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At least 649 records · Page 36Linked to original sources

Molecular and isotopic compositions of hydrocarbons at Site 533, Deep Sea Drilling Project Leg 76

In an investigation of gas hydrates in deep ocean sediments, gas samples from Deep Sea Drilling Project Site 533 on the Blake Outer Ridge in the northwest Atlantic were obtained for molecular and isotopic analyses. Gas samples were collected from the first successful deployment of a pressure core barrel (PCB) in a hydrate region. The pressure decline curves from two of the four PCB retrievals at in situ pressures suggested the presence of small amounts of gas hydrates. Compositional and isotopic measurements of gases from several points along the pressure decline curve indicated that (1) biogenic methane (δ13C = -68‰; CJ/CJ = 5000) was the dominant gas (>90%); (2) little fractionation in the C,/ C2 ratio or the C carbon isotopic composition occurred as gas hydrates decomposed during pressure decline experi ments; (3) the percent of C3 , i-C4 , and CO2 degassed increased as the pressure declined, indicating that these molecules may help stabilize the hydrate structure; (4) excess nitrogen was present during initial degassing; and (5) Cj/Q ratios and isotopic ratios of C gases were similar to those obtained from conventional core sampling. The PCB gas also con tained trace amounts of saturated, acyclic, cyclic, and aromatic C5 -C14 hydrocarbons, as well as alkenes and tetrahydrothiophenes. Gas from a decomposed specimen of gas hydrate had similar molecular and isotopic ratios to the PCB gas (δ13C of -68% for methane and a q/ Q ratio of -6000). Regular trends in the δ 13C of methane ( 95 60%) and C{ /C2 ratios (-25000 — 2000) were observed with depth. Capillary gas chromatography (GC) and total scanning fluorescence measurements of extracted organic material were characteristic of hydrocarbons dominated by a marine source, though significant amounts of perylene were also present.

Initial Reports of the D.S.D.P.↗

EROS: A space program for Earth resources

Within the technology of the space age lies a key to increased knowledge about the resources and environment of the Earth. This key is remote sensing detecting the nature of an object without actually touching it. Although the photographic camera is the most familiar remote-sensing device, other instrument systems, such as scanning radiometers and radar, also can produce photographs and images. On the basis of the potential of this technology, and in response to the critical need for greater knowledge of the Earth and its resources, the Department of the Interior established the Earth Resources Observation Systems (EROS) Program to gather and use remotely sensed data collected by satellite and aircraft of natural and manmade features on the Earth's surface.

South Dakota↗

National Atlas maps

The National Atlas of the United States of America was published by the U.S. Geological Survey in 1970. Its 765 maps and charts are on 335 14- by 19-inch pages. Many of the maps span facing pages. It's worth a quick trip to the library just to leaf through all 335 pages of this book. Rapid scanning of its thematic maps yields rich insights to the geography of issues of continuing national interest. On most maps, the geographic patterns are still valid, though the data are not current. The atlas is out of print, but many of its maps can be purchased separately. Maps that span facing pages in the atlas are printed on one sheet. The maps dated after 1970 are either revisions of original atlas maps, or new maps published in atlas format. The titles of the separate maps are listed here.

Monograph↗

Upper Klamath Basin Landsat Image for June 24, 2006: Path 44 Row 31

This subset of a Landsat-7 image shows part of the upper Klamath Basin. The original images were obtained from the U.S. Geological Survey Earth Resources Observation and Science Center (EROS). EROS is responsible for archive management and distribution of Landsat data products. The Landsat-7 satellite is part of an ongoing mission to provide quality remote sensing data in support of research and applications activities. The launch of Landsat-7 on April 15, 1999 marks the addition of the latest satellite to the Landsat series. The Landsat-7 satellite carries the Enhanced Thematic Mapper Plus (ETM+) sensor. A mechanical failure of the ETM+ Scan Line Corrector (SLC) occurred on May 31, 2003, with the result that all Landsat 7 scenes acquired from July 14, 2003 to present have been collected in 'SLC-off' mode. More information on the Landsat program can be found online at http://landsat.usgs.gov/.

