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USGS1998

Preliminary lithostratigraphy, interpreted geophysical logs and hydrogeologic characteristics of the 98th Street core hole, Albuquerque, New Mexico

Core samples, cuttings, and numerous geophysical logs obtained from the 1560 ft (475.5 m) core hole drilled at 98th Street on the west side of Albuquerque provide key stratigraphic and hydraulicproperty information for the upper clastic sediments of the Santa Fe Group, which form the principal aquifer in the region. The core hole and an adjacent water-level monitoring well were drilled cooperatively by the U.S. Geological Survey (USGS) and the City of Albuquerque and investigated in collaboration with the New Mexico Bureau of Mines and Mineral Resources and the New Mexico Office of the State Engineer to improve understanding of aquifer characteristics and controls on ground-water availability and quality. The 751.5 ft (229 m) of core samples recovered from the core hole are the only undisturbed samples of nonlithified sediments of the upper part of the Santa Fe Group that have been collected in this area. These samples have allowed us, for the first time, to directly observe and characterize the lithic and sedimentologic features of this part of the section, and to correlate the detailed geologic features with geophysical-log characteristics, magnetic susceptibility measurements, hydraulic variables, and trace-element geochemistry. The adjacent well was designed to be an areally representative ground-water level and water-quality monitoring well for the Santa Fe Group aquifer. This report chiefly addresses the lithologic, stratigraphic, and hydrogeologic features determined from the 98th Street core hole; other reports address related characteristics. Previous geologic studies predicted the stratigraphy at the site to be, from the land surface downward: 1) Quaternary alluvial and eolian valley-border sediments; 2) fluvial sand and gravel of the upper unit of the Santa Fe Group (Ceja Member of the Santa Fe Formation of Kelly, 1978; equivalent to the Sierra Ledrones Formation of Machette (1978a); 3) downward-fining basin-floor silty clay deposits and 4) fluvial sandy and silty facies of the middle unit of the Santa Fe Group (the Middle Red Member of Bryan and McCann, 1937, and Lambert, 1968). New geologic interpretations indicate that the drill site is in a fault block bounded by east-dipping normal faults and the oblique Atrisco-Rincon fault zone. Core-hole sampling recovered 760.6 ft (231.8 m) of core, in core segments 2.1-2.375 in. (5.3-6 cm) in diameter, and 0.2-10 ft (6.1 cm-3 m) long. The core hole was cased with centered 3-in. PVC casing, and is available for geophysical logging. The monitoring-well hole contains four piezometers at depths of 1544 ft (470.6 m), 1112 ft (338.9 m), 749 ft (228.3 m), and 458 ft (139.6 m). Sediments in the core are loose to weakly cemented gravel, sand, silt, and clay, and lithified sandstone. Laboratory analyses of particle-size distributions of 28 channel samples show that most silty sand samples are uniformly graded and poorly sorted; medium sand samples are moderately sorted. Six principal sediment types are used to describe the core; these sediment types are repeated in various combinations throughout the core and are used to define 22 lithologic units in the cored interval. The six principal sediment types contain sequences of beds having similar modal grain size and sedimentary structure, and are listed in decreasing abundance: 1) Silty fine sand, poorly sorted, containing a coarse silt matrix. Geophysical logs show highly variable baselines with deflections that are related to clay beds and sequences of silt, clay, and sorted fine sand. Density values of 2.12-2.25 g/cc and porosity values of 30-35 percent are typical. 2) Medium sand, moderately to poorly sorted. Geophysical logs show baselines of low variability with deflections that are related to clay beds and sequences of silt, clay, and sorted fine sand. Density values of 2.05-2.20 g/cc and porosity values of 30-35 percent are typical. 3) Clayey sandy silt, poorly sorted, locally microlaminated clay and silt, generally nonplastic. Geophysical logs show highly variable baselines with deflections that are related to sequences of clay and fine sand. Density values of 2.1-2.2 g/cc and porosity values of 30-40 percent are typical. 4) Silt and clay, characteristically red to reddish brown and medium to high plasticity, massive to indistinctly microlaminated. Geophysical logs show variable baselines with broad, high-amplitude compound spikes that are related to sequences of silt and fine sand. Density values of 2.12-2.25 g/cc and porosity values of >45 percent are typical. 5) Sand and gravel, poorly sorted. Geophysical logs show variable baselines with deflections that are related to sequences of silty and sorted fine sand. 6) Sandstone, fine-to-medium grained, poorly sorted, cemented chiefly by calcite, which fills the original pore space. Geophysical logs show density values >2.25 g/cc and porosity values <30 percent. The 22 lithologic units are correlated with recognized basin-floor fluvial lithofacies (Hawley, 1996), which include sand and gravel (lithofacies I), sand with lenses of pebbly sand, silt, and silty clay (lithofacies II), and interbedded sand, silt, and silty clay (modified lithofacies III, IV, IX). The sediments in the core hole are correlated with three informal lithostratigraphic units. The top unit, 0-19 ft (0-5.8 m) depth, consists of Quaternary eolian sand and valley-border alluvium. Coarsegrained deposits in the 19-97 ft (5.8-29.6 m) interval are correlated with the upper unit of the Santa Fe Group. The fine-grained section in the 97-787 ft (29.6-239.9 m) interval is correlated tentatively with the middle unit of the Santa Fe Group. This section contains thick sequences of laminated red and olivebrown clay and silt overbank deposits (441-787 ft) in the distinctive Atrisco member of Connell and others (1998). The Atrisco is correlated with fine-grained zones in numerous wells throughout the central Albuquerque metropolitan area, and is recognized as a zone that separates the upper Santa Fe aquifer from underlying middle Santa Fe deposits. The lower section of the middle unit of the Santa Fe, 787-1500 ft (239.9-457.2 m) depth, includes an upper sequence of moderately sorted channel-fill medium sand, and a lower sequence of sand, silt, and clay overbank deposits. The age of the cored interval is not known precisely. The upper Santa Fe gravel is related regionally to a through-flowing river system that was established in the Rio Grande rift valleys in Early Pliocene time, >4.5 MA. The middle Santa Fe unit is dated tentatively by correlation with a fossiliferous section, in which sandy beds that directly underlie the upper Santa Fe are Late Miocene (Hemphellian), 4.6- 8.9 MA. Further, the middle Santa Fe unit, with dominantly normal magnetic polarity, may have been deposited during closely spaced normal magnetic chrons 5.9-8.3 Ma. Four hydrostratigraphic units summarize the hydrogeologic framework for the 98th Street site: 1) Quaternary valley-border deposits, 2) upper Santa Fe sand and gravel deposits, 3) middle Santa Fe overbank deposits, and 4) middle Santa Fe channel-sand deposits. Empirical values of horizontal hydraulic conductivity estimated from core samples reveal a previously unknown contrast in hydraulic conductivity in the lowest two hydrostratigraphic units. Correlations among numerous wells show that the distinctively fine-grained Atrisco member, with estimated hydraulic conductivities (K) of <0.02-17 ft/day, is a laterally extensive barrier to vertical ground-water flow. The underlying unit that contains moderately sorted medium sand is a potential aquifer production zone that should be investigated further. Laboratory determination of vertical hydraulic conductivity values for fine-grained core samples range from 10 -2 to 10 -7 ft/day; recompacted sandy samples have K values of 1 to 10 -2 ft/day. Results of tests conducted with increasing effective stress show that K values of all samples decrease with decreasing porosity. Comparison of K values from laboratory, empirical, and calculated geophysical values shows discrepancies of 1-3 orders of magnitude (ft/day), indicating that additional analyses of core samples and geophysical data are necessary for future characterization of the Santa Fe Group aquifer.

