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USGS2011

The United Nations framework classification for fossil energy and mineral reserves and resources 2009

Effective resource management in a globalizing economy requires accurate assessments of fossil energy and minerals resources. The recoverable quantities must be described and categorized in a manner that is consistent with scientific and social/economic information describing the economy as well as with the information describing the projects to recover them. A number of different standards have evolved over time in response to various professional needs Under a mandate given by the United Nations Economic and Social Council, the United Nations Economic Commission for Europe (UNECE) has cooperated with Governments, regulatory agencies, industry, international organizations, and professional organizations (including Committee for Mineral Reserves International Reporting Standards (CRIRSCO), the Society of Petroleum Engineers (SPE), the American Association of Petroleum Geologists (AAPG), and the Society of Petroleum Evaluation Engineers (SPEE)), as well as with outstanding experts, to define a global classification for extractive activities (including oil, gas, heavy oil and bitumen extraction) that reflects the principal concerns of existing petroleum and mineral classifications. The United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources-2009 (UNFC-2009) aims to serve the following four principal needs: 1. The needs in international energy and mineral studies to formulate robust and long-sighted policies. 2. The needs of governments in managing their resources accordingly, allowing market prices to be transferred to the wellhead with as little loss as possible. 3. The industries' needs for information while deploying technology, management and finance to secure energy supplies and capture value efficiently within the established frameworks to serve its host countries, shareholders and stakeholders. 4. The financial community's need for information to allocate capital appropriately, providing reduced costs and improved long-sightedness through the application of lower risk-compensated discount factors. The projects are categorised with respect to economic and social viability, project feasibility and maturity and uncertainty with respect to the quantities addressed. The categorisation of projects rather than of accumulations provides coherence with other critical management information such as production, cash flows, value and demand for various input factors. This key aspect of UNFC-2009 reflects the critical relationship between the quantities that can be recovered economically and the recovery processes (projects) that must be implemented to achieve those recoveries. It facilitates the recognition of potential wastage of resources through flaring or inefficient recovery processes and therefore also the potential for improvement. Copyright 2011, Society of Petroleum Engineers.

Conference Paper↗
USGS1905

Economic geology of the Bingham mining district, Utah

The field work of which this report represents the final results was first undertaken in the summer of the year 1900. This district had long been selected by the writer as worthy of special economic investigation, as well on account of the importance of its products as because of its geological structure and the peculiar relations of its ore deposits. It was not, however, until the summer mentioned above that the means at the disposal of the Survey, both pecuniary and scientific, justified its undertaking. As originally planned, the areal or surface geology was to have been worked out by Mr. Keith, who had already spent many years in unraveling the complicated geological structure of the Appalachian province, while Mr. Boutwell, who had more recently become attached to the Survey, was to have charge of the underground geology, or a study of the ore deposits, under the immediate supervision of the writer. When the time came for actually taking the field, it was found that the pressure of other work would not permit Mr. Keith to carry out fully the part allotted to him, and in consequence a part of his field work has fallen to Mr. Boutwell. Field work was commenced by the writer and Mr. Boutwell early in July, 1900. Mr. Keith joined the party on August 10, but was obliged to leave for other duties early in September. Mr. Boutwell carried on his field work continuously from July until December, taking up underground work after the snowfall had rendered work on the surface geology impracticable. The geological structure had proved to be unexpectedly intricate and complicated, so that, on the opening of the field season of 1901, it was found necessary to make further study in the light of results already worked out, and Mr. Boutwell spent some weeks in the district in the early summer of 1901. His field work that year, partly in California and partly in Arizona, as assistant to Mr. Waldemar Lindgren, lasted through the summer and winter and well into the spring of 1902, so that but little time , was left before he was obliged to take the field again in his study of the Park City district of Utah. Mr. Keith had been too closely occupied with his Appalachian work to complete his part,' and thus the publication of this report has been unusually delayed. While the delay is a cause for regret, this regret is much tempered by the consideration that had the report been published earlier many facts brought to light during the vigorous development of the region in late years, which have an important bearing upon the structure and genesis of the ore deposits, could not have been used in its preparation.

