate or supersede the previous data release. Site selection was based on a regional sampling strategy that focused on first- and second-order drainages. Water sample site selection was based on landscape parameters that included physiography, wetland extent, lithological changes, and a cursory field review of mineralogy from pan concentrates. Stream water in the Taylor Mountains quadrangle is dominated by bicarbonate (HCO3-), although in a few samples more than 50 percent of the anionic charge can be attributed to sulfate (SO42-). The major-cation chemistry ranges from Ca2+/Mg2+ dominated to a mix of Ca2+/Mg2+/Na++K+. Generally, good agreement was found between the major cations and anions in the duplicate samples. Many trace elements in these samples were at or near the analytical method detection limit, but good agreement was found between duplicate samples for elements with detectable concentrations. All field blank major-ion and trace-element concentrations were below detection.

Alaska↗
USGS2011

Monitoring plan for vegetation responses to elk management in Rocky Mountain National Park

Rocky Mountain National Park (RMNP) in north-central Colorado supports numerous species of wildlife, including several large ungulate species among which Rocky Mountain elk (Cervus elaphus) are the most abundant. Elk are native to RMNP but were extirpated from the area by the late 1800s. They were reintroduced to the area in 1913-1914, and the elk herd grew to the point that it was actively managed from 1944 until 1968. In 1969, the active control of elk was discontinued and since then the herd has increased to a high point ranging from 2,800 to 3,500 between 1997 and 2001. In recent years, there has been growing concern over the condition of vegetation in the park and conflicts between elk and humans, both inside and outside the park. In response to these concerns, RMNP implemented an Elk and Vegetation Management Plan (EVMP) in 2009 to guide management actions in the park over a 20-year time period with the goal of reducing the impacts of elk on vegetation and restoring the natural range of variability in the elk population and affected plant and animal communities. The EVMP outlines the desired future condition for three vegetation communities where the majority of elk herbivory impacts are being observed: aspen, montane riparian willow, and upland herbaceous communities. The EVMP incorporates the principle of adaptive management whereby the effectiveness of management actions is assessed and adjusted as needed to successfully achieve objectives. Determination of whether vegetation objectives are being achieved requires monitoring and evaluation of target vegetation communities. The current report describes the design and implementation of a vegetation-monitoring program to help RMNP managers assess the effectiveness of their management actions and determine when and where to alter actions to achieve the EVMP's vegetation objectives. This monitoring plan details the process of selecting variables to be monitored, overall sampling design and structure, site selection, data collection methods, and statistical analyses to be used to conduct this monitoring program in conjunction with the EVMP. We report the baseline conditions observed at the time of the establishment of monitoring sites. We include detailed field protocols for site establishment and data collection, as well as timetables for sampling, so that RMNP staff will be able to continue monitoring the sites established during this implementation stage, and continue to add new sites when necessary, as the execution of the EVMP proceeds over the next 20 years.

Colorado↗
USGS2011

40 Ar/ 39 Ar age-spectrum data for hornblende, biotite, white mica, and K-feldspar samples from metamorphic rocks in the Great Smoky Mountains of North Carolina and Tennessee

This report contains reduced 40 Ar/ 39 Ar data of hornblende, biotite, white mica and (or) sericite, and potassium-feldspar mineral separates and phyllite groundmass samples from metamorphic rocks of the Great Smoky Mountains in North Carolina and Tennessee. Included in this report are information on the location of the samples and a brief description of the samples. The data contained herein are not interpreted in a geological context, and care should be taken by users unfamiliar with argon isotopic data in the use of these results. No geological meaning is implied for any of the apparent ages presented below, and many of the individual apparent ages are not geologically meaningful. This report is primarily a detailed source document for subsequent publications that will integrate these data into a geological context. All the samples in this report were collected in and around the Great Smoky Mountain National Park in western North Carolina and eastern Tennessee.

North Carolina, Tennessee↗