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USGS2010

Estimation of magnitude and frequency of floods in urban basins in Missouri

Streamgage flood-frequency analyses were done for 35 streamgages on urban streams in and adjacent to Missouri for estimation of the magnitude and frequency of floods in urban areas of Missouri. A log-Pearson Type-III distribution was fitted to the annual series of peak flow data retrieved from the U.S. Geological Survey National Water Information System. For this report, the flood frequency estimates are expressed in terms of percent annual exceedance probabilities of 50, 20, 10, 4, 2, 1, and 0.2. Of the 35 streamgages, 30 are located in Missouri. The remaining five non-Missouri streamgages were added to the dataset to improve the range and applicability of the regression analyses from the streamgage frequency analyses. Ordinary least-squares was used to determine the best set of independent variables for the regression equations. Basin characteristics selected for independent variables into the ordinary least-squares regression analyses were based on theoretical relation to flood flows, literature review of possible basin characteristics, and the ability to measure the basin characteristics using digital datasets and geographic information system technology. Results of the ordinary least-squares were evaluated on the basis of Mallow's Cp statistic, the adjusted coefficient of determination, and the statistical significance of the independent variables. The independent variables of drainage area and percent impervious area were determined to be statistically significant and readily determined from existing digital datasets. The drainage area variable was computed using the best elevation data available, either from a statewide 10-meter grid or high-resolution elevation data from urban areas. The impervious area variable was computed from the National Land Cover Dataset 2001 impervious area dataset. The National Land Cover Dataset 2001 impervious area data for each basin was compared to historical imagery and 7.5-minute topographic maps to verify the national dataset represented the urbanization of the basin at the time streamgage data were collected. Eight streamgages had less urbanization during the period of time streamflow data were collected than was shown on the 2001 dataset. The impervious area values for these eight urban basins were adjusted downward as much as 23 percent to account for the additional urbanization since the streamflow data were collected. Weighted least-squares regression techniques were used to determine the final regression equations for the statewide urban flood-frequency equations. Weighted least-squares techniques improve regression equations by adjusting for different and varying lengths in streamflow records. The final flood-frequency equations for the 50-, 20-, 10-, 4-, 2-, 1-, and 0.2-percent annual exceedance probability floods for Missouri provide a technique for estimating peak flows on urban streams at gaged and ungaged sites. The applicability of the equations is limited by the range in basin characteristics used to develop the regression equations. The range in drainage area is 0.28 to 189 square miles; range in impervious area is 2.3 to 46.0 percent. Seven of the 35 selected streamgages were used to compare the results of the existing rural and urban equations to the urban equations presented in this report for the 1-percent annual exceedance probability. Results of the comparison indicate that the estimated peak flows for the urban equation in this report ranged from 3 to 52 percent higher than the results from the rural equations. Comparing the estimated urban peak flows from this report to the existing urban equation developed in 1986 indicated the range was 255 percent lower to 10 percent higher. The overall comparison between the current (2010) and 1986 urban equations indicates a reduction in estimated peak flow values for the 1-percent annual exceedance probability flood.

Missouri↗
USGS1985

Geology of the Precambrian rocks of the Jabal Habashi Quadrangle, sheet 26F, Kingdom of Saudi Arabia