Utah↗
USGS2015

Groundwater flow in the Brunswick/Glynn County area, Georgia, 2000-04

An existing regional steady-state model for coastal Georgia, and parts of South Carolina and Florida, was revised to evaluate the local effects of pumping on the migration of high chloride (saline) water in the Upper Floridan aquifer located in the Brunswick/Glynn County, Georgia (Ga.) area. Revisions were focused on enhancing the horizontal and vertical resolution of the regional model grid in the vicinity of saline water. Modifications to the regional model consisted of (1) limiting grid size to a maximum of 500 feet (ft) per side in the vicinity of chloride contamination; (2) representing the upper and lower Brunswick aquifers with distinct model layers; (3) similarly, representing upper and lower water-bearing zones of the Upper Floridan aquifer with distinct model layers in Glynn and Camden Counties, Ga.; and (4) establishing new hydraulic-property zones in the Upper Floridan aquifer. The revised model simulated steady-state conditions that were assumed to exist during 2000 and 2004. Calibration of the revised steady-state model using pumping rates from 2000 indicates a "good" match (±10 ft) based on 181 observations, with median residuals (simulated minus observed water levels) in each of the active model layers ranging from -8.62 to 4.67 ft, and root mean square error (RMSE) ranging from 10.9 to 11.4 ft. In the Brunswick/Glynn County area, groundwater-level residuals in the upper water-bearing zone of the Upper Floridan aquifer (layer 7) indicate an "excellent" match (±5 ft) based on 41 observations with a median residual of -0.35 ft and RMSE of 4.32 ft. Calibration of the revised steady-state model using 2004 pumping rates and adjusted specified-head input values in the Floridan aquifer system indicates a "good" match (-10 ft) based on 88 observations, with median residuals in each of the active model layers ranging from -6.31 to -2.05 ft, and RMSE ranging from -6.95 to 14.5 ft. In the Brunswick/Glynn County area, groundwater-level residuals in the upper water-bearing zone of the Upper Floridan aquifer (layer 7) indicate an "excellent" match (±5 ft) based on 32 observations with a median residual of -1.50 ft and RMSE of 5.34 ft. Simulated potentiometric surfaces for 2000 and 2004 indicate coastward groundwater flow in the Upper and Lower Floridan aquifers influenced by pumping centers at Savannah, Jesup, and Brunswick, Ga., and indicate steep potentiometric gradients to the west and north of the Gulf Trough. In the Brunswick/Glynn County area, simulated industrial production wells located north of downtown Brunswick intercept local groundwater flow in the upper and lower water-bearing zones of the Upper Floridan aquifer and have created a cone of depression that locally alters the regional coastward flow direction. Maps of simulated water-level change during the 2000-04 period show differences in groundwater levels in the Upper Floridan aquifer that range from -2.5 ft to more than 5 ft in areas of coastal Georgia, and more than 20 ft near the Georgia-Florida State Line. Positive values indicate higher simulated water levels during 2004 than during 2000, which were caused by reduced pumping in the Upper Floridan aquifer prompted by the shutdown of a paper mill near the southern model boundary in 2002 and increased recharge following a prolonged drought during 1998-2002. Simulated potentiometric profiles for 2000 and 2004 were used to evaluate the potentiometric gradients in the upper water-bearing zone of the Upper Floridan aquifer (layer 7) near the chloride plume in the downtown Brunswick area. Four potentiometric profiles were constructed for 2000 to compare the simulated and observed water levels in 13 wells and were oriented outward from a primary well field. The simulated potentiometric gradients from the four profiles for 2000 ranged from 3.6 to 5.2 feet per mile (ft/mi) compared to observed values ranging from 4.1 to 5.6 ft/mi. The five potentiometric profiles constructed for 2004 allowed for a similar comparison using simulated and observed water levels in 18 wells. The simulated potentiometric gradients from the five profiles for 2000 ranged from 3.6 to 11.1 ft/mi compared to observed values ranging from 3.8 to 10.2 ft/mi. Simulated potentiometric gradients were higher for 2004 than for 2000 because of the inclusion of a well located within the cone of depression near downtown Brunswick. Composite-scaled sensitivities of the model parameters indicate the revised model is most sensitive to pumping rates, followed by the horizontal hydraulic conductivity in the Upper Floridan aquifer for zones along coastal Georgia. The revised model is least sensitive to the horizontal hydraulic conductivity of the confining units and vertical hydraulic conductivity of the aquifers. For parameters defined by hydraulic-property zones in the upper and lower water-bearing zones of the Upper Floridan aquifer, such as horizontal hydraulic conductivity, model sensitivity was not as great in the Brunswick/Glynn County area as other areas along coastal Georgia. The model exhibited more sensitivity to these parameters however, than to parameters representing the majority of zones defining the vertical hydraulic conductivity of the confining units, which originally were assumed to govern upward migration of chloride contamination into this aquifer. Analysis of simulated water-budget components for 2000 and 2004 indicate that specified-head boundaries in the Floridan aquifer system to the south and southwest of the regional model area control about 70 percent of inflows and nearly 50 percent of outflows to the model region. Other water-budget components indicate an 80-million-gallon-per-day decrease in pumping from the Floridan aquifer system during this period.

Georgia↗
USGS2019

Results from the Department of the Interior Strategic Sciences Group Technical Support for the 2018 Kīlauea Eruption

On May 3, 2018 Hawai'i’s Kīlauea volcano erupted, ultimately covering 35 square kilometers (13.5 square miles) of land in lava, destroying over 700 homes in multiple subdivisions, and displacing over 2500 residents in the Puna District on the southeast flank of the volcano. Simultaneously, Kīlauea’s summit experienced its largest collapse in 200 years, with a total of 500 meters (1,640 feet) subsidence and tens of earthquakes each day rattling surrounding communities. These simultaneous events impacted residential, agricultural, business, tourist, and scientific areas. Hawai'i Volcanoes National Park closed, slowing tourism and the local economy. The building housing the United States Geological Survey (USGS) Hawai'ian Volcano Observatory also closed, displacing scientists responsible for monitoring the erupting volcano. The eruption lasted 107 days, one of the longest eruptions in recent history in lower Puna. Throughout the eruption, uncertainty regarding the duration of the event, its extent, and total damage remained high. This uncertainty led to social tensions and fatigue across the affected community, responders, and local officials. At the direction of the USGS Director, serving as the Science Advisor to the Secretary of the of the Interior, the Department of the Interior (DOI, hereafter also referred to as “the Department”) Strategic Sciences Group (SSG) convened a multidisciplinary group of 13 experts in Hilo, Hawai'i, on July 17-19, 2018. The SSG was charged with considering the cascading short- and long-term social, economic, and environmental consequences of the 2018 Kīlauea eruption to DOI resources, employees, and facilities as well as to the surrounding communities. Established in 2012, the SSG is designed to complement ongoing response efforts by providing strategic science to identify potential social, environmental, and economic consequences and potential interventions during a crisis event affecting Departmental resources. This activation of the SSG was funded by the USGS. It was the first official activation of the SSG since it supported Hurricane Sandy recovery in 2013 and provided the unique opportunity to test new methods, including bolstering the social science expertise on the team and interacting directly with stakeholders before, during, and after deployment. The SSG Kīlauea Team developed three scenarios focused on 1) the impacts of continued seismicity and deformation at the summit; 2) vog (volcanic smog); and 3) the eruption in the lower East Rift Zone. Across all scenarios, areas of concern included human health (physical and mental); biosecurity (for example, protecting threatened and endangered species); infrastructure (impacts caused by seismic activity, vog, and lava); communications (internal and public-facing); long-term planning (related to tourism, access, housing); and ongoing needs for community engagement and empowerment. The SSG Kīlauea Team identified 59 potential actions for mitigation. Highlights of these actions were delivered to stakeholders during briefings in August and September 2018. Examples of potential actions included: ● Seize opportunities to develop new partnerships within and outside of DOI to address facilities issues caused by seismic damage and park closure. ● Educate community members and new workers to increase early detection of invasive species and establish new wash stations to address biosecurity threats to the park posed by more frequent commuting from new temporary Hilo locations. ● Create a "vog officer" position to ensure coordination and consistency in communication about vog hazards across federal, state, and county agencies. It is important to note that the potential actions are suggestions and are not intended to be prescriptive. The SSG uses “blue sky thinking” when developing these potential actions to encourage creative approaches to problem solving. In some cases, some of the suggested potential actions derived by the SSG are actions that were already underway, or already under consideration and helped to affirm 3 activities by different stakeholders. In other cases, the actions may be new ideas. Some were applicable to immediate response, while others are more relevant to long-term recovery. This report details the results from the July 2018 activation of the SSG. It includes background on Kīlauea and the 2018 eruption, an overview of SSG methodology, and a complete list of the potential actions to mitigate cascading consequences identified by the SSG. Importantly, Appendix 4 includes several rapidly assembled “issue papers” on a variety of topics for consideration for recovery and future preparedness and response activities. This report is designed to be used by both the Department and more broadly by partners, including the Federal Emergency Management Agency, Hawai'i County, Hawai'i Department of Health, and the Hawai'i Emergency Management Agency.