New Mexico↗

USGS2016

Preliminary geologic mapping of Cretaceous and Tertiary formations in the eastern part of the Little Snake River coal field, Carbon County, Wyoming

In the 1970s and 1980s, C.S. Venable Barclay conducted geologic mapping of areas primarily underlain by Cretaceous coals in the eastern part of the Little Snake River coal field (LSR) in Carbon County, southwest Wyoming. With some exceptions, most of the mapping data were never published. Subsequently, after his retirement from the U.S. Geological Survey (USGS), his field maps and field notebooks were archived in the USGS Field Records. Due to a pending USGS coal assessment of the Little Snake River coal field area and planned geological mapping to be conducted by the Wyoming State Geological Survey, Barclay’s mapping data needed to be published to support these efforts. Subsequently, geologic maps were scanned and georeferenced into a geographic information system, and project and field notes were scanned into Portable Document Format (PDF) files. Data for seventeen 7½-minute quadrangles are presented in this report. This publication is solely intended to compile the mapping data as it was last worked on by Barclay and provides no interpretation or modification of his work.

Wyoming↗

USGS1999

Geological and geophysical setting of the gold-silver vein systems of Unga Island, southwestern Alaska

The topic of this CD-ROM is the geologic framework of gold-silver vein deposits on Unga Island, in the Shumagin Islands, southwestern Alaska. The core of the publication is a new geologic map at a scale of 1:63,360 and aeromagnetic and electromagnetic survey data acquired by industry over the area of mineralization. Both the geologic map as well as a preliminary interpretation of the geophysical data - which are included by permission of the owner - are aimed towards deciphering the relations among volcanism, tectonism, and mineralization. Data and discussions are organized in seven chapters, titles of which are outlined in the table of contents. The chapters consist of viewable text and figure images; postscript versions of the frontispiece figures and all chapter figures are included on the CD-ROM as well. The geologic map is a large viewable figure (Plate 1) that accompanies chapter 2. The map was constructed in ARC and its component coverages are provided in the folder 'Geology' for users who may wish to modify the geologic data or add their own data.