The Jabal Habashi quadrangle contains formations of Lower Paleozoic and Cenozoic age, unconformably overlying part of the Precambrian Arabian Shield. The Precambrian formations include metamorphosed and strongly deformed volcanic and volcaniclastic rocks and plutons of calc-alkalic, mafic to intermediate composition, dated at about 645 Ma. These are unconformably overlain by the Maraghan formation of the Murdama group, composed of sandstone and siltstone deposited in a vast sedimentary basin present in the region between about 640 to 620 Ma. On the northwestern margin of this large basin, a smaller, fault-controlled basin was filled by the Hibshi formation, a sequence of conglomerate, sandstones, tuffs and minor lava flows, which dates from 632 Ma. Other volcanic rocks from this period probably accumulated around caldera-like volcanoes. The deposition of the Maraghan and Hibshi formations was interrupted by moderate deformation and metamorphism. About 617 Ma ago, the region was intruded by many granodiorite, granite and subordinate gabbro, diorite and peralkaline granite plutons. Gold-bearing quartz veins formed as a result of this intrusive event. A gap in the geologic record of nearly 40 Ma followed, ended by the emplacement of more evolved syenogranite and alkali-feldspar granite plutons. Hydrothermal alteration of one of these granites led to the formation of tin greisen; other granites contain anomalous amounts of rare-earth elements. The stable rock mass created by these geologic processes was extensively eroded at the end of the Precambrian, and was subsequently covered by flat-lying Lower Paleozoic clastic rocks, the Saq Sandstone of Cambrian (?) to early Ordovician age, and the Tabuk Formation, largely siltstone and claystone, of early Ordovician to early Silurian age. Another major gap in the record, extending from the early Paleozoic to late Cenozoic, ended by the extrusion of basaltic lava flows and cinder cones in the northern part of the quadrangle, about 1.8 Ma ago. The volcanic activity, preceded by tilting of the region and the stripping back of the Paleozoic rocks to expose the Precambrian again, was linked to rifting in the Arabian Shield and the opening of the Red Sea. The final event in the quadrangle was the onset of the present-day type of climate and erosion pattern, leading to the development of drainage channels partly filled by sand and small sabkhah deposits, and surfaces covered by recently cemented gravels.

Open-File Report↗
USGS1964

Magnetic properties of Pd, Pd-H and Pd-D from 300 degrees K to 4.2 degrees K

The magnetic properties of many substances first studied seriously by Faraday have played an important role in our modern technology. In particular, the magnetic properties of the transition elements are of great importance in the understanding of the electronic band form of these elements. Once the electronic band form is known, many of the physical properties may be predicted. Although many investigations have been made of the magnetic properties of palladium, no recent measurements have been reported at temperatures lower than 20° K. There is some discrepancy between the earlier work of Onnes and Oosterhuis (1913, 1914) and the later work of Hoare and Matthews (1952). There is reason to believe that the later work is correct because of the purity of the samples, but the data indicate a necessity for measurements at temperatures below 20° K. Palladium adsorbs enormous amounts of hydrogen and a study of this effect could lead to information which would be valuable in the interpretation of the magnetic properties of palladium. The magnetic susceptibility of hydrogenized palladium was studied first by Graham (1869). Since that time it has been shown by Svensson (1953) that the susceptibility of palladium diminishes linearly with increasing hydrogen content and finally reaches a value just below zero for a H/pd volume ratio of 800/1. This same effect was shown to occur by Sieverts and Danz (1937) when deuterium is substituted for hydrogen. Recently, Wucher (1952) has made a study of the variation of the susceptibility of hydrogenized palladium with temperature from -98.6° C to 16.3° C. However, later measurements of the resistivity and thermoelectric power of hydrogenized palladium by Schindler and Smith (1979) indicate that there might be a magnetic anomaly in hydrogenized palladium at 40° K. The purpose of this work is to extend the previous measurements down to 4.2° K, but measurements will be made on desorbed as well as adsorbed samples of hydrogenized and deuterized palladium. The results on the desorbed samples turned out to be quite interesting and suggest further experiments.

Open-File Report↗
USGS1976

Heat flow near Charleston, South Carolina

As part of a study of the geology and geophysics of the Charleston, South Carolina, area, thermal conductivity, thermal gradient, and heat flow were determined in a 742 meter, continuously cored, test hole. The hole is located 41 km west-northwest of Charleston near Clubhouse Corners, Figure 1, directly over a gravity and magnetic high and the possible hypocenter of the 1889 Charleston earthquake. Drilling began January 13, 1975, and the hole penetrated 750 meters of Cenozoic and Upper Cretaceous sedimentary rocks finally bottoming in 42 meters of amygdaloidal basalts. Core recovery was 70% in sedimentary formations and 100% in the basalts. Detailed systematic studies of the core and the area surrounding the borehole were presented at the Symposium: Geology and Geophysics of Charleston, South Carolina, Area, held at the annual meeting of the Northeastern and Southeastern sections of the Geological Society of America during the week of March 25-27, 1976. Results from the thermal study are summarized in this report.

