Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Preliminary Interpretive Reports”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
USGS1952

Stratigraphic sections of the Phosphoria formation in Wyoming, 1947-48

As part of a comprehensive investigation of the phosphate deposits of the western field begun in 1947, the U. S. Geological Survey has measured and sampled the Permian Phosphoria formation at many localities in Wyoming and adjacent states. Because these data will not be fully synthesized for many years, segments of the data, accompanied by little or no interpretation, will be published as preliminary reports as they are assembled. This report, which contains abstracts of some of the sections measured in western Wyoming (pl. 1), is one of this series. The field and laboratory procedures adopted in these investigations are described rather fully in a companion report (McKelvey and others, 1952a). Many people have taken part in this investigation. R. M. Campbell, R. A. Gulbrandsen, R. A. Harris, D. M. Larrabee, F. W. O'Malley, O. A. Payne, R. S. Sears, R. P. Sheldon, and R. A. Smart participated in the description of the strata and the collection of the samples referred to in this report. D. B. Dimick, H. A. Larsen, and T. K. Rigby assisted in the preparation of exposures and the crushing and splitting of samples in the field. The laboratory preparation of samples for chemical analysis was done in Denver, Colo., under the direction of W. P. Huleatt. Most of the P 2 O 5 and acid-insoluble analyses were made for the Survey by the U. S. Bureau of Mines at the Northwest Electrodevelopment Laboratory, Albany, Oreg., under the direction of S. M. Shelton and M. L. Wright. Most of the Al 2 O 3 , Fe 2 O 3 , and loss-on-ignition analyses were made by the Trace Elements Section laboratory of the Survey in Washington, D. C., under the direction of J. C. Rabbitt by chemists I. Barlow, A. Caemmerer, J. Greene, F. S. Grimadli, N. Guttag, H. Levine, H. Mela, Jr., and R. G. Milkey, and most of the spectrographic reports were prepared in this laboratory by C. L. Waring. The samples from one locality (Coal Canyon) were analyzed for P 2 O 5 , Al 2 O 3 , Fe 2 O 3 , V 2 O 5 , F, loss on ignition, and acid insoluble in the Chemical Laboratory of the Tennessee Valley Authority at Wilson Dam, Alabama, and spectrographically by D. M. Mortimer, of the Bureau of Mines at Albany. Compilation of the data has been largely by R. P. Sheldon and F. D. Frieske under the supervision of R. W. Swanson. Organization of the tabular data has been largely by Anita Cozzetto.

Wyoming↗
USGS1952

Stratigraphic sections of the Phosphoria formation in Utah, 1947-48

As part of a comprehensive investigation of the phosphate deposits of the western field begun in 1947, the U. S. Geological survey has measured an sampled the full thickness of the Permian Phosphoria formation and its partial correlative, the Park City formation, at many localities in Utah and other western states. Although these data will not be fully analyzed for several years, segments of the data, accompanied by little or no interpretation, will be published as preliminary reports. This report, which contains abstracts of many of the sections measured in northeastern Utah (pl. 1), is one of this series. The field and laboratory procedures adopted in these investigations are described rather fully in a companion report (McKelvey and others, 1952). A large number of people have taken part in this investigation. J. B. Collins, R. A. Gulbrandsen, R. A. Hoppin, J. A. Noel, F. W. O'Malley, O. A. Payne, J. F. Rominger, R. P. Sheldon, J. E. Smedley, and R. G. Waring participated in the description of strata and collection of samples referred to in this report. D. B. Dimick, H. A. Larsen, and T. K. Rigby assisted in the preparation of trenches and the crushing and splitting of samples in the field. The laboratory preparation of samples for chemical analysis was done in Denver, Colo., under the direction of W. P. Huleatt. Most of the chemical analyses reported herein were made for the Survey by the U. S. Bureau of Mines at the Northwest Electrodevelopment Laboratory, Albany, Oreg., under the direction of S. M. Shelton and M. L. Wright. All the samples from one locality (Brazer Canyon) were analyzed in the Chemical Laboratory of the Tennessee Valley Authority at Wilson Dam, Ala. Some of the Al 2 O 3 , Fe 2 O 3 , and loss-on-ignition analyses were made in the Trace Elements Section laboratory of the Survey in Washington, D. C., under the direction of J. C. Rabbitt by chemists I. Barlow, A Caemmerer, J. Greene, N. Guttag, and E. H. Humphrey. The spectrographic analyses were made by D. M. Mortimer, of the Bureau of Mines in Albany. Compilation of the data has been largely by R. P. Sheldon and F. D. Frieske under the supervision of R. W. Swanson. Organization of the tabular data has been largely by Anita Cozzetto.