Alaska↗

USGS1986

Reconnaissance of surficial geology, regolith thickness, and configuration of the bedrock surface in Bear Creek and Union Valleys, near Oak Ridge, Tennessee

A preliminary interpretation of the lithology, thickness of regolith, and configuration of the bedrock surface underlying Bear Creek and Union Valleys near Oak Ridge, Tennessee, was made based on geologic and geophysical data from boreholes and cores in Bear Creek Valley and on related work of other investigators. Analysis of drillers ' logs and lithologic logs and comparison of these data with a topographic map indicated that topography and depth of weathering are interdependent and are ultimately controlled by lithology. Topographic patterns were, therefore, used to extend localized geologic data to a larger scale. Maps of the surficial geology, thickness of regolith, and configuration of the bedrock surface are presented. (Author 's abstract)

Water-Resources Investigations Report↗

USGS2014

Geologic implications of gas hydrates in the offshore of India: results of the National Gas Hydrate Program Expedition 01

The Indian National Gas Hydrate Program Expedition 01 (NGHP-01) is designed to study the occurrence of gas hydrate along the passive continental margin of the Indian Peninsula and in the Andaman convergent margin, with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. The NGHP-01 expedition established the presence of gas hydrates in the Krishna-Godavari and Mahanadi Basins, and the Andaman Sea. The expedition discovered in the Krishna-Godavari Basin one of the thickest gas hydrate accumulations ever documented, in the Andaman Sea one of the thickest and deepest gas hydrate stability zones in the world, and established the existence of a fully developed gas hydrate petroleum system in all three basins. The primary goal of NGHP-01 was to conduct scientific ocean drilling/coring, logging, and analytical activities to assess the geologic occurrence, regional context, and characteristics of gas hydrate deposits along the continental margins of India. This was done in order to meet the long-term goal of exploiting gas hydrate as a potential energy resource in a cost effective and safe manner. During its 113.5-day voyage, the D/V JOIDES Resolution cored and/or drilled 39 holes at 21 sites (1 site in Kerala-Konkan, 15 sites in Krishna-Godavari, 4 sites in Mahanadi, and 1 site in the Andaman deep offshore area), penetrated more than 9250 m of sedimentary section, and recovered nearly 2850 m of core. Twelve holes were logged with logging-while-drilling (LWD) tools and an additional 13 holes were wireline logged. The science team utilized extensive on-board laboratory facilities to examine and prepare preliminary reports on the physical properties, geochemistry, and sedimentology of all the data collected prior to the end of the expedition. Samples were also analyzed in additional post-expedition shore-based studies conducted in leading laboratories around the world. One of the specific objectives of this expedition was to test gas hydrate formation models and constrain model parameters, especially those that account for the formation of concentrated gas hydrate accumulations. The necessary data for characterizing the occurrence of in situ gas hydrate, such as interstitial water chlorinities, core-derived gas chemistry, physical and sedimentological properties, thermal images of the recovered cores, and downhole measured logging data (LWD and/or conventional wireline log data), were obtained from most of the drill sites established during NGHP-01. Almost all of the drill sites yielded evidence for the occurrence of gas hydrate; however, the inferred in situ concentration of gas hydrate varied substantially from site to site. For the most part, the interpretation of downhole logging data, core thermal images, interstitial water analyses, and pressure core images from the sites drilled during NGHP-01 indicate that the occurrence of concentrated gas hydrate is mostly associated with the presence of fractures in the sediments, and in some limited cases, by coarser grained (mostly sand-rich) sediments.

Marine and Petroleum Geology↗

USGS1973

Streamflow, sediment, and turbidity in the Mad River basin, Humboldt and Trinity Counties, California

The Mad River discharged an average suspended-sediment load of 2,710,000 tons per year during a 13-year period beginning October 1957. Preliminary analysis of data collected during the 1971 water year indicated that about 66 percent of the suspended sediment was derived from sources upstream from a proposed reservoir site on the Mad River near Butler Valley. The high rate of suspended-sediment discharge and the corresponding sediment-induced turbidity of the streamflow constitute potential problems in the operation of the proposed reservoir. This study is part of an ongoing study by the U.S. Geological Survey intended to determine streamflow, sediment discharge, and turbidity characteristics as they relate to the proposed reservoir and the river system downstream from it. Data from 15 sites in the Mad River basin available through the 1970 water year were reviewed, and the collection of additional data at three of the sites was begun in the 1971 water year. Reconnaissance trips were made in 1971 and 1972 to locate existing or potential problem areas related to sediment and turbidity in the basin. This report presents the interpretations of the data available through September 1971, and indicates the intended direction of the ongoing study.