Hawaii↗
USGS2009

Comparison of ASTER- and AVIRIS-derived mineral and vegetation maps of the White Horse replacement alunite deposit and surrounding area, Marysvale volcanic field, Utah

This report presents and compares mineral and vegetation maps of parts of the Marysvale volcanic field in west-central Utah that were published in a recent paper describing the White Horse replacement alunite deposit. Detailed, field-verified maps of the deposit were produced from Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data acquired from a low-altitude Twin Otter turboprop airborne platform. Reconnaissance-level maps of surrounding areas including the central and northern Tushar Mountains, Pahvant Range, and portions of the Sevier Plateau to the east were produced from visible, near-infrared, and shortwave-infrared data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor carried aboard the Terra satellite platform. These maps are also compared to a previously published mineral map of the same area generated from AVIRIS data acquired from the high-altitude NASA ER-2 jet platform. All of the maps were generated by similar analysis methods, enabling the direct comparison of the spatial scale and mineral composition of surface geologic features that can be identified using the three types of remote sensing data. The high spatial (2-17 meter) and spectral (224 bands) resolution AVIRIS data can be used to generate detailed mineral and vegetation maps suitable for geologic and geoenvironmental studies of individual deposits, mines, and smelters. The lower spatial (15-30 meter) and spectral (9 bands) resolution ASTER data are better suited to less detailed mineralogical studies of lithology and alteration across entire hydrothermal systems and mining districts, including regional mineral resource and geoenvironmental assessments. The results presented here demonstrate that minerals and mineral mixtures can be directly identified using AVIRIS and ASTER data to elucidate spatial patterns of mineralogic zonation; AVIRIS data can enable the generation of maps with significantly greater detail and accuracy. The vegetation mapping results suggest that ASTER data may provide an efficient alternative to spectroscopic data for studies of burn severity after wildland fires. A new, semiautomated methodology for the analysis of ASTER data is presented that is currently being applied to ASTER data coverage of large areas for regional assessments of mineral-resource potential and mineral-environmental effects. All maps are presented in a variety of digital formats, including jpeg, pdf, and ERDAS Imagine (.img). The Imagine format files are georeferenced and suitable for viewing with other geospatial data in Imagine, ArcGIS, and ENVI. The mineral and vegetation maps are attributed so that the material identified for a pixel can be determined easily in ArcMap by using the Identify tool and in Imagine by using the Inquire Cursor tool.

Utah↗
USGS2016

Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error

It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because the manual collection of sufficient numbers of suspended-sediment samples required to characterize this variability is often time and cost prohibitive, several “surrogate” techniques have been developed for in situ measurements of properties related to suspended-sediment characteristics (for example, turbidity, laser-diffraction, acoustics). Herein, we present a new physically based method for the simultaneous measurement of suspended-silt-and-clay concentration, suspended-sand concentration, and suspended‑sand median grain size in rivers, using multi‑frequency arrays of single-frequency side‑looking acoustic-Doppler profilers. The method is strongly grounded in the extensive scientific literature on the incoherent scattering of sound by random suspensions of small particles. In particular, the method takes advantage of theory that relates acoustic frequency, acoustic attenuation, acoustic backscatter, suspended-sediment concentration, and suspended-sediment grain-size distribution. We develop the theory and methods, and demonstrate the application of the method at six study sites on the Colorado River and Rio Grande, where large numbers of suspended-sediment samples have been collected concurrently with acoustic attenuation and backscatter measurements over many years. The method produces acoustical measurements of suspended-silt-and-clay and suspended-sand concentration (in units of mg/L), and acoustical measurements of suspended-sand median grain size (in units of mm) that are generally in good to excellent agreement with concurrent physical measurements of these quantities in the river cross sections at these sites. In addition, detailed, step-by-step procedures are presented for the general river application of the method. Quantification of errors in sediment-transport measurements made using this acoustical method is essential if the measurements are to be used effectively, for example, to evaluate uncertainty in long-term sediment loads and budgets. Several types of error analyses are presented to evaluate (1) the stability of acoustical calibrations over time, (2) the effect of neglecting backscatter from silt and clay, (3) the bias arising from changes in sand grain size, (4) the time-varying error in the method, and (5) the influence of nonrandom processes on error. Results indicate that (1) acoustical calibrations can be stable for long durations (multiple years), (2) neglecting backscatter from silt and clay can result in unacceptably high bias, (3) two frequencies are likely required to obtain sand-concentration measurements that are unbiased by changes in grain size, depending on site-specific conditions and acoustic frequency, (4) relative errors in silt-and-clay- and sand-concentration measurements decrease substantially as concentration increases, and (5) nonrandom errors may arise from slow changes in the spatial structure of suspended sediment that affect the relations between concentration in the acoustically ensonified part of the cross section and concentration in the entire river cross section. Taken together, the error analyses indicate that the two-frequency method produces unbiased measurements of suspended-silt-and-clay and sand concentration, with errors that are similar to, or larger than, those associated with conventional sampling methods.

Arizona, Texas↗
USGS1947

Major winter and nonwinter floods in selected basins in New York and Pennsylvania

The scientific design of flood-control works is based on an evaluation of the hydrologic factors basic to flood events, particularly how rainfall and snow runoff, soil conditions, and channel influences can combine to produce greater or lesser floods. For this purpose an analysis of the pertinent hydrologic data is needed. The methods of analysis adopted should conform as closely as possible to those already in use and must be adapted to the quality of the available information. Maximum floods in 8 basins in New York and Pennsylvania during the winter and nonwinter months were studied, a total of 21 floods. The most outstanding winter flood of record in the North Atlantic region was that of March 1936. Rainfall plus snow melt in the basins studied ranged between 3.04 and 6.87 inches, and associated volumes of direct runoff from 1.88 to 5.63 inches. Winter floods have a common characteristic in their relation to freezing temperature. The antecedent periods, representing a period of snow accumulation and frost penetration, are below freezing, and the flood itself is contemporaneous with a period of above-freezing temperatures, usually associated with rain, during which the previously accumulated snow is melted. A second common characteristic of major winter floods is their tendency to be associated with widespread causal meteorologic conditions. There was a more complete conversion of rainfall and snow melt into runoff during the winter storms studied than during the wettest nonwinter flood. Snow melt during winter floods ranged from 0.04 to 0.07 inch per degree-day above 32° F. The depth of mean areal rainfall produced by the nonwinter storms studied ranged from 3.05 to 4.96 inches. The maximum 24-hour quantity at single stations was 14 inches, which was measured during the storm of July 1935 in New York. The volume of direct runoff ranged between 1.39 and 3.41 inches. The portion of rainfall that was converted into runoff varied in accordance with the rate of antecedent base flow, expressed in second-feet per square mile, and emphasized the influence of antecedent conditions. The average volume of direct runoff during winter floods was 4.24 inches, and the average during nonwinter floods was 2.44 inches. The latter, however, were more concentrated as to time, tending to compensate for large volume of runoff in winter, so that the crest rates of direct runoff averaged 0.056 inches per hour during the winter and 0.051 inches during the nonwinter period.