Utah↗
USGS1952

Stratigraphic sections of the Phosphoria in Montana, 1947-48

The U. S. Geological Survey has recently measured and sampled the Phosphoria formation at many localities in Montana and other western states. These data will not be fully synthesized and analyzed for several years, but segments of the data, accompanied by little or no interpretation, will be published as preliminary reports as they are assembled. This report, which contains abstracts of many of the sections measured in southwestern Montana (pl. 1), is one of this series. The field and laboratory procedures adopted in these investigations are described rather fully in a companion report (McKelvey and others, 1952). Many people have taken part in this investigation. The program of which this work is a part was organized by V. E. McKelvey. J. G. Evans, J. E. Joyce, J. A. Kelleher, R. L. Konizeski, J. A. Mann, R. L. Parker, J. E Smedley, L. A. Thomas, and W. H. Wilson participated in the description of strata and collection of samples referred to in this report. The laboratory preparation of samples for chemical analysis was done in Denver, Colo., under the direction of W. P. Huleatt. All the P 2 O 5 , F, V 2 O 5 , and acid-insoluble analyses were made for the Survey by the U. S. Bureau of Mines at the Northwest Electrodevelopment Laboratory, Albany, Oreg., under the direction of S. M. Shelton and M. L. Wright. The Al 2 O 3 , Fe 2 O 3 , and loss-on-ignition analyses were about equally distributed between the Bureau of Mines and the Trace Elements Section laboratory of the Survey in Washington, D. C., under the direction of J. C. Rabbit by chemists I. Barlow, A. Caemmerer, J. Greene, N. Guttag, and E. H. Humphrey. The spectrographic analyses were made by D. M. Mortimer, of the Bureau Mines in Albany, and the oil-shale analyses were made by the Bureau of Mines Petroleum and Oil-Shale Experiment Station at Laramie, Wyo. Compilation of the data has been largely by R. P. Sheldon and F. D. Frieske. Organization of the tabular data has been largely by Anita Cozzetto.

Montana↗
USGS1992

Text and References To Accompany "Map Showing the Thickness and Character of Quaternary Sediments in the Glaciated United States East of the Rocky Mountains"

A 1:1,000,000-scale map of Quaternary deposits has been compiled for the glaciated area of the United States east of the Rocky Mountains (that is, the area covered by the Laurentide ice sheets). Parts of southern Ontario, areas beneath the Great Lakes, and parts of the submerged eastern seaboard are also included on the map. The map has three components that, together, provide the first regional three-dimensional view of these deposits. These map components are the surface distribution of Quaternary sediments, the total thickness of Quaternary sediments, and the distribution of significant buried Quaternary units. For many areas, this is the first map of Quaternary sediment thickness published at any scale. This report provides supporting information for the map, preliminary interpretations of sediment distribution, and the list of geologic sources used to generate the map. Within the mapped area, there is a particular need for three-dimensional geologic mapping to support decisions on water resources and land use. Approximately 40 percent of the U.S. population resides within the mapped area, which is less than one-quarter the size of the conterminous United States. This map is intended to supplement the more detailed mapping on which it is based and is designed to be a regional planning tool. Through the Pleistocene, large deposits of thick glacial sediment accumulated between certain late Wisconsinan glacial lobes, on bedrock topographic highs, whereas relatively thin deposits generally accumulated in the adjacent bedrock lowlands occupied by drainage and ice lobes. The lithology of the bedrock and its resistance to erosion in part controlled the patterns of ice lobation and the distribution of thick sediment. On a local scale, the spatial relation of these sediment masses to ice lobation has been suggested in places, and a regional correlation may have been assumed. This map provides the first comprehensive, regional view of glacial sediment thickness to permit such a correlation to be assessed.