California↗

USGS1984

Preliminary study of the aquifers of the lower Mesilla Valley in Texas and New Mexico by model simulation

The aquifers in the lower Mesilla Valley of Texas and New Mexico provide water for irrigation, industrial use, and municipal supply. At present (1984), the shallow aquifer is used principally for irrigation. The medium-depth aquifer (the top of which is about 160 to 260 feet below land surface) and deep aquifer (about 460 to 680 feet below land surface) are used almost exclusively by the city of El Paso to provide about 28 percent of the city's ground-water withdrawal of about 82,000 acre-feet in 1980; however, a small percentage of the pumpage is from the shallow aquifer. The potential use of the medium-depth and deep aquifers for irrigation, together with a planned increase in pumping by the city, is causing concern on the part of El Paso water planners over the impact of this development on the limited supply from the two aquifers. A three-dimensional digital model of the aquifers was developed to evaluate the responses of water levels to various plans of development, with particular emphasis on the medium-depth and deep aquifers in and near the Canutillo well field. Simulations also were made to show the effect of eliminating seepage from the Rio Grande to the aquifer system. The model simulations indicate that if pumpage by the city of El Paso during 1^76-80 increases to 10,000 acre-feet, per year from the medium-depth aquifer and to 20,000 acre-feet per year from the deep aquifer, and elsewhere in the study area pumping was held constant at the 1975 rate, then additional lowering of water levels in representative observation wells would be as much as 24 feet in the medium-depth aquifer and as much as 52 feet in the deep aquifer. The water levels would decline sharply during the first few months, after which the levels would become nearly stable because the leakage between the aquifers probably is enough to balance the increased pumpage. The model also indicated that lining of the channel of the Rio Grande would result in an additional lowering of water levels in representative observation wells by 10 feet in the medium-depth aquifer and 8 feet in the deep aquifer. The accuracy of water levels simulated by a model is dependent on the accuracy and distribution of input data and how well model boundary conditions approximate actual boundary conditions. Because of a lack of hydro!ogic data (especial ly water-1 evel information) everywhere except the Canutillo wellfield area, because the simulated cone of depression reached two boundaries, and because the model contained an error and several deficiencies as explained in the "Discussion" section, the simulated results need to be interpreted carefully. The authors believe that the simulated results could be used best as a preliminary and conceptual evaluation of the pumping effects at the Canutillo well field, not as a quantitative interpretation. Although the patterns of simulated hydrographs of water-level change in observation wells in the Canutillo field generally may be correct, the amount of change simulated probably is not correct. Because the salinity of water in all three aquifers south of Canutillo is greater than elsewhere in the study area, there is potential for movement of this water northward toward the Canutillo well field if the cone of depression reaches that part of the aquifer system. This potential should be evaluated in future geohydrologic studies of the lower Mesilla Valley.

New Mexico, Texas↗

USGS1977

Preliminary foraminiferal biostratigraphy and correlation of selected stratigraphic sections and wells in the Gulf of Alaska Tertiary province

As part of ongoing research by the U.S. Geological Survey on the geology and resource potential of the Gulf of Alaska Tertiary Province, a vast amount of data has been accumulated over the past 25 years on the lithology and paleontology of bedded rocks in the province. This report brings together available information on the occurrence, age, and paleoecologic, significance of benthonic foraminifers and presents correlations based on these data from 16 measured stratigraphic sections and 12 exploratory wells. Relatively few reports employing modern taxonomic methods developed during the past 40 years have been published on foraminiferal biostratigraphy of the Gulf of Alaska. Reports by Cushman (1941), Cushman and Todd (1947), Tappan (1951), Todd (1953), Loeblich and Tappan (1953), Todd (1957), Rau (1963), Cooper (1964), and Todd and Low (1967) are primarily concerned with taxonomy, ecology and paleoecology, or the geologic age of assemblages from isolated outcrops. Almost no data have been published on foraminiferal correlations of measured sections and wells. The paucity of such information has prompted the synthesis and interpretation of foraminiferal data that provide the framework of correlation presented in this report. Some of the benthonic provincial stages that have been assigned to lower and middle parts of the Tertiary of other west coast areas are recognized for the Gulf of Alaska. Divisions for the upper part of the Tertiary are broad, but specific faunal occurrences are recognized as possible aids to correlations. Regional correlations presented in this report are necessarily broad and may be modified and redefined when new data become available from the current round of exploratory drilling for petroleum in the offshore part of the Gulf of Alaska Tertiary Province. It is anticipated that this report will be of particular interest to readers associated with petroleum exploration. As a convenience to them and because most foraminiferal data from wells, including those of this report, are from cuttings, all checklists are arranged to show plainly the highest occurrence of each species within each measured section and well. Furthermore, in conformity with these data, all sections and wells are described from the top to bottom. The text describes the stratigraphic and paleoecologic significance of foraminifers by biostratigraphic units and by individual sections and wells.