South Carolina↗
USGS2019

Improving eDNA yield and inhibitor reduction through increased water volumes and multi-filter isolation techniques

To inform management and conservation decisions, environmental DNA (eDNA) methods are used to detect genetic material shed into the water by imperiled and invasive species. Methodological enhancements are needed to reduce filter clogging, PCR inhibition, and false-negative detections when eDNA is at low concentrations. In the first of three simple experiments, we sought to ameliorate filter clogging from particulates and organic material through a scaled-up, multi-filter protocol. We combined four filters in a 5 mL Phenol-Chloroform-Isoamyl (PCI) procedure to allow for larger volumes of water (~1 L) to be filtered rapidly. Increasing the filtered water volume by four times resulted in 4.4X the yield of target DNA. Next, inhibition from organic material can reduce or block eDNA detections in PCR-based assays. To remove inhibitory compounds retained during eDNA isolation, we tested three methods to chemically strip inhibitors from eDNA molecules. The use of CTAB as a short-term (5–8 day) storage buffer, followed by a PCI isolation, resulted in the highest eDNA yields. Finally, as opposed to a linear relationship among increasing concentrations of filtered genomic eDNA, we observed a sharp change between the lower (70–280 ng) and higher (420–560 ng) amounts. This may be important for effectively precipitating eDNA during protocol testing.

Scientific Reports↗
USGS2020

Divergent genes encoding the putative receptors for growth hormone and prolactin in sea lamprey display distinct patterns of expression

Growth hormone receptor (GHR) and prolactin receptor (PRLR) in jawed vertebrates were thought to arise after the divergence of gnathostomes from a basal vertebrate. In this study we have identified two genes encoding putative GHR and PRLR in sea lamprey (Petromyzon marinus) and Arctic lamprey (Lethenteron camtschaticum), extant members of one of the oldest vertebrate groups, agnathans. Phylogenetic analysis revealed that lamprey GHR and PRLR cluster at the base of gnathostome GHR and PRLR clades, respectively. This indicates that distinct GHR and PRLR arose prior to the emergence of the lamprey branch of agnathans. In the sea lamprey, GHR and PRLR displayed a differential but overlapping pattern of expression; GHR had high expression in liver and heart tissues, whereas PRLR was expressed highly in the brain and moderately in osmoregulatory tissues. Branchial PRLR mRNA levels were significantly elevated by stage 5 of metamorphosis and remained elevated through stage 7, whereas levels of GHR mRNA were only elevated in the final stage (7). Branchial expression of GHR increased following seawater (SW) exposure of juveniles, but expression of PRLR was not significantly altered. The results indicate that GHR and PRLR may both participate in metamorphosis and that GHR may mediate SW acclimation.

Scientific Reports↗
USGS2004

User's manual for the national water information system of the U.S. Geological Survey: Ground-water site-inventory system

The Ground-Water Site-Inventory (GWSI) System is a ground-water data storage and retrieval system that is part of the National Water Information System (NWIS) developed by the U.S. Geological Survey (USGS). The NWIS is a distributed water database in which data can be processed over a network of workstations and file servers at USGS offices throughout the United States. This system comprises the GWSI, the Automated Data Processing System (ADAPS), the Water-Quality System (QWDATA), and the Site-Specific Water-Use Data System (SWUDS). The GWSI System provides for entering new sites and updating existing sites within the local database. In addition, the GWSI provides for retrieving and displaying ground-water and sitefile data stored in the local database. Finally, the GWSI provides for routine maintenance of the local and national data records. This manual contains instructions for users of the GWSI and discusses the general operating procedures for the programs found within the GWSI Main Menu.