Oregon↗

Upper Klamath Basin Landsat Image for July 10, 2006: Path 44 Row 31

This subset of a Landsat-7 image shows part of the upper Klamath Basin. The original images were obtained from the U.S. Geological Survey Earth Resources Observation and Science Center (EROS). EROS is responsible for archive management and distribution of Landsat data products. The Landsat-7 satellite is part of an ongoing mission to provide quality remote sensing data in support of research and applications activities. The launch of Landsat-7 on April 15, 1999 marks the addition of the latest satellite to the Landsat series. The Landsat-7 satellite carries the Enhanced Thematic Mapper Plus (ETM+) sensor. A mechanical failure of the ETM+ Scan Line Corrector (SLC) occurred on May 31, 2003, with the result that all Landsat 7 scenes acquired from July 14, 2003 to present have been collected in 'SLC-off' mode. More information on the Landsat program can be found online at http://landsat.usgs.gov/.

Oregon↗

Upper Klamath Basin Landsat Image for April 28, 2006: Path 45 Rows 30 and 31

This image is a mosaic of Landsat-7 images of the upper Klamath Basin. The original images were obtained from the U.S. Geological Survey Earth Resources Observation and Science Center (EROS). EROS is responsible for archive management and distribution of Landsat data products. The Landsat-7 satellite is part of an ongoing mission to provide quality remote sensing data in support of research and applications activities. The launch of Landsat-7 on April 15, 1999 marks the addition of the latest satellite to the Landsat series. The Landsat-7 satellite carries the Enhanced Thematic Mapper Plus (ETM+) sensor. A mechanical failure of the ETM+ Scan Line Corrector (SLC) occurred on May 31, 2003, with the result that all Landsat 7 scenes acquired from July 14, 2003 to present have been collected in 'SLC-off' mode. More information on the Landsat program can be found online at http://landsat.usgs.gov/.

Oregon↗

Upper Klamath Basin Landsat Image for May 30, 2006: Path 45 Rows 30 and 31

This image is a mosaic of Landsat-7 images of the upper Klamath Basin. The original images were obtained from the U.S. Geological Survey Earth Resources Observation and Science Center (EROS). EROS is responsible for archive management and distribution of Landsat data products. The Landsat-7 satellite is part of an ongoing mission to provide quality remote sensing data in support of research and applications activities. The launch of Landsat-7 on April 15, 1999 marks the addition of the latest satellite to the Landsat series. The Landsat-7 satellite carries the Enhanced Thematic Mapper Plus (ETM+) sensor. A mechanical failure of the ETM+ Scan Line Corrector (SLC) occurred on May 31, 2003, with the result that all Landsat 7 scenes acquired from July 14, 2003 to present have been collected in 'SLC-off' mode. More information on the Landsat program can be found online at http://landsat.usgs.gov/.

Oregon↗

Seafloor images refine petroleum exploration models

Acoustic mapping of the EEZ sea floor using GLORIA side-scan sonar tool includes the margins of the continental United States, Alaska, Hawaii, and Johnston Island. This decade-long program was undertaken in cooperation with the United Kingdom's Institute of Oceanographic Sciences at the Deacon Laboratory (now the Southampton Oceanography Centre).

Report↗

Use of remote-sensing techniques to survey the physical habitat of large rivers

Remote-sensing techniques that can be used to quantitatively characterize the physical habitat in large rivers in the United States where traditional survey approaches typically used in small- and medium-sized streams and rivers would be ineffective or impossible to apply. The state-of-the-art remote-sensing technologies that we discuss here include side-scan sonar, RoxAnn, acoustic Doppler current profiler, remotely operated vehicles and camera systems, global positioning systems, and laser level survey systems. The use of these technologies will permit the collection of information needed to create computer visualizations and hard copy maps and generate quantitative databases that can be used in real-time mode in the field to characterize the physical habitat at a study location of interest and to guide the distribution of sampling effort needed to address other habitat-related study objectives. This report augments habitat sampling and characterization guidance provided by Meador et al. (1993) and is intended for use primarily by U.S. Geological Survey National Water Quality Assessment program managers and scientists who are documenting water quality in streams and rivers of the United States.