Bulletin↗
USGS2000

Preliminary report on geophysics of the Verde River headwaters region, Arizona

This report summarizes the acquisition, data processing, and preliminary interpretation of a high-resolution aeromagnetic and radiometric survey near the confluence of the Big and Little Chino basins in the headwaters of the Verde River, Arizona. The goal of the aeromagnetic study is to improve understanding of the geologic framework as it affects groundwater flow, particularly in relation to the occurrence of springs in the upper Verde River headwaters region. Radiometric data were also collected to map surficial rocks and soils, thus aiding geologic mapping of the basin fill. Additional gravity data were collected to enhance existing coverage. Both aeromagnetic and gravity data indicate a large gradient along the Big Chino fault, a fault with Quaternary movement. Filtered aeromagnetic data show other possible faults within the basin fill and areas where volcanic rocks are shallowly buried. Gravity lows associated with Big Chino and Williamson Valleys indicate potentially significant accumulations of low-density basin fill. The absence of a gravity low associated with Little Chino Valley indicates that high-density rocks are shallow. The radiometric maps show higher radioactivity associated with the Tertiary latites and with the sediments derived from them. The surficial materials on the eastern side of the Big Chino Valley are significantly lower in radioactivity and reflect the materials derived from the limestone and basalt east of the valley. The dividing line between the low radioactivity materials to the east and the higher radioactiviy materials to the west coincides approximately with the major drainage system of the valley, locally known as Big Chino Wash. This feature is remarkably straight and is approximately parallel to the Big Chino Fault. The uranium map shows large areas with concentrations greater than 5 ppm eU, and we expect that these areas will have a significantly higher risk potential for indoor radon.

Arizona↗
USGS2006

Geophysical studies of the Crump Geyser known geothermal resource area, Oregon, in 1975