New York, Pennsylvania↗
USGS2009

The Eocene-Oligocene sedimentary record in the Chesapeake Bay impact structure: Implications for climate and sea-level changes on the western Atlantic margin

A multidisciplinary investigation of the Eocene-Oligocene transition in the International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) Eyreville core from the Chesapeake Bay impact basin was conducted in order to document environmental changes and sequence stratigraphic setting. Planktonic foraminifera and calcareous nannofossil biostratigraphy indicate that the Eyreville core includes an expanded upper Eocene (Biozones E15 to E16 and NP19/20 to NP21, respectively) and a condensed Oligocene-Miocene (NP24-NN1) sedimentary sequence. The Eocene-Oligocene contact corresponds to a =3-Ma-long hiatus. Eocene- Oligocene sedimentation is dominated by great diversity and varying amounts of detrital and authigenic minerals. Four sedimentary intervals are identified by lithology and mineral content: (1) A 30-m-thick, smectite- and illite-rich interval directly overlies the Exmore Formation, suggesting long-term reworking of impact debris within the Chesapeake Bay impact structure. (2) Subsequently, an increase in kaolinite content suggests erosion from soils developed during late Eocene warm and humid climate in agreement with data derived from other Atlantic sites. However, the kaolinite increase may also be explained by change to a predominant sediment input from outside the Chesapeake Bay impact structure caused by progradation of more proximal facies belts during the highstand systems tract of the late Eocene sequence E10.Spectral analysis based on gamma-ray and magnetic susceptibility logs suggests infl uence of 1.2 Ma low-amplitude oscillation of the obliquity period during the late Eocene. (3) During the latest Eocene (Biozones NP21 and E16), several lithological contacts (clay to clayey silt) occur concomitant with a prominent change in the mineralogical composition with illite as a major component: This lithological change starts close to the Biozone NP19/20-NP21 boundary and may correspond to sequence boundary E10-E11 as observed in other northwest Atlantic margin sections. It could result from a shift to more distal depositional environments and condensed sedimentation during maximum fl ooding, rather than refl ecting a climatic change in the hinterland. The distinct 1% increase of the oxygen isotopes may correspond to the short-term latest Eocene "precursor isotope event." (4) The abrupt increase of sediment grainsize, carbonate content, and abundance of authigenic minerals (glauconite) across the major unconformity that separates Eocene from Oligocene sediments in the Eyreville core refl ects deposition in shallower settings associated with erosion, winnowing, and reworking. Sediments within the central crater were affected by the rapid eustatic sea-level changes associated with the greenhouse-icehouse transition, as well as by an abrupt major uplift event and possibly enhanced current activity on the northwestern Atlantic margin. ?? 2009 The Geological Society of America.

Chesapeake Bay↗
USGS2014

Methods for estimating magnitude and frequency of floods in Arizona, developed with unregulated and rural peak-flow data through water year 2010

Flooding is among the worst natural disasters responsible for loss of life and property in Arizona, underscoring the importance of accurate estimation of flood magnitude for proper structural design and floodplain mapping. Twenty-four years of additional peak-flow data have been recorded since the last comprehensive regional flood frequency analysis conducted in Arizona. Periodically, flood frequency estimates and regional regression equations must be revised to maintain the accurate estimation of flood frequency and magnitude. Annual peak-flow data collected through water year 2010 were compiled from 448 unregulated streamflow-gaging stations, hereafter referred to as streamgages, in Arizona having a minimum of 10 years of record. Flood frequency estimates were first computed with station (or at-site) skew using the Expected Moments Algorithm with a multiple Grubbs-Beck test to identify multiple potentially influential low flows to fit a Pearson Type III distribution. Next, a multiple step Bayesian least-squares-regression approach was used to determine a new statewide regional skew of −0.09. No basin characteristics analyzed were statistically significant in explaining the variation in skew and as a result, the constant model was chosen as the best regional skew model for the Arizona study area. The mean square error used in Bulletin 17B (B17B) of the Interagency Advisory Committee on Water Data is used to describe the precision of the regional skew. The constant model had a mean square error equal to 0.08, which corresponds to an effective record length of 85 years. This is a marked improvement over a previous Arizona regional skew analysis, with a reported mean square error of 0.31, for a corresponding effective record length of around 17 years. Thus the new regional model had almost five times the information content (as measured by effective record length) of that calculated in USGS Water Supply Paper 2433, published in 1997, or the value of 0.302 reported in the B17B generalized skew map. The flood frequency estimates were recalculated using a weighted skew of the station and regional skew. Station flood frequency estimates for each streamgage are presented for the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities. Geographical information systems were used to compute basin characteristic information for each streamgage for the purpose of developing regional equations to estimate flood statistics at ungaged basins. Five hydrologic flood regions in Arizona were defined in a multivariate regionalization process based on mean basin elevation, mean annual precipitation, and soil permeability. A regional generalized least-squares-regression analysis was used to develop five sets of equations from 344 nonredundant streamgages, corresponding to five regions, for estimating the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities at ungaged basins in Arizona. The regression equations developed for these five regions were based on one or more of the statistically significant explanatory variables: drainage area, mean basin elevation, and mean annual precipitation. Average standard errors of prediction for the regression regions for the five regions ranged from 27 to 122 percent and the pseudo-coefficients of determination (pseudo-R 2 ), a measure of the proportion of peak-flow variation that is explained by the basin characteristics, ranged from 68 to 98 percent. Regression equations for Central Highlands (region 4) had the lowest model error and the greatest pseudo-R 2 metrics. The equations for Colorado Plateau (region 2) regression equations generally had greater model error and lower pseudo-R 2 metrics. The improvement of regional regression equation model error and pseudo-R 2 metrics was related to higher numbers of streamgages, longer period of record, and even spatial coverage within a region. The regional regression equations were integrated into the U.S. Geological Survey’s StreamStats program. The StreamStats program is a national map-based web application that allows the public to easily access published flood frequency and basin characteristic statistics. The interactive web application allows a user to select a point within a watershed (gaged or ungaged) and retrieve flood-frequency estimates derived from the current regional regression equations and geographic information system data within the selected basin. StreamStats provides users with an efficient and accurate means for retrieving the most up to date flood frequency and basin characteristic data. StreamStats is intended to provide consistent statistics, minimize user error, and reduce the need for large datasets and costly geographic information system software.