Report↗

Characterization of the Hosgri Fault Zone and adjacent structures in the offshore Santa Maria Basin, south-central California

The Hosgri Fault Zone trends subparallel to the south-central California coast for 110 km from north of Point Estero to south of Purisima Point and forms the eastern margin of the present offshore Santa Maria Basin. Knowledge of the attributes of the Hosgri Fault Zone is important for petroleum development, seismic engineering, and environmental planning in the region. Because it lies offshore along its entire reach, our characterizations of the Hosgri Fault Zone and adjacent structures are primarily based on the analysis of over 10,000 km of common-depth-point marine seismic reflection data collected from a 5,000-km2 area of the central and eastern parts of the offshore Santa Maria Basin. We describe and illustrate the along-strike and downdip geometry of the Hosgri Fault Zone over its entire length and provide examples of interpreted seismic reflection records and a map of the structural trends of the fault zone and adjacent structures in the eastern offshore Santa Maria Basin. The seismic data are integrated with offshore well and seafloor geologic data to describe the age and seismic appearance of offshore geologic units and marker horizons. We develop a basin-wide seismic velocity model for depth conversions and map three major unconformities along the eastern offshore Santa Maria Basin. Accompanying plates include maps that are also presented as figures in the report. Appendix A provides microfossil data from selected wells and appendix B includes uninterpreted copies of the annotated seismic record sections illustrated in the chapter. Features of the Hosgri Fault Zone documented in this investigation are suggestive of both lateral and reverse slip. Characteristics indicative of lateral slip include (1) the linear to curvilinear character of the mapped trace of the fault zone, (2) changes in structural trend along and across the fault zone that diminish in magnitude toward the ends of the fault zone, (3) localized compressional and extensional structures characteristic of constraining and releasing bends and stepovers, (4) changes in the sense and magnitude of vertical separation along strike within the fault zone, and (5) changes in downdip geometry between the major traces and segments of the fault zone. Characteristics indicative of reverse slip include (1) reverse fault geometries that occur across major strands of the fault zone and (2) fault-bend folds and localized thrust faults that occur along the northern and southern reaches of the fault. Analyses of high-resolution, subbottom profiler and side-scan sonar records indicate localized Holocene activity along most of the extent of the fault zone. Collectively, these features are the basis of our characterization of the Hosgri Fault Zone as an active, 110-km-long, convergent right-oblique slip (transpressional) fault with identified northern and southern terminations. This interpretation is consistent with recently published analyses of onshore geologic data, regional tectonic kinematic models, and instrumental seismicity.

California↗

Tufts submarine fan: turbidity-current gateway to Escanaba Trough

Turbidity-current overflow from Cascadia Channel near its western exit from the Blanco Fracture Zone has formed the Tufts submarine fan, which extends more than 350 km south on the Pacific Plate to the Mendocino Fracture Zone. For this study, available 3.5-kHz high-resolution and airgun seismic-reflection data, long-range side-scan sonar images, and sediment core data are used to define the growth pattern of the fan. Tufts fan deposits have smoothed and filled in the linear ridge-and-valley relief over an area exceeding 23,000 km2 on the west flank of the Gorda Ridge. The southernmost part of the fan is represented by a thick (as much as 500 m) sequence of turbidite deposits ponded along more than 100 km of the northern flank of the Mendocino Fracture Zone. Growth of the Tufts fan now permits turbidity-current overflow from Cascadia Channel to reach the Escanaba Trough, a deep rift valley along the southern axis of the Gorda Ridge. Scientific drilling during both the Deep Sea Drilling Project (DSDP) and the Ocean Drilling Program (ODP) provided evidence that the 500-m-thick sediment fill of Escanaba Trough is dominantly sandy turbidites. Radiocarbon dating of the sediment at ODP Site 1037 showed that deposition of most of the upper 120 m of fill was coincident with Lake Missoula floods and that the provenance of the fill is from the eastern Columbia River drainage basin. The Lake Missoula flood discharge with its entrained sediment continued flowing downslope upon reaching the ocean as hyperpycnally generated turbidity currents. These huge turbidity currents followed the Cascadia Channel to reach the Pacific Plate, where overbank flow provided a significant volume of sediment on Tufts fan and in Escanaba Trough. Tufts fan and Tufts Abyssal Plain to the west probably received turbidite sediment from the Cascadia margin during much of the Pleistocene.