Alaska↗

USGS1988

Map of fault scarps formed in unconsolidated sediments, Tooele 1 degree by 2 degrees quadrangle, northwestern Utah

This report is one of a series of studies of western Utah (Anderson and Bucknam, 1979; Bucknam and Anderson, 1979b), eastern Nevada (Barnhard, 1985), and central Nevada (Wallace, 1979) that shows the distribution, relative age, and amount and extent of surface rupture on Quaternary fault scarps. Previous paleoseismicity studies in the Tooele 1°x2° quadrangle include reports by Gilbert (1928), Bucknam (1977), Anderson and Miller (1980), Bucknam and others (1980), and Everitt and Kaliser (1980). Geologic and geophysical data pertinent to paleoseismicity of the Tooele 1°x2° quadrangle can be found in reports by Mikulich and Smith (1974), Cook and others (1980), Smith and Bruhn (1984), and Arabasz and others (1987). The present study is a continuation of mapping fault scarps in 1°x2° quadrangles in the Basin and Range province; the purpose is to determine the youngest surface-faulting age and distribution of fault scarps for earthquake-hazards analysis. The accompanying map shows 10 areas containing late Quaternary fault scarps formed on unconsolidated sediments in the Tooele 1°x2° quadrangle, northwestern Utah. The faulted sediments include sandy, pebbly, to bouldery colluvium, alluvium, and lacustrine deposits. They are inferred to have been deposited in Quaternary time during the latest phase of basin-filling sedimentation. Because the map shows only scarps on unconsolidated sediments, it does not show all faults that could produce earthquakes. A comprehensive map of all Quaternary faults would also include those in bedrock and at the contact of bedrock and alluvium, as well as Quaternary faults that appear only as lineaments in surficial deposits. Initial study involved photointerpretation of high-quality 1:60,000-scale black and white aerial photographs of the map area; offsets as small as 1 m could be detected from these photos if the faults cut planar surfaces of considerable extent. A map of suspected fault scarps, identified from the photointerpretation, was compiled at a scale of 1:250,000 and served as a guide for subsequent field studies in conjunction with a similar map from Bucknam (1977). We have chosen not to connect discontinuous segments of aligned fault scarps unless there is compelling evidence of continuous surface rupture. Field studies consisted of (1) confirming scarps as fault related and deleting from the preliminary map those features that were not fault related or that had no surface offset (lineaments), (2) searching for stratigraphic indicators of amount and age of offset, and (3) measuring surface profiles according to procedures described in Bucknam and Anderson (1979a). We profiled selected fault scarps where they were sufficiently continuous and unmodified by fluvial deposition or erosion. In the early morning or late afternoon when the sun was at 1ow angles, additional field searches were made for scarps resulting from ground ruptures that had not been identified during the photo interpretation phase of the study. No additional scarps were found. Techniques that yield the relative age of fault scarps can be used as a guide to the frequency and location of relatively large earthquakes. For large regions, geologically determined rates of seismic activity in the Basin and Range province are generally in good agreement with rates determined from historic seismicity (Bucknam and Algermissen, 1984). Fault-scarp studies such as this have been used as a guide in locating boundaries of seismic source zones used in probabilistic earthquake hazard estimates of the Basin and Range province (Thenhaus and Wentworth, 1982; Bucknam and Thenhaus, 1983). We will first discuss the geologic setting of the map area and attributes of fault-scarp morphology, and then discuss the individual fault zones.

Utah↗

USGS2005

Summary and preliminary interpretations of USGS cruise A-2-02-HW: Underwater video surveys collected off of Oahu, Molokai, and Maui, Hawaii, June-July 2002

The insular shelves of the southern coasts of the islands of Oahu and Molokai, and the western coast of Maui in the Hawaiian Archipelago were surveyed using ship-towed video between June 26 and July 11, 2002, as part of USGS-CMG cruise A-2-02-HW (Figure 1.1). The goals of the survey were to collect underwater video of the sea floor to: (1) Characterize substrate type and benthic habitat distribution; and (2) Ground-truth recently-acquired data including bathymetric (SHOALS) lidar, side-scan sonar, seismic reflection, and surface texture and grain size. The underwater video also aids in the interpretation and evaluation of Hawaii's benthic habitat maps produced by NOAA and coral reef distribution monitored by the State of Hawaii (Coral Reef Assessment and Monitoring Program - CRAMP; http://cramp.wcc.hawaii.edu/ ). Additional metadata for this cruise is available at: http://walrus.wr.usgs.gov/infobank/a/a202hw/html/a-2-02-hw.meta.html