Open-File Report↗
USGS2005

User's Manual for the National Water Information System of the U.S. Geological Survey: Ground-water site-inventory system

The Ground-Water Site-Inventory (GWSI) System is a ground-water data storage and retrieval system that is part of the National Water Information System (NWIS) developed by the U.S. Geological Survey (USGS). The NWIS is a distributed water database in which data can be processed over a network of workstations and file servers at USGS offices throughout the United States. This system comprises the GWSI, the Automated Data Processing System (ADAPS), the Water-Quality System (QWDATA), and the Site- Specific Water-Use Data System (SWUDS). The GWSI System provides for entering new sites and updating existing sites within the local database. In addition, the GWSI provides for retrieving and displaying groundwater and Sitefile data stored in the local database. Finally, the GWSI provides for routine maintenance of the local and national data records. This manual contains instructions for users of the GWSI and discusses the general operating procedures for the programs found within the GWSI Main Menu.

Open-File Report↗
USGS1954

Some unreliable types of ground-water observation wells

Several primary requirements must be fulfilled by any observation well that is to be used as an indicator of ground-water levels over considerable distances. First of all, the water level inside the well must be the same as that outside of the well. the water level inside the well must be able to adjust to water -level fluctuations in the aquifer within a certain period of time, that time dependent upon the type of study for which the observations are to be used. Finally, to be of value in most areal studies, the water level outside the well must be representative of the level throughout the aquifer, and not reflect merely some speical local condition. Should any of these requirements remain unsatisfied, the derived data may be misleading.

Open-File Report↗
USGS2007

Facing tomorrow’s challenges—U.S. Geological Survey science in the decade 2007–2017

Executive Summary In order for the U.S. Geological Survey (USGS) to respond to evolving national and global priorities, it must periodically reflect on, and optimize, its strategic directions. This report is the first comprehensive science strategy since the early 1990s to examine critically major USGS science goals and priorities. The development of this science strategy comes at a time of global trends and rapidly evolving societal needs that pose important natural-science challenges. The emergence of a global economy affects the demand for all resources. The last decade has witnessed the emergence of a new model for managing Federal lands—ecosystem-based management. The U.S. Climate Change Science Program predicts that the next few decades will see rapid changes in the Nation’s and the Earth’s environment. Finally, the natural environment continues to pose risks to society in the form of volcanoes, earthquakes, wildland fires, floods, droughts, invasive species, variable and changing climate, and natural and anthropogenic toxins, as well as animal-borne diseases that affect humans. The use of, and competition for, natural resources on the global scale, and natural threats to those resources, has the potential to impact the Nation’s ability to sustain its economy, national security, quality of life, and natural environment. Responding to these national priorities and global trends requires a science strategy that not only builds on existing USGS strengths and partnerships but also demands the innovation made possible by integrating the full breadth and depth of USGS capabilities. The USGS chooses to go forward in the science directions proposed here because the societal issues addressed by these science directions represent major challenges for the Nation’s future and for the stewards of Federal lands, both onshore and offshore. The six science directions proposed in this science strategy are summarized in the following paragraphs. The ecosystems strategy is listed first because it has a dual nature. It is itself an essential direction for the USGS to pursue to meet a pressing national and global need, but ecosystem-based approaches are also an underpinning of the other five directions, which all require ecosystem perspectives and tools for their execution. The remaining strategic directions are listed in alphabetical order.

Circular↗
USGS1995

Some fluid-inclusion measurements for geothermal drill holes in California, Nevada, El Salvador, and Russia