Escanaba Trough↗

Interlaboratory comparison of mineral constituents in a sample from the Herrin (No. 6) coal bed from Illinois

Approximately 20 kg of the Herrin (No. 6) coal was collected from a strip mine in St. Clair County, Ill. A 10-kg portion was ground to -60 mesh, homogenized, and riffled into 128 splits of 70-80 g each. Homogeneity of these splits was confirmed by moisture, ash, and sulfur analyses of six randomly selected splits. Results of these analyses were within the ASTM (American Society for Testing and Materials) guidelines for interlaboratory precision. Splits of the Herrin (No. 6) coal were then transmitted to more than 30 laboratories for analysis. Low-temperature plasma oxidation was used to isolate inorganic matter for quantitative chemical and mineralogical analysis. Despite a wide variation in ashing conditions, only minor variations in ash yields were obtained; these variations were attributed to differences in operating temperature and moisture content. Mineralogical analyses of low-temperature ash (LTA) concentrates prepared by five different laboratories indicated variations within the limits of analytical error. The mean values, in weight percent, for the major minerals are as follows: calcite, 9; quartz, 20; pyrite, 23; kaolinite, 14; and illite+mixed-layer clays, 31. Normative mineralogical calculations and Fourier transform infrared analysis (FTIR) yielded results similar to those obtained from X-ray diffraction (XRD). Choosing appropriate mineral standards was found to be critical for the proper use of analytical techniques such as XRD and FTIR. Good interlaboratory agreement was obtained for most major, minor, and trace elements despite differences in analytical procedures and in the type of sample analyzed (coal, high-temperature ash, or LTA). Discrepancies between analyses for zinc, strontium, manganese, and iron may be attributed to sampling inhomogeneity problems. Mossbauer spectroscopy showed that approximately 44 percent of the pyritic sulfur was lost through weathering in the first year after preparation of the interlaboratory sample. Szomolnokite and possibly coquimbite and jarosite were also identified. Scanning electron microscopy studies indicated ubiquitous pyrite framboids and, less commonly, euhedral crystals, skeletal grains, irregularly shaped particles, and vein fillings. Minor accessory minerals such as rare-earth phosphates and possibly silicates, zircon, barium sulfate, titanium oxide, and sphalerite were also found. The textural evidence indicates that the minerals in the banded material are detrital whereas the minerals occurring as vein and pore fillings are authigenic. Magnetic measurements indicate that coal crushed in a steel pulverizer is contaminated by small quantities of abrasion fragments from the crusher, which seriously affect the measured magnetic properties of the coal.

Circular↗

Archive of bathymetry and backscatter data collected in 2014 nearshore Breton and Gosier Islands, Breton National Wildlife Refuge, Louisiana

As part of the Barrier Island Monitoring Project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off Breton and Gosier Islands, Louisiana, in July and August of 2014. To assist the United States Fish and Wildlife Service (USFWS) with restoration planning efforts, the USGS was tasked with answering fundamental questions about the physical environment of the southern Chandeleur Islands, including the geology, morphology, and oceanography. Baseline data needed to answer these questions were either insufficient or missing. The USGS conducted a comprehensive geologic investigation in the summer of 2014, collecting geophysical and sedimentological data. Breton Island, located at the southern end of the Chandeleur Island chain in southeastern Louisiana, was recognized as a natural, globally significant nesting sanctuary for several bird species and was established as the Breton National Wildlife Refuge (NWR) in 1904. The areal extent of Breton Island has diminished 90 percent since 1920. Land loss is attributed to ongoing relative sea-level rise, diminished sediment supply, and storm impacts. The bird population on Breton Island has also declined over the years, most notably after Hurricane George in 1998 and after Hurricane Katrina in 2015; the latter completely submerged the island. Despite decreasing habitable acreage, migratory seabirds continue to return and nest on Breton Island. To prevent the island from being submerged in the future, and to protect, stabilize, and provide more nesting and foraging areas for the bird population, the USFWS proposed a restoration effort to rebuild Breton Island to its pre-Katrina footprint. This data series serves as an archive of processed interferometric swath and single-beam bathymetry data, and side-scan sonar data, collected in the nearshore of Breton and Gosier Islands, NWR, Louisiana. The data were collected during two USGS cruises (USGS Field Activity Numbers 2014-314-FA and 2014-317-FA) in July and August 2014. Geographic information system data products include a 100-meter-cell-size interpolated bathymetry grid, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata. NOTE: These data are scientific in nature and are not to be used for navigation. Any use of trade names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Louisiana↗

Digital data to support development of a pesticide management plan for the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota

As part of a program to support development of pesticide management plans for Indian Reservations, the U.S. Geological Survey has been working in cooperation with the U.S. Environmental Protection Agency to make selected information available to the Tribes or in a format easier for the Tribes to use. As a result of this program, four digital data sets related to the geology or hydrology of the Standing Rock Indian Reservation were produced as part of this report. The digital data sets are based on maps published in 1982 at the 1:250,000 scale in "Geohydrology of the Standing Rock Indian Reservation, North and South Dakota," U.S. Geological Survey Hydrologic Investigations Atlas HA-644 by L.W. Howells. The digital data sets were created by 1) scanning the appropriate map to create an image file, 2) registering the image file to real-world coordinates, 3) creating a new image file rectified to real-world coordinates, and 4) digitizing of the features of interest using the rectified image as a guide. As digital data sets, the information can be used in a geographic information system in combination with other information to help develop a pesticide management plan.