Hawaii↗

USGS2024

Results of 2018–19 water-quality and hydraulic characterization of aquifer intervals using packer tests and preliminary geophysical-log correlations for selected boreholes at and near the former Naval Air Warfare Center Warminster, Bucks County, Pennsylvania

The U.S. Geological Survey (USGS) collected data on the vertical distribution of hydraulic head, specific capacity, and water quality using aquifer-interval-isolation tests and other vertical profiling methods in 15 boreholes completed in fractured sedimentary bedrock in Northampton, Warminster, and Warwick Townships, Bucks County, Pennsylvania during 2018–19. This work was done, in cooperation with the U.S. Navy, to support detailed investigations at and near the former Naval Air Warfare Center (NAWC) Warminster, where groundwater contamination with per- and polyfluoroalkyl substances (PFAS) had become a concern since 2014. Two PFAS compounds, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), have been measured in groundwater samples from supply and monitoring wells at or near NAWC Warminster in concentrations above U.S. Environmental Protection Agency health advisory levels for drinking water. The area is underlain by the Triassic Stockton Formation, which predominantly consists of sandstone interbedded with shale and siltstone beds and forms a layered fractured-rock aquifer used for private, industrial, and public drinking water supply. The vertical distribution of aquifer properties and water quality was assessed through hydraulic tests and sampling of aquifer intervals using a straddle-packer system (13 boreholes) or depth-discrete point sampling under known borehole-flow conditions (2 boreholes). Geophysical and video logs collected by USGS during 2017–19 were used to identify potential water-bearing fractures in 15 boreholes, which ranged in depth from 210 to 604 feet (ft) and included 6 boreholes drilled in 2018 and 9 existing wells on or near the former NAWC Warminster. Measured borehole flow was predominantly downward in most of the deepest boreholes (greater than 400 ft), which were commonly located at the highest land-surface elevations, with inflow from fractures at relatively shallow depths and outflow through fractures near or below depths of 500 ft below land surface. Hydraulic head differences measured during packer tests were up to about 60 ft between shallow and deep intervals. Borehole flow was predominantly upward in most boreholes less than 400 ft in depth and farther from, and at lower land-surface elevations than, the former NAWC Warminster. Total borehole specific capacity ranged from about 0.07 to 41 gallons per minute per foot [(gal/min)/ft]. Specific-capacity values for individual intervals ranged from 0.02 to 40.0 (gal/min)/ft, with a median of 1.14 (gal/min)/ft and a large range in values at most depths. Differences in water quality of samples as indicated by field properties (pH, dissolved oxygen, and specific conductance) and concentrations of dissolved major ions, PFOA, and PFOS were apparent among isolated intervals in the boreholes. Summed concentrations of PFOA and PFOS ranged from about 11 to 10,780 nanograms per liter (ng/L) and were greater than the 2016 U.S. Environmental Protection Agency health advisory of 70 ng/L for summed PFOA and PFOS concentrations in 62 of 104 intervals and discrete depths tested. The mass ratio of PFOS to PFOA was generally higher than 1.0 in samples with summed PFOA and PFOS concentrations greater than 70 ng/L, with ratio values as high as 8.7. In many boreholes, summed concentrations of PFOA and PFOS were positively related to chloride concentrations, which were elevated above natural-background values [less than 10 milligrams per liter] in most samples and as high as 717 milligrams per liter. Sources of the elevated chloride other than, or in addition to, common rock salt (sodium chloride) were indicated by chloride to sodium molar ratios greater than 1.0. Water-quality data indicated that sampled water from some intervals with lower hydraulic heads may be affected by water from intervals with higher hydraulic heads because of vertical flow in open boreholes; samples from these intervals with lower hydraulic heads may not be fully representative due to some component of cross contamination and should be interpreted with caution. Through a preliminary correlation of natural gamma and resistivity logs of boreholes drilled at and near the former NAWC Warminster, 11 lithologic units were identified and interpreted to strike northeast and dip to the northwest. Hydraulic heads were generally highest in isolated intervals that intercepted beds which, when projected up dip, crop out at the highest land-surface elevation on the former NAWC Warminster, indicating that the dipping-bed structure and topography are factors affecting the distribution of hydraulic head in the aquifer. The hydrogeologic framework in conjunction with the vertical distribution of hydraulic heads and water quality may assist in evaluating the locations of various PFAS sources and potential migration pathways of PFAS in groundwater at and near NAWC Warminster.