The purpose of this report is to make available fluid-inclusion information from drill holes in five geothermal areas: The Geysers and Long Valley caldera in northern California; Steamboat Springs, Nevada; the Ahuachapan field of El Salvador, Central America; and the Mutnovsky geothermal field, Kamchatka Peninsula, Russia. These data were produced at the request of various individuals to provide needed subsurface-temperature data for their investigations. The fluid-inclusion information presented in this report has not been previously published, and, since the author did not work in these geothermal areas, only a very minimal attempt is made at interpreting the data. Information on the location of the drill holes from which the core specimens originated ranges from very poor in the case of the Russian drill holes to very good for those in the USA. Mineral specimens from drill-core samples in the five geothermal areas were utilized as cleavage chips, thin sections polished on a single side, or double polished thin sections (polished on both sides). Fluid inclusions from all three USA geothermal areas were found in either hydrothermal or primary quartz crystals. These fluid inclusions firstly were frozen and gradually thawed to determine the final melting-point temperatures (Tm) as the last piece of ice melted and secondly, were heated to the temperature at which the vapor phase disappeared to obtain homogenization temperatures (Tn). For the El Salvador and Russian core specimens the fluid inclusions were hosted in calcite, and the order of the two procedures was reversed because calcite is a much softer mineral than quartz and there is a greater danger of the fluid inclusions decrepitating as the ice expands during freezing. A Chaixmeca microthermometry apparatus was used during studies of the Steamboat Springs and The Geysers fluid inclusions. For the remaining studies, a Linkam THM 600 heating/freezing stage and TMS 90 temperature control system were employed. Accuracy of the data generated from both instruments is similar, with values of about ±2°C for heating studies and about ±0.2°C for the freezing methods.

Open-File Report↗
USGS2001

Preliminary evaluation of the importance of existing hydraulic-head observation locations to advective-transport predictions, Death Valley regional flow system, California and Nevada

When a model is calibrated by nonlinear regression, calculated diagnostic statistics and measures of uncertainty provide a wealth of information about many aspects of the system. This report presents a method of ranking the likely importance of existing observation locations using measures of prediction uncertainty. It is suggested that continued monitoring is warranted at more important locations, and unwarranted or less warranted at less important locations. The report develops the methodology and then demonstrates it using the hydraulic-head observation locations of a three-layer model of the Death Valley regional flow system. The predictions of interest are subsurface transport from beneath Yucca Mountain and 14 Underground Test Areas. The advective component of transport is considered because it is the component most affected by the system dynamics represented by the scale model being used. The problem is addressed using the capabilities of the U.S. Geological Survey computer program MODFLOW-2000, with its ADVective-Travel Observation (ADV) Package, and an additional computer program developed for this work. The methods presented in this report are used in three ways. (1) The ratings for individual observations are obtained by manipulating the measures of prediction uncertainty, and do not involve recalibrating the model. In this analysis, observation locations are each omitted individually and the resulting increase in uncertainty in the predictions is calculated. The uncertainty is quantified as standard deviations on the simulated advective transport. The increase in uncertainty is quantified as the percent increase in the standard deviations caused by omitting the one observation location from the calculation of standard deviations. In general, observation locations associated with larger increases are rated as more important. (2) Ratings for largely geographically based groups are obtained using a straightforward extension of the method used for individual observation locations. This analysis is needed where observations are clustered to determine whether the area is important to the predictions of interest. (3) Finally, the method is used to evaluate omitting a set of 100 observation locations. The locations were selected because they had low individual ratings and were not one of the few locations at which hydraulic heads from deep in the system were measured. The major results of the three analyses, when applied to the three-layer DVRFS ground-water flow system, are described in the following paragraphs. The discussion is labeled using the numbers 1 to 3 to clearly relate it to the three ways the method is used, as listed above. (1) The individual observation location analysis indicates that three observation locations are most important. They are located in Emigrant Valley, Oasis Valley, and Beatty. Of importance is that these and other observations shown to be important by this analysis are far from the travel paths considered. This displays the importance of the regional setting within which the transport occurs, the importance of including some sites throughout the area in the monitoring network, and the importance of including sites in these areas in particular. The method considered in this report indicates that the 19 observation locations that reflect hydraulic heads deeper in the system (in model layers 1, 2, and 3) are not very important. This appears to be because the locations of these observations are in the vicinity of shallow observation locations that also generally are rated as low importance, and because the model layers are hydraulically well connected vertically. The value of deep observations to testing conceptual models, however, is stressed. As a result, the deep observations are rated higher than is consistent with the results of the analysis presented, and none of these observations are omitted in the scenario discussed under (3) below. (2) The geographic grouping of the observations found one major area of importance not identified by the individual observation analysis. Five of the 49 groups are categorized as most highly important. The most important groups were those that, when omitted, produced mean increases greater than 10 percent at any UGTA site or Yucca Mountain. Four of the five groups were dominated by one individual observation. However, one group, located in Ash Meadows, had no individual observations ranked of high importance but collectively, when omitted, increased uncertainty substantially. Other groups also located in Ash Meadows, including intermediate depth observations, consistently ranked as more important than all other groups. (3) To demonstrate the importance of omitting a set of low-rated observations, one scenario is considered in which the 100 individually lowest-rated shallow and intermediate-depth observation locations are omitted. The measure of overall prediction uncertainty increased by just 0.59 percent, indicating that the wells associated with these observations probably could prudently be measured less frequently.