Data Series↗

Database for geologic maps of pyroclastic-flow and related deposits of the 1980 eruptions of Mount St. Helens, Washington

This publication releases digital versions of the geologic maps in U.S. Geological Survey Miscellaneous Investigations Map 1950 (USGS I-1950), “Geologic maps of pyroclastic-flow and related deposits of the 1980 eruptions of Mount St. Helens, Washington” (Kuntz, Rowley, and MacLeod, 1990) ( https://pubs.er.usgs.gov/publication/i1950 ). The 1980 Mount St. Helens eruptions on May 18, May 25, June 12, July 22, August 7, and October 16–18 produced pyroclastic-flow and related deposits. The distribution and morphology of these deposits, as determined from extensive field studies and examination of vertical aerial photographs, are shown on four maps in I-1950 (maps A–D) on two map sheets. Map A shows the May 18, May 25, and June 12 deposits; map B shows the July 22 deposits; map C shows the August 7 deposits; and map D shows the October 16–18 deposits. No digital geospatial versions of the geologic data were made available at the time of publication of the original maps. This data release consists of attributed vector features, data tables, and the cropped and georeferenced scans from which the features were digitized, in order to enable visualization and analysis of these data in GIS software. This data release enables users to digitally re-create the maps and description of map units of USGS I-1950; map sheet 1 includes text sections (Introduction, Physiography of Mount St. Helens at the time of the 1980 eruptions, Processes of the 1980 eruptions, Deposits of the 1980 eruptions, Limitations of the maps, Preparation of the maps, and References cited) and associated tables and figures that are not included in this data release.

Washington↗

Rectified images of selected geologic maps in the Northern Rockies Area, Idaho, Montana, Washington, and Wyoming

Selected geologic maps covering parts of the Northern Rocky Mountains and adjacent areas were converted to raster images and georeferenced (rectified) for use in a geographic information system (GIS). These rectified images were created for the purpose of visually comparing published geologic maps with other geospatial information. However, they cannot be queried or used for spatial analysis thus limiting their use in a GIS. The 42 georeferenced images included in this report range in scale from 1:250,000 to 1:100,000.Tagged Image Format (TIFF) images of the maps were generated by scanning an original paper map or converting previously published Portable Document Format (PDF) images or Encapsulated Post-Script (EPS) files. To reduce file size and minimize image overlap, the TIFF images were cropped, and then rectified using ArcMap? 8 and converted to MrSID? images. Information in the explanation and cross sections can be viewed in un-rectified images of the original publications that are included with this report. In addition, the text in the map unit description along with the unit name, map label, and a citation are organized in a searchable PDF file.

Data Series↗

Geologic Map Database of Texas

The purpose of this report is to release a digital geologic map database for the State of Texas. This database was compiled for the U.S. Geological Survey (USGS) Minerals Program, National Surveys and Analysis Project, whose goal is a nationwide assemblage of geologic, geochemical, geophysical, and other data. This release makes the geologic data from the Geologic Map of Texas available in digital format. Original clear film positives provided by the Texas Bureau of Economic Geology were photographically enlarged onto Mylar film. These films were scanned, georeferenced, digitized, and attributed by Geologic Data Systems (GDS), Inc., Denver, Colorado. Project oversight and quality control was the responsibility of the U.S. Geological Survey. ESRI ArcInfo coverages, AMLs, and shapefiles are provided.

Data Series↗

Earth science photographs from the U.S. Geological Survey Library

This CD-ROM set contains 1,500 scanned photographs from the U.S. Geological Survey Library for use as a photographic glossary of elementary geologic terms. Scholars are encouraged to copy these public domain images into their reports or databases to enhance their presentations. High-quality prints and (or) slides are available upon request from the library. This CD-ROM was produced in accordance with the ISO 9660 standard; however, it is intended for use on DOS-based computer systems only.

Data Series↗