Pennsylvania↗

USGS1975

Geology of the Midnite uranium mine, Stevens County, Washington; a preliminary report

The Midnite mine is one of only two mines in the United States currently producing uranium from discordant deposits in crystalline host rocks. Ore bodies are in metamorphosed steeply dipping Precambrian pelitic and calcareous rocks of a roof pendant adjacent to a Cretaceous(?) porphyritic quartz monzonite pluton. Production during 14 years, of operation has been about 8 million pounds of U3O8 from oxidized and reduced ores averaging 0.23 percent U3O8. Uranium deposits are generally tabular in form and dimensions range up to 380 m long, 210 m wide, and 50 m thick. Deposits are bounded on at least one side by unmineralized intrusive ribs of granitic rock, and thickest mineralized zones invariably occur at depressions in the intrusive contact. Upper limits of some deposits are nearly horizontal, and upper elevations of adjacent mineralized zones separated by ribs of granite are similar. Near surface ore is predominantly autunite, but ore at depth consists of pitchblende and coffinite with abundant pyrite and marcasite. Uranium minerals occur as .disseminations along foliation, replacements, and stockwork fracture-fillings. No stratigraphic controls on ore deposition are recognized. Rather, mineralized zones cut across lithologic boundaries if permeability is adequate. Most ore is in muscovite schist and mica phyllite, but important deposits occur in calc-silicate hornfels. Amphibolite sills and mid-Tertiary dacite dikes locally, carry ore where intensely fractured. High content of iron and sulfur, contained chiefly in FeS2, appear to be an important feature of favorable host rocks. Geometry of deposits, structural, and geochemical features suggest that uranium minerals were deposited over a span of time from late Cretaceous to late Tertiary. Ore occurs in but is not offset by a shear zone that displaces mid-Tertiary rocks.. Economic zones of uranium are interpreted to have been secondarily enriched in late Tertiary time by downward and lateral migration of uranium into permeable zones where deposition was influenced by ground water controls and minerals that could reduce or neutralize uranium-bearing solutions.

Open-File Report↗

USGS2017

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi. org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic maps that have been added since the preliminary databases were published. Numerous errors have been corrected and enhancements added to the preliminary datasets using thorough quality assurance/quality control procedures. The SGMC is not a truly integrated geologic map database because geologic units have not been reconciled across State boundaries. However, the geologic data contained in each State geologic map have been standardized to allow spatial analyses of lithology, age, and stratigraphy at a national scale.

Data Series↗

USGS2007

Preliminary physical stratigraphy and geophysical data of the USGS Hope Plantation core (BE-110), Bertie County, North Carolina

In March and April, 2004, the U.S. Geological Survey (USGS), in cooperation with the North Carolina Geological Survey (NCGS) and the Raleigh Water Resources Discipline (WRD), drilled a stratigraphic test hole and well in Bertie County, North Carolina (fig. 1). The Hope Plantation test hole (BE-110-2004) was cored on the property of Hope Plantation near Windsor, North Carolina. The drill site is located on the Republican 7.5 minute quadradrangle at lat 36?01'58'N., long 78?01'09'W. (decimal degrees 36.0329 and 77.0192) (fig. 2). The altitude of the site is 48 ft above mean sea level as determined by Paulin Precise altimeter. This test hole was continuously cored by Eugene F. Cobbs, III and Kevin C. McKinney (USGS) to a total depth of 1094.5 ft. Later, a ground water observation well was installed with a screened interval between 315-329 feet below land surface (fig. 3). Upper Triassic, Lower Cretaceous, Upper Cretaceous, Tertiary, and Quaternary sediments were recovered from the site. The core is stored at the NCGS Coastal Plain core storage facility in Raleigh, North Carolina. In this report, we provide the initial lithostratigraphic summary recorded at the drill site along with site core photographs, data from the geophysical logger, calcareous nannofossil biostratigraphic correlations (Table 1) and initial hydrogeologic interpretations. The lithostratigraphy from this core can be compared to previous investigations of the Elizabethtown corehole, near Elizabethtown, North Carolina in Bladen County (Self-Trail, Wrege, and others, 2004), the Kure Beach corehole, near Wilmington, North Carolina in New Hanover County (Self-Trail, Prowell, and Christopher, 2004), the Esso #1, Esso #2, Mobil #1 and Mobil #2 cores in the Albermarle and Pamlico Sounds (Zarra, 1989), and the Cape Fear River outcrops in Bladen County (Farrell, 1998; Farrell and others, 2001). This core is the third in a series of planned benchmark coreholes that will be used to elucidate the physical stratigraphy, facies, thickness, and hydrogeology of the Tertiary and Cretaceous Coastal Plain sediments of North Carolina.