California, Nevada↗
USGS1985

Maps showing sea-floor topography, depth to bedrock, and sediment thickness, Penobscot Bay, Maine

This report presents results of a high-resolution seismic-reflection survey conducted by the U.S. Geological Survey to determine the subbottom characteristics of Penobscot Bay, Maine. Penobscot Bay is one of the major embayments along the U.S. Atlantic coast (fig. 1), extending more than 50 km from the Gulf of Maine to the mouth of the Penobscot River. The bay constitutes an area of about 1,100 km" and is divided into three main passages by numerous islands. The bay and surrounding coastal area have had a complex history of glaciation and sea-level change since late Wisconsinan time. The last ice sheet advanced across the area about 20,000 years ago, eroding the bedrock surface, removing most older sediments, and isostatically depressing the crust (Schafer and Hartshorn, 1965; Stuiver and Borns, 1975; Thompson, 1979). Deglaciation followed between about 12,700–13,500 years ago and was accompanied by a marine transgression (because of crustal depression), with ice and sea in contact (Stuiver and Borns, 1975; Thompson, 1979, 1982; Smith, 1982). Isostatic recovery of the crust then caused the coast to emerge during the immediate postglacial period, and emergence was completed by about 11,500 years ago (Stuiver and Borns, 1975; Thompson, 1979, 1982; Thompson and Smith, 1983). Finally, resubmergence of the Maine coast has accompanied the Holocene rise of sea level that began about 9,000 to 11,000 years ago (Bloom, 1963; Kaye and Barghoorn, 1964; Schmitker, 1974; Oldale and others, 1983). In the maps presented here, we illustrate and briefly describe the sea-floor topography, bedrock morphology, and variable sediment thickness within Penobscot Bay that were either produced or modified during the period of geologic change since late Wisconsinan time.

Maine↗
USGS1995

Thermodynamics of gas and steam-blast eruptions

Eruptions of gas or steam and non-juvenile debris are common in volcanic and hydrothermal areas. From reports of non-juvenile eruptions or eruptive sequences world-wide, at least three types (or end-members) can be identified: (1) those involving rock and liquid water initially at boiling-point temperatures (‘boiling-point eruptions’); (2) those powered by gas (primarily water vapor) at initial temperatures approaching magmatic (‘gas eruptions’); and (3) those caused by rapid mixing of hot rock and ground- or surface water (‘mixing eruptions’). For these eruption types, the mechanical energy released, final temperatures, liquid water contents and maximum theoretical velocities are compared by assuming that the erupting mixtures of rock and fluid thermally equilibrate, then decompress isentropically from initial, near-surface pressure (≤10 MPa) to atmospheric pressure. Maximum mechanical energy release is by far greatest for gas eruptions (≤∼1.3 MJ/kg of fluid-rock mixture)-about one-half that of an equivalent mass of gunpowder and one-fourth that of TNT. It is somewhat less for mixing eruptions (≤∼0.4 MJ/kg), and least for boiling-point eruptions (≤∼0.25 MJ/kg). The final water contents of crupted boiling-point mixtures are usually high, producing wet, sloppy deposits. Final erupted mixtures from gas eruptions are nearly always dry, whereas those from mixing eruptions vary from wet to dry. If all the enthalpy released in the eruptions were converted to kinetic energy, the final velocity ( v max ) of these mixtures could range up to 670 m/s for boiling-point eruptions and 1820 m/s for gas eruptions (highest for high initial pressure and mass fractions of rock ( m r ) near zero). For mixing eruptions, v max ranges up to 1150 m/s. All observed eruption velocities are less than 400 m/s, largely because (1) most solid material is expelled when m r is high, hence v max is low; (2) observations are made of large blocks the velocities of which may be less than the average for the mixture; (3) heat from solid particles is not efficiently transferred to the fluid during the eruptions; and (4) maximum velocities are reduced by choked flow or friction in the conduit.