Arizona↗
USGS2009

Petrographic observations on the Exmore breccia, ICDP-USGS drilling at Eyreville, Chesapeake Bay impact structure, USA

The International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) Eyreville A and B drill cores sampled crater fill in the region of the crater moat, ??9 km to the NE of the center of the Chesapeake Bay impact structure, Virginia, USA. They provide a 953 m section (444-1397 m depth) of sedimentary clast breccia and intercalated sedimentary and crystalline megablocks knownas Exmore beds, deposited on top of the impactite sequence between 1397 and 1551 m depth. We petrographically investigated the sandy-clayey groundmass-dominated breccia, which resembles a diamictite ("Exmore breccia"), and which, in its lower parts, carries sedimentary and crystalline blocks. The entire breccia interval is characterizedby the presence of glauconite and bioclastic carbonate, which distinguishes the Exmore breccia from other sandy facies above and below in the stratigraphy. The sediment-clast breccia exhibits strong heterogeneity from sample to sample with respect to groundmass nature, e.g., clay versus sand content, as well as clast content, in general, and shocked clast content, in particular. There is a consistently signifi cantly larger macroscopic sedimentary to crystalline clast content. On the microscopic scale, the intersample sediment to crystalline clast ratios are quite variable. A very small component of shocked material, in the form of shock-deformed quartz, and to an even lesser degree feldspar, and somewhat more abundant but still relatively scarce shardshaped,altered melt particles, is present throughout the section. However, between ??458 and 469 m, and between 514 and 527 m depths, the abundance of such melt particlesis notably enhanced. These sections are also chemically distinct and relatively more mafic than the other parts of the Exmore breccia. It appears that from the time of deposition of the 527 m material, calming of the ocean occurred over the crater area as a result of abatement of resurge activity, so that ejecta from the plume abovethe crater could accumulate within the crater area to a larger degree. Deposition ofejecta fallout from the collapsing ejecta plume was terminated by the time of deposition of the 458 m material. This raises questions about the positioning of the exact upper contact of Exmore breccia to post-Exmore sediment (Chickahominy Formation), which is currently placed at 444 m depth and which possibly should be revisedto 458 m depth. Based on a signifi cant record of granite-derived material with shocked minerals, the shocked debris component seems to be largely derived from crystalline target rocks. This provides further evidence that the basement-derived material of the basal section of the Eyreville drill cores, which is essentially unshocked, is likely of an allochthonous nature and that the drilling did not intersect the actual crater floor. 76??W. ?? 2009 Geological Society of America.

Special Paper of the Geological Society of America↗
USGS2002

The Effect of Selected Cleaning Techniques on Berkshire Lee Marble: A Scientific Study at Philadelphia City Hall

This report describes a scientific investigation of the effects of eight different cleaning techniques on the Berkshire Lee marble component of the facade of the East Center Pavilion at Philadelphia City Hall; the study was commissioned by the city of Philadelphia. The eight cleaning techniques evaluated in this study were power wash (proprietary gel detergent followed by water rinse under pressure), misting (treatment with potable, nebulized water for 24-36 hours), gommage (proprietary Thomann-Hanry low-pressure, air-driven, small-particle, dry abrasion), combination (gommage followed by misting), Armax (sodium bicarbonate delivered under pressure in a water wash), JOS (dolomite powder delivered in a low-pressure, rotary-vortex water wash), laser (thermal ablation), and dry ice (powdered-dry-ice abrasion delivered under pressure). In our study approximately 160 cores were removed from the building for laboratory analysis. We developed a computer program to analyze scanning-electron-micrograph images for the microscale surface roughness and other morphologic parameters of the stone surface, including the near-surface fracture density of the stone. An analysis of more than 1,100 samples cut from the cores provided a statistical basis for crafting the essential elements of a reduced-form, mixed-kinetics conceptual model that represents the deterioration of calcareous stone in terms of self-organized soiling and erosion patterns. This model, in turn, provided a basis for identifying the variables that are affected by the cleaning techniques and for evaluating the extent to which such variables influence the stability of the stone. The model recognizes three classes of variables that may influence the soiling load on the stone, including such exogenous environmental variables as airborne moisture, pollutant concentrations, and local aerodynamics, and such endogenous stone variables as surface chemistry and microstructure (fracturing, roughness, and so on). This study showed that morphologic variables on the mesoscale to macroscale are not generally affected by the choice of a cleaning technique. The long-term soiling pattern on the building is independent of the cleaning technique applied. This study also showed that soluble salts do not play a significant role in the deterioration of Berkshire Lee marble. Although salts were evident in cracks and fissures of the heavily soiled stone, such salts did not penetrate the surface to a depth of more than a few hundred micrometers. The criteria used to differentiate the cleaning techniques were ultimately based on the ability of each technique to remove soiling without altering the texture of the stone surface. This study identified both the gommage and JOS techniques as appropriate for cleaning ashlar surfaces and the combination technique as appropriate for cleaning highly carved surfaces at the entablatures, cornices, and column capitals.

Professional Paper↗
USGS2003

Irrigation-induced contamination of water, sediment, and biota in the western United States-synthesis of data from the National Irrigation Water Quality Program