North Carolina↗

USGS2007

Oxygen isotopes in nitrite: Analysis, calibration, and equilibration

Nitrite is a central intermediate in the nitrogen cycle and can persist in significant concentrations in ocean waters, sediment pore waters, and terrestrial groundwaters. To fully interpret the effect of microbial processes on nitrate (NO 3 - ), nitrite (NO 2 - ), and nitrous oxide (N 2 O) cycling in these systems, the nitrite pool must be accessible to isotopic analysis. Furthermore, because nitrite interferes with most methods of nitrate isotopic analysis, accurate isotopic analysis of nitrite is essential for correct measurement of nitrate isotopes in a sample that contains nitrite. In this study, nitrite salts with varying oxygen isotopic compositions were prepared and calibrated and then used to test the denitrifier method for nitrite oxygen isotopic analysis. The oxygen isotopic fractionation during nitrite reduction to N 2 O by Pseudomonas aureofaciens was lower than for nitrate conversion to N 2 O, while oxygen isotopic exchange between nitrite and water during the reaction was similar. These results enable the extension of the denitrifier method to oxygen isotopic analysis of nitrite (in the absence of nitrate) and correction of nitrate isotopes for the presence of nitrite in “mixed” samples. We tested storage conditions for seawater and freshwater samples that contain nitrite and provide recommendations for accurate oxygen isotopic analysis of nitrite by any method. Finally, we report preliminary results on the equilibrium isotope effect between nitrite and water, which can play an important role in determining the oxygen isotopic value of nitrite where equilibration with water is significant.

Analytical Chemistry↗

USGS2005

Hawaiian Volcano Observatory seismic data, January to December 2004

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M≥1.5 routinely gathered by the Observatory are included. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. Beginning with 2004, summaries will simply be identified by the year, rather than Summary number. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered.

Hawaii↗

USGS1980

Preliminary aeromagnetic map of the Charlotte 1 x 2 degree quadrangle, North Carolina, South Carolina

The aeromagnetic map of the Charlotte 1 x 2 degree quadrangle was assembled by 6 individual detailed aeromagnetic surveys flown between 1956 and 1976 (see index map). The International Geomagnetic Reference Field had been subtracted from the data prior to assembly. An arbitrary common datum was selected and the surveys were recontoured at the joins. The 100 gamma contour was selected because it shows the magnetic contrast to best advantage. To complement the magnetic data a gravity survey was conducted by the U.S. Geological Survey and this data is available in a companion map (Wilson and Daniels, in press). Each of these maps has been interpreted in relation to the other and to the geologic map prepared as part of the same program (Goldsmith and others, 1978). It should be noted that the geophysics has had a measurable influence on some of the geologic mapping.

North Carolina, South Carolina↗

USGS1982

Preliminary geotechnical and geophysical logs from drill hole 2C-80 in the Capps coal field, Cook Inlet region, Alaska

The drilling and logging information provided in this report was collected during September 1980 as part of the Energy Lands program of the U.S. Geological Survey. Drill hole 2C-80 is located in the Capps Coal Field, approximately 100 km (62 mi) west of Anchorage, Alaska (fig. 1). The drilling was undertaken to obtain information on the geotechnical characteristics of a part of the coal-bearing Tyonek Formation and overlying surficial deposits. The preliminary results of a previous drill hole (1C-79), located 1.3 km (0.8 mi) northeast of drill hole 2C-80, were reported by Chleborad and others (1980). The Tyonek Formation is early Oligocene to middle Miocene in age (Wolfe and Tanai, 1980). At the drill site it is overlain by a thin colluvial deposit of Quaternary age. The drilling and continuous core sampling penetrated 19.5 m (63.9 ft) of overburden, a major coal bed (Waterfall bed), and approximately 29 m (95.1 ft) of underlying material, to a total depth of 61 m (200 ft). Drill hole 2C-80 stratigraphically overlaps drill hole 1C-79 and continues down section approximately 33 m (108 ft). A proposed open pit coal-mining plan (Placer Amex, Inc., 1977, status report of December 1977) outlines a sequential mining and reclamation scheme for five areas in the Capps Coal Field. Figure 2 shows the location of drill holes 2C-80 and 1C-79 with respect to the proposed mining areas as well as selected surface features. A general description of the geology and natural hazards of the region are given by Schmoll and others (1981). The generalized lithology interpreted from core obtained from drilling and supplemented by outcrop mapping accomplished during the 1979 and 1980 field seasons is presented in figure 3. A more detailed lithologic log is presented as part of the geotechnical log. The geotechnical and geophysical logs presented herein (pls. 1 and 2) provide basic physical-property and engineering data useful in predicting the response of geologic materials to proposed large-scale coal mining and related development, and in identifying and assessing potential geologic hazards.

Alaska↗