Bulletin of Volcanology↗
USGS1999

Reintroduction of lake sturgeon in the St. Louis River, western Lake Superior

Lake sturgeon Acipenser fulvescens declined in abundance in Lake Superior's St. Louis River during the late 1800s and were eliminated from the river during the early 1900s because of the combined effects of exploitation, pollution, and habitat alteration. Since then, exploitation in the river and in Lake Superior has been reduced. Furthermore, water quality in the St. Louis River has improved, and its upper-estuary spawning habitat has remained relatively unchanged and adequate. Lake sturgeon have been stocked annually in the St. Louis River since 1983; from 1983 to 1994 stockings included 736,000 fry, 128,000 fingerlings, and 500 yearlings of the Lake Winnebago strain. Relative abundance, distribution, and growth were determined by sampling marked fish in the St. Louis River estuary and western Lake Superior with graded-mesh gill nets and bottom trawls. During 1983–1998, 644 lake sturgeon were caught in 15,486 m of gill net, and 196 were caught in 1,200 trawl tows. Lake sturgeon were sampled most frequently near channelized portions of the St. Louis River and stayed in the estuary up to 5 years before entering Lake Superior. Lake sturgeon were not captured in western Lake Superior prior to stocking, but abundance increased dramatically after 1985. Of 582 lake sturgeon sampled along the Wisconsin shore of Lake Superior from 1985 through 1998 (347,000 m of gill nets), 93% were captured in less than 30 m of water. A total of 93 lake sturgeon were reported from assessment netting conducted along the Minnesota shore of Lake Superior from 1992 through 1997. The current range of stocked lake sturgeon extends from the St. Louis River 145 km east to the apostle Islands in Wisconsin and 110 km northeast to Little Marais in Minnesota. Increases in lake sturgeon abundance were directly attributed to the stocking program. We recommend stocking a minimum of 20 year-classes and the use of a Lake Superior egg source, if possible. Final evaluation of the project will be detection of tagged lake sturgeon successfully spawning at historical spawning areas.