In October 1985 the U.S. Department of the Interior (DOI), through the National Irrigation Water Quality Program (NIWQP), began a series of field investigations at 26 areas in the Western United States to determine whether irrigation drainage has had harmful effects on fish, wildlife, and humans or has reduced beneficial uses of water. In 1992 NIWQP initiated the Data Synthesis Project to evaluate data collected during the field investigations. Geologic, climatologic, and hydrologic data were evaluated and water, sediment, and biota from the 26 areas were analyzed to identify commonalities and dominant factors that result in irrigation-induced contamination of water and biota. Data collected for the 26 area investigations have been compiled and merged into a common data base. The structure of the data base is designed to enable assessment of relations between contaminant concentrations in water, sediment, and biota. The data base is available to the scientific community through the World Wide Web at URL http://www.usbr.gov/niwqp. Analysis of the data base for the Data Synthesis included use of summary statistics, factor analysis, and logistic regression. A Geographic Information System was used to store and analyze spatially oriented digital data such as land use, geology and evaporation rates. In the U.S. Department of the Interior (DOI) study areas, samples of water, bottom sediment, and biota were collected for trace-element and pesticide analysis. Contaminants most commonly associated with irrigation drainage were identified by comparing concentrations in water with established criteria. For surface water, the criteria used were typically chronic criteria for the protection of freshwater aquatic life. Because ground water can discharge to the surface where wildlife can be exposed to it, the criteria used for ground water were both the maximum contaminant levels (MCL's) for drinking water and the chronic criteria for the protection of freshwater aquatic life. Data collected by the NIWQP studies indicated that, in surface water, filtered and unfiltered samples had nearly the same concentrations of arsenic, boron, molybdenum, and selenium for concentrations greater than about 10 micrograms per liter. Therefore, in this concentration range, filtered concentrations can be directly compared to biological-effect levels developed for unfiltered samples. In the range of 1 to 10 micrograms per liter there may be a tendency for unfiltered arsenic concentrations to be greater than filtered concentrations. For selenium, however, the data suggest differences from equality in that range result from analytical imprecision and not a general tendency for unfiltered concentrations to be greater than filtered concentrations. This relation may not be true in lentic, nutrient-rich waters because in such settings algae can bioaccumulate large amounts of selenium and other trace elements. Selenium was the trace element in surface water that most commonly exceeded chronic criteria for the protection of freshwater aquatic life; more than 40 percent of the selenium concentrations in surface-water samples exceeded the U.S. Environmental Protection Agency (USEPA) aquatic-life chronic criterion (5 micrograms per liter). In 12 of the 26 areas at least 25 percent of the surface water-samples had selenium concentrations that either equaled or exceeded the chronic criterion (5 micrograms per liter). More than 28 percent of boron concentrations and almost 17 percent of the molybdenum concentrations exceeded the aquatic life criteria established by the State of California (550 and 19 micrograms per liter, respectively). In ground water, more than 22 percent of the arsenic concentrations and more than 35 percent of the selenium concentrations exceeded the MCL (10 and 50 micrograms per liter, respectively). Few samples of uranium in surface water exceeded a criterion for the protection of aquatic life (300 micrograms per liter), but 44 percent

Professional Paper↗
USGS2009

Estimated use of water in Alabama in 2005

Water use in Alabama was about 9,958 million gallons per day (Mgal/d) during 2005. Estimates of withdrawals by source indicate that total surface-water withdrawals were about 9,467 Mgal/d (95 percent of the total withdrawals) and the remaining 491 Mgal/d (5 percent) were from ground water. More surface water than ground water was withdrawn for all categories except aquaculture, mining, and self-supplied residential. During 2005, estimated withdrawals by category and in descending order were: thermoelectric power, 8,274 Mgal/d; public supply, 802 Mgal/d; self-supplied industrial, 550 Mgal/d; irrigation, 161 Mgal/d; aquaculture, 75 Mgal/d; self-supplied residential, 39 Mgal/d; livestock, 28 Mgal/d; and mining, 28 Mgal/d. During 2005, about 83 percent of the water used in Alabama was for thermoelectric power to generate about 114,144 net gigawatt-hours of energy. Almost all of the thermoelectric-power water use (about 8,274 Mgal/d) was from surface water; nearly all of the water (98 percent) was used for once-through cooling, and most of that water was returned to a surface-water source. Public-supply and self-supplied residential withdrawals were about 8 percent of total water withdrawals and about 50 percent of total water withdrawals for all categories excluding thermoelectric power. The combined public-supply and self-supplied residential ground-water withdrawals were about 64 percent of total ground-water withdrawals for Alabama. Public-supply deliveries to residential customers were 41 percent of total public-supply withdrawals, or about 326 Mgal/d; combined industrial and commercial deliveries were 44 percent, or about 355 Mgal/d; and public use and losses accounted for the remaining 15 percent, or about 120 Mgal/d. Self-supplied industrial (550 Mgal/d) and mining (28 Mgal/d) withdrawals were about 6 percent of total water withdrawals and about 33 percent of total water withdrawals for all categories excluding thermoelectric power. Paper and allied products accounted for the largest self-supplied industrial surface-water withdrawals (301 Mgal/d), and chemical and allied products (12 Mgal/d) accounted for the largest ground-water withdrawals. Water withdrawals for the agricultural sector-irrigation (161 Mgal/d), aquaculture (75 Mgal/d), and livestock (28 Mgal/d)-were about 3 percent of total withdrawals and about 16 percent of total withdrawals for all categories excluding thermoelectric power. About 135,800 acres of crops, nursery stock, sod, and golf courses were irrigated in 2005. About 97 percent of these acres were irrigated with sprinkler irrigation systems. The statewide average application rate was 1.33 acre-feet per acre per year. The highest application rate, 3.74 acre-feet per acre per year, was for nursery stock. The largest total water withdrawals by county occurred in Limestone, Jackson, Colbert, and Mobile Counties, and were 60 percent of the total; these withdrawals primarily were used to meet the cooling needs at thermoelectric-power plants. Excluding thermoelectric power, the largest withdrawals by county were in Morgan, Mobile, Jefferson, Talladega, and Madison Counties. Water use was estimated at the hydrologic subbasin level for all categories except aquaculture, mining, and self-supplied residential. The Middle Tennessee-Elk subregion accounted for about 53 percent (5,185 Mgal/d) of the estimated total withdrawals by subbasin of 9,816 Mgal/d. About 92 percent of the water use in the Middle Tennessee-Elk subregion was for thermoelectric power, and more than 99 percent of the water was from surface water. Gross per capita use for all offstream uses was 2,185 gallons per day (gal/d) for the estimated 4.56 million Alabama residents in 2005. Public-supply per capita use was 199 gal/d for the estimated 4.04 million residents served by a public supplier; public-supplied residential per capita use was 81 gal/d. Self-supplied residential per capita use was 75 gal/d for the estimated 0.52 million self-supplied residential population. Average residential per capita use was 80 gal/d. Total water withdrawals decreased less than 1 percent from 9,990 Mgal/d in 2000 to 9,958 Mgal/d in 2005. Surface-water withdrawals decreased less than 5 percent from 9,950 Mgal/d in 2000 to 9,467 Mgal/d in 2005. In contrast, ground-water withdrawals increased about 12 percent from 440 Mgal/d in 2000 to 491 Mgal/d in 2005. By category, increases in irrigation (118 Mgal/d, about 274 percent), thermoelectric power (84 Mgal/d, about 1 percent), and aquaculture (65 Mgal/d, 620 percent) were offset by declines in self-supplied industrial (283 Mgal/d, about 34 percent), self-supplied residential (40 Mgal/d, about 50 percent); and public supply (32 Mgal/d, about 4 percent) from 2000 to 2005. Water use for livestock and mining was not estimated in 2000.