North American Journal of Fisheries Management↗
USGS2007

Modal Composition and Age of Intrusions in North-Central and Northeast Nevada

Introduction Data presented in this report characterize igneous intrusions of north-central and northeast Nevada and were compiled as part of the Metallogeny of the Great Basin project conducted by the U.S. Geological Survey (USGS) between 2001 and 2007. The compilation pertains to the area bounded by lats 38.5 and 42 N., long 118.5 W., and the Nevada-Utah border (fig. 1). The area contains numerous large plutons and smaller stocks but also contains equally numerous smaller, shallowly emplaced intrusions, including dikes, sills, and endogenous dome complexes. Igneous intrusions (hereafter, intrusions) of multiple ages are major constituents of the geologic framework of north-central and northeast Nevada (Stewart and Carlson, 1978). Mesozoic and Cenozoic intrusions are particularly numerous and considered to be related to subduction along the west edge of the North American plate during this time. Henry and Ressel (2000) and Ressel and others (2000) have highlighted the association between magmatism and ore deposits along the Carlin trend. Similarly, Theodore (2000) has demonstrated the association between intrusions and ore deposits in the Battle Mountain area. Decades of geologic investigations in north-central and northeast Nevada (hereafter, the study area) demonstrate that most hydrothermal ore deposits are spatially, and probably temporally and genetically, associated with intrusions. Because of these associations, studies of many individual intrusions have been conducted, including those by a large number of Master's and Doctoral thesis students (particularly University of Nevada at Reno students and associated faculty), economic geologists working on behalf of exploration and mining companies, and USGS earth scientists. Although the volume of study area intrusions is large and many are associated with ore deposits, no synthesis of available data that characterize these rocks has been assembled. Compilations that have been produced for intrusions in Nevada pertain to relatively restricted geographic areas and (or) do not include the broad array of data that would best aid interpretation of these rocks. For example, Smith and others (1971) presented potassium-argon geochronologic and basic petrographic data for a limited number of intrusions in northcentral Nevada. Similarly, Silberman and McKee (1971) presented potassium-argon geochronologic data for a significant number of central Nevada intrusions. More recently, Mortensen and others (2000) presented uranium-lead geochronology for a small number of central Nevada intrusions. Sloan and others (2003) released a national geochronologic database that contains age determinations made prior to 1991 for rocks of Nevada. Finally, C.D. Henry (Nevada Bureau of Mines and Geology, written commun., 2006) has assembled geochronologic data for igneous rocks of Nevada produced subsequent to completion of the Sloan and others (2003) compilation. Consequently, although age data for igneous rocks of Nevada have been compiled, data pertaining to other features of these rocks have not been systematically synthesized. Maldonado and others (1988) compiled the distribution and some basic characteristics of intrusions throughout Nevada. Lee (1984), John (1983, 1987, and 1992), John and others (1994), and Ressel (2005) have compiled data that partially characterize intrusions in some parts of the study area. This report documents the first phase of an effort to compile a robust database for study area intrusions; in this initial phase, modal composition and age data are synthesized. In the next phase, geochemical data available for these rocks will be compiled. The ultimate goal is to compile data as a basis for an evaluation of the time-space-compositional evolution of Mesozoic and Cenozoic magmatism in the study area and identification of genetic associations between magmatism and mineralizing processes in this region.

Data Series↗
USGS2007

Site Report for USGS Test Holes Drilled at Cape Charles, Northampton County, Virginia, in 2004

The U.S. Geological Survey drilled two test holes near Cape Charles, Virginia, during May and June 2004, as part of an investigation of the buried, late Eocene Chesapeake Bay impact structure. The first hole is designated as the USGS-Sustainable Technology Park test hole #1 (USGS-STP1). This test hole was abandoned at a depth of 300 ft; cuttings samples were collected, but no cores or geophysical logs were acquired. The second hole is designated as the USGS-Sustainable Technology Park test hole #2 (USGS-STP2). This test hole was drilled to a depth of 2,699 ft. Cores were collected between depths of 1,401.7 ft and 1,420.7 ft and between 2,440.0 ft and 2,699.0 ft. Cuttings samples were collected from the uncored intervals below 280-ft depth. Interim sets of geophysical logs were acquired during the drilling operation, and one final set was acquired at the end of drilling. Two wells were installed in the USGS-STP2 test hole. The deep well (designated 62G-24) was screened between 2,260 ft and 2,280 ft, and the shallow well (designated 62G-25) was screened between 1,360 ft and 1,380 ft. Ground-water salinities stabilized at 40 parts per thousand for the deep well and 20 parts per thousand for the shallow well. The geologic section encountered in the test holes consists of three main units: (1) Eocene, Oligocene, Miocene, Pliocene, and Pleistocene sands and clays are present between land surface and a depth of 1,163 ft; (2) sediment-clast breccias of the impact structure are present between depths of 1,163 ft and 2,150 ft; and (3) crystalline-clast breccias and cataclastic gneiss of the impact structure are present between depths of 2,150 ft and 2,699 ft.

Open-File Report↗
USGS1963

Chemical analyses of surface waters in Colorado, October 1959 to September 1962

Data presented herein are records of water quality for the period October 1959 to September 1962 for the sampling sites shown below and on the enclosed map. The data are preliminary and subject to revision. Final records are published in the annual series of Geological Survey Water-Supply Papers entitled "Quality of Surface Waters of the United States, " which can be obtained from the Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20242.

Colorado↗