Scientific Investigations Report↗
USGS2012

The Novarupta-Katmai eruption of 1912 - largest eruption of the twentieth century; centennial perspectives

The explosive outburst at Novarupta (Alaska) in June 1912 was the 20th century's most voluminous volcanic eruption. Marking its centennial, we illustrate and document the complex eruptive sequence, which was long misattributed to nearby Mount Katmai, and how its deposits have provided key insights about volcanic and magmatic processes. It was one of the few historical eruptions to produce a collapsed caldera, voluminous high-silica rhyolite, wide compositional zonation (51-78 percent SiO 2 ), banded pumice, welded tuff, and an aerosol/dust veil that depressed global temperature measurably. It emplaced a series of ash flows that filled what became the Valley of Ten Thousand Smokes, sustaining high-temperature metal-transporting fumaroles for a decade. Three explosive episodes spanned ~60 hours, depositing ~17 km 3 of fallout and 11±2 km 3 of ignimbrite, together representing ~13.5 km 3 of zoned magma. No observers were nearby and no aircraft were in Alaska, and so the eruption narrative was assembled from scattered villages and ship reports. Because volcanology was in its infancy and the early investigations (1915-23) were conducted under arduous expeditionary conditions, many provocative misapprehensions attended reports based on those studies. Fieldwork at Katmai was not resumed until 1953, but, since then, global advances in physical volcanology and chemical petrology have gone hand in hand with studies of the 1912 deposits, clarifying the sequence of events and processes and turning the eruption into one of the best studied in the world. To provide perspective on this century-long evolution, we describe the geologic and geographic setting of the eruption - in a remote, sparsely inhabited wilderness; we review the cultural and scientific contexts at the time of the eruption and early expeditions; and we compile a chronology of the many Katmai investigations since 1912. Products of the eruption are described in detail, including eight layers of regionwide fallout, nine packages of ash flows, and three lava domes that followed the explosive pyroclastic episodes. Changes in the proportions of coerupting rhyolite, dacite, and andesite pumice documented for the fallout and ash-flow successions, which are locally interbedded, permit close correlation of those synchronously emplaced sequences and their varied facies. Petrological correlation of the sequence of deposits near Novarupta with ash layers at Kodiak village, 170 km downwind, where three episodes of ashfall were recorded (to the hour), provides key constraints on timing of the eruptive events. Syneruptive collapse of a kilometer-deep caldera took place atop Mount Katmai, a stratovolcano centered 10 km east of the eruption site at Novarupta, owing to drainage of magma from beneath the Katmai edifice. Correlation of ~50 earthquakes recorded at distant seismic stations (including 14 shocks of magnitude 6.0 to 7.0) to fitful caldera collapse provides further constraints on eruption timing, because layers of nonjuvenile breccia and mud ejected from Mount Katmai during collapse pulses are intercalated with the pumice-fall layers from Novarupta. Structure of the Novarupta vent, a 2-km-wide depression backfilled by welded tuff and inferred to be funnel-shaped at depth, is described in detail, as is the 4-km-wide caldera at Mount Katmai. Discussions are also provided concerning: (1) the impact on global climate of the great mass of sulfur-poor but halogen-rich aerosol ejected into the atmosphere by the rhyolite-dominated eruption; (2) chemical and mineralogical effects of the fumarolic acid gases; and (3) the timing of several syneruptive landslide deposits sandwiched within the pumice-fall sequence. Secondary posteruption phenomena characterized include impounded lakes, ash-rich debris flows, phreatic craters on the ignimbrite sheet, responses of glaciers to the fallout blanket and to beheading by caldera collapse, growth of new glaciers inside the caldera, and gradual filling of the caldera lake. Structure, composition, and ages of the several andesite-dacite stratovolcanoes, closely clustered near Novarupta, all of which remain fumarolically and seismically active, are summarized. But among them only Mount Katmai extends compositionally to include basalt and rhyolite. The petrological affinities of 1912 magmas erupted at Novarupta with pre-1912 Katmai lavas are outlined, and various chemical, mineralogical, isotopic, and experimental data are assembled to construct a model of preeruptive magma storage beneath Mount Katmai. The monograph concludes by comparing the 1912 eruption with several other well-studied large explosive eruptions, 14 of them historical and 9 prehistoric. Finally, we retrospectively review the historical difficulties in understanding what had actually taken place at Katmai in 1912 and the century of progress in volcano science that has allowed most of it to be figured out.

Alaska;British Columbia;Washington;Yukon↗
USGS2010

Metallogenesis and Tectonics of Northeast Asia

The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that have been led by the U.S. Geological Survey (USGS). These studies have produced two broad types of publications (1) a series of regional geologic, mineral-deposit, and metallogenic-belt maps, with companion descriptions of the region, and (2) a suite of metallogenic and tectonic analyses of the same region. The study area consists of eastern Russia (most of eastern Siberia and the Russian Far East), Mongolia, northern China, South Korea, Japan, and adjacent offshore areas. The major cooperative agencies are the Russian Academy of Sciences; the Academy of Sciences of the Sakha Republic (Yakutia); VNIIOkeangeologia and Ministry of Natural Resources of the Russian Federation; the Mongolian Academy of Sciences; the Mongolian University of Science and Technology; the Mongolian National University; Jilin University, Changchun, People's Republic of China, the China Geological Survey; the Korea Institute of Geosciences and Mineral Resources; the Geological Survey of Japan/AIST; the University of Texas, Arlington, and the U.S. Geological Survey (USGS). This study builds on and extends the data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera conducted by the USGS, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys, and the Geological Survey of Canada. The major products of this project were summarized by Naumova and others (2006) and are described in appendix A.

Professional Paper↗
USGS2005

Vegetation changes over 12 years in ungrazed and grazed Conservation Reserve Program Grasslands in the central and southern plains

The Conservation Reserve Program (CRP) established under the 1985 Food Security Act has the fundamental objectives of jointly providing economic support to segments of the agricultural community and conservation of natural resources (Osborn, 1997; Heard and others, 2000). Although soil loss on highly erodable lands was the principal natural resource conservation issue addressed in the 1985 CRP, improving water quality and wildlife habitat both became important considerations as the program evolved (Farmer and others, 1988). For example, Best and others (1997) found that production of young birds on CRP fields in the Midwest was ≥15 times the production on row-crop fields because of improved habitat. The increasing importance of wildlife habitat is reflected in continuing refinement of the Environmental Benefits Index (EBI) used by the U.S. Department of Agriculture (USDA) to quantify the potential benefits of enrolling lands in CRP (Osborn, 1997; Ribaudo and others, 2001). The refinements reflect input furnished by federal, state, and non-government organizations seeking greater wildlife habitat quality on CRP lands (Roseberry and David, 1994; Hughes and others, 1995; Millenbah and others, 1996; Patterson and Best, 1996; Rodgers, 1999; Allen and others, 2001). Refinement in the EBI has changed the types of grasses planted on newly enrolled land. In early CRP signups (1 through 11), 71% of new grassland acres were planted to introduced grasses and legumes [Conservation Practice (CP) 1] while 29% of the acres were planted to native grasses (CP2) (Osborn and others, 1992). By the 27th signup in July 2004, over 34.8 million acres (14 million ha) were enrolled in the CRP. More than 73% of these lands were planted to various mixtures of introduced (CP1) or native (CP2) grasses for a minimal contract period of 10 years (USDA, 2004). Continuation of grass plantings under the 2002 Farm Bill may result in CRP lands furnishing grass dominated cover for 20 or more consecutive years. The species of grass established in seeded grasslands can have a major influence on the potential quality of wildlife habitat where vegetation is maintained over a multi-year period. Different species of grass may have comparable abilities to alleviate soil erosion but furnish dissimilar qualities of wildlife habitat (fig. 1). For example, smooth brome, an introduced cool-season grass (grass species and scientific names are presented in table 1), is highly valued for its erosion control and forage attributes (Casler and Carlson, 1995). Switchgrass, a native warm-season grass, also is valued for its soil and water conservation qualities (Moser and Vogel, 1995) but provides greater benefits for some species of wildlife (Clubine, 1995). The quality of nesting and winter cover for ring-necked pheasants (Phasianus colchicus) furnished by smooth brome on northeastern Colorado CRP lands is inferior to that provided by the taller, more robust switchgrass (Allen, 1994). Characteristics of the agricultural landscape surrounding individual CRP fields also play a role in the wildlife habitat potential of CRP plantings (Weber and others, 2002; Nusser and others, 2004). of native and seeded grasslands change in response to the presence (and absence) of physical disturbances such as fire, grazing, tillage, and haying (Hobbs and Huenneke, 1992; Millenbah and others, 1996; Allen and others, 2001; Renfrew and Ribic, 2001; Swengel and Swengel, 2001). The perpetuation of diversity in species composition and vegetation structure following disturbance sustains desirable habitat for a variety of grassland-dependent wildlife (Hall and Willig, 1994; Barnes and others, 1995; King and Savidge, 1995; Granfors and others, 1996; Herkert and others, 1996; Kurzejeski, 1996; Patterson and Best, 1996; Klute and others, 1997). Undisturbed grasslands have lower grass and forb species diversity, greater amounts of dead plant material, decreased as well as seasonally delayed productivity, and diminished structural diversity of vegetation (Peet and others, 1975; Rice and Parenti, 1978; Butler and Briske, 1988; Campa and Winterstein, 1992). Recommendations for the timing of disturbance to increase grass and forb species diversity range from 3 to 8 years following establishment of seeded grasslands in the northern Great Plains and Midwest (Duebbert and others, 1981; Higgens, 1987; Millenbah and others, 1996). The management interval, however, is affected by climatic conditions, soils, grass species, and management history of the individual stand. We quantified changes in vegetation structure and species composition across the typical 10-year contract period in undisturbed southern and central Great Plains CRP fields (fig. 2) planted to introduced and native grasses. In addition, we compared changes in vegetation in fields grazed during the emergency release of 1996 by comparing conditions prior to grazing and two and four years post grazing relative to changes in similar fields that were not grazed. Documentation of long-term changes in vegetation structure and composition for fields planted to common grass seed mixtures across a wide range of environmental conditions provides information to improve long-term wildlife habitat potential, guide program administration, and define management practices that yield economic benefits to operators while still meeting wildlife and conservation objectives. Emergency grazing provisions of the CRP are controversial. Although grazing can alter vegetative characteristics and reduce habitat quality in the short-term (Temple and others, 1999), periodic disturbance may be necessary to maintain habitat quality, and more information is needed assessing long-term effects of emergency grazing on vegetative structure and species composition.

Conference Paper↗
USGS2010

Archean through Mesoproterozoic metallogenesis and tectonics of northeast Asia, Chapter 4 in Metallogenesis and tectonics of northeast Asia

The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that have been led by the U.S. Geological Survey (USGS). These studies have produced two broad types of publications (1) a series of regional geologic, mineral-deposit, and metallogenic-belt maps, with companion descriptions of the region, and (2) a suite of metallogenic and tectonic analyses of the same region. The study area consists of eastern Russia (most of eastern Siberia and the Russian Far East), Mongolia, northern China, South Korea, Japan, and adjacent offshore areas. The major cooperative agencies are the Russian Academy of Sciences; the Academy of Sciences of the Sakha Republic (Yakutia); VNIIOkeangeologia and Ministry of Natural Resources of the Russian Federation; the Mongolian Academy of Sciences; the Mongolian University of Science and Technology; the Mongolian National University; Jilin University, Changchun, People?s Republic of China, the China Geological Survey; the Korea Institute of Geosciences and Mineral Resources; the Geological Survey of Japan/AIST; the University of Texas, Arlington, and the U.S. Geological Survey (USGS). This study builds on and extends the data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera conducted by the USGS, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys, and the Geological Survey of Canada. The major products of this project were summarized by Naumova and others (2006) and are described in appendix A.

Professional Paper↗
USGS2010

Neoproterozoic through Silurian metallogenesis and tectonics of northeast Asia, Chapter 5 in Metallogenesis and tectonics of northeast Asia

The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that have been led by the U.S. Geological Survey (USGS). These studies have produced two broad types of publications (1) a series of regional geologic, mineral-deposit, and metallogenic-belt maps, with companion descriptions of the region, and (2) a suite of metallogenic and tectonic analyses of the same region. The study area consists of eastern Russia (most of eastern Siberia and the Russian Far East), Mongolia, northern China, South Korea, Japan, and adjacent offshore areas. The major cooperative agencies are the Russian Academy of Sciences; the Academy of Sciences of the Sakha Republic (Yakutia); VNIIOkeangeologia and Ministry of Natural Resources of the Russian Federation; the Mongolian Academy of Sciences; the Mongolian University of Science and Technology; the Mongolian National University; Jilin University, Changchun, People?s Republic of China, the China Geological Survey; the Korea Institute of Geosciences and Mineral Resources; the Geological Survey of Japan/AIST; the University of Texas, Arlington, and the U.S. Geological Survey (USGS). This study builds on and extends the data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera conducted by the USGS, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys, and the Geological Survey of Canada. The major products of this project were summarized by Naumova and others (2006) and are described in appendix A.

Professional Paper↗