The U.S. Geological Survey (USGS) conducted geophysical studies in support of the resource appraisal of the Crump Geyser Known Geothermal Resource Area (KGRA). This area was designated as a KGRA by the USGS, and this designation became effective on December 24, 1970. The land classification standards for a KGRA were established by the Geothermal Steam Act of 1970 (Public Law 91-581). Federal lands so classified required competitive leasing for the development of geothermal resources. The author presented an administrative report of USGS geophysical studies entitled 'Geophysical background of the Crump Geyser area, Oregon, KGRA' to a USGS resource committee on June 17, 1975. This report, which essentially was a description of geophysical data and a preliminary interpretation without discussion of resource appraisal, is in Appendix 1. Reduction of sheets or plates in the original administrative report to page-size figures, which are listed and appended to the back of the text in Appendix 1, did not seem to significantly degrade legibility. Bold print in the text indicates where minor changes were made. A colored page-size index and tectonic map, which also show regional geology not shown in figure 2, was substituted for original figure 1. Detailed descriptions for the geologic units referenced in the text and shown on figures 1 and 2 were separately defined by Walker and Repenning (1965) and presumably were discussed in other reports to the committee. Heavy dashed lines on figures 1 and 2 indicate the approximate KGRA boundary. One of the principal results of the geophysical studies was to obtain a gravity map (Appendix 1, fig. 10; Plouff, and Conradi, 1975, pl. 9), which reflects the fault-bounded steepness of the west edge of sediments and locates the maximum thickness of valley sediments at about 10 kilometers south of Crump Geyser. Based on the indicated regional-gravity profile and density-contrast assumptions for the two-dimensional profile, the maximum sediment thickness was estimated at 820 meters. A three-dimensional gravity model would have yielded a greater thickness. Audiomagnotelluric measurements were not made as far south as the location of the gravity low, as determined in the field, due to a lack of communication at that time. A boat was borrowed to collect gravity measurements along the edge of Crump Lake, but the attempt was curtailed by harsh, snowy weather on May 21, 1975, which shortly followed days of hot temperature. Most of the geophysical data and illustrations in Appendix 1 have been published (Gregory and Martinez, 1975; Plouff, 1975; and Plouff and Conradi, 1975), and Donald Plouff (1986) discussed a gravity interpretation of Warner Valley at the Fall 1986 American Geophysical Union meeting in San Francisco. Further interpretation of possible subsurface geologic sources of geophysical anomalies was not discussed in Appendix 1. For example, how were apparent resistivity lows (Appendix 1, figs. 3-6) centered near Crump Geyser affected by a well and other manmade electrically conductive or magnetic objects? What is the geologic significance of the 15-milligal eastward decrease across Warner Valley? The explanation that the two-dimensional gravity model (Appendix 1, fig. 14) was based on an inverse iterative method suggested by Bott (1960) was not included. Inasmuch as there was no local subsurface rock density distribution information to further constrain the gravity model, the three-dimensional methodology suggested by Plouff (1976) was not attempted. Inasmuch as the associated publication by Plouff (1975), which released the gravity data, is difficult to obtain and not in digital format, that report is reproduced in Appendix 2. Two figures of the publication are appended to the back of the text. A later formula for the theoretical value of gravity for the given latitudes at sea level (International Association of Geodesy, 1971) should be used to re-compute gravity anomalies. To merge t

Open-File Report↗
USGS1952

Stratigraphic sections of the Phosphoria formation in Idaho, 1947-48, Part I

The Permian Phosphoria formation of the western states contains one of the world's largest reserves of phosphate. Although previous investigations (see especially Mansfield, 1927), including reconnaissance geologic mapping and sampling, established the location of most of the important deposits and their quality of scattered localities, they were not sufficiently detailed to permit a comparison of the merits of individual deposits or an appraisal of the reserves of phosphate rock that might be available under present economic conditions. Because the growing importance of the western phosphate deposits requires a better, more detailed understanding of their distribution and quality, the Geological Survey began in 1947 a comprehensive investigation, including (1) reconnaissance geologic mapping, mostly in Montana, of areas in which the Phosphoria formation could occur but where it had not previously been looked for or found; (2) geologic mapping, mostly in Montana, at a scale no smaller than 1:62,500, of several areas known to contain the Phosphoria formation but not previously mapped except in reconnaissance fashion; (3) geologic and topographic mapping, at a scale of 1:12,000, of some of the richest, thickest, and most accessible deposits; (4) measuring, describing, and sampling all beds of the phosphatic and shaly parts, and in some places the full thickness, of the Phosphoria formation and its stratigraphic equivalents at one or two localities per township over the entire field; (5) chemical and spectrographic analysis of the samples for phosphate, fluorine, minor metals, oil, and rock-forming constituents; and (6) petrologic and geochemical studies of the rocks and minerals of the formation. These studies are designed to define the regional and local geologic structures in which the phosphate bed lie, to provide a basis for the estimation of reserves of the inferred class over the entire region, and to determine the origin of the rocks and the elements contained in them. The data collected are not of the detail required to plan actual mining operations, but it is hoped they will guide industry in the selection of individual deposits worthy of further exploration. Most of the field work contemplated as a part of this investigation is now completed. Although the data will not be compiled or published in final form for some years to come, segments of the data, accompanied by little or no interpretation, will be published as preliminary maps or reports as they are assembled. The present report is the first of a series presenting in abbreviated form the description and analyses of the beds measured and sampled at various localities in southeastern Idaho (pl. 1). Companion reports presenting segments of the data from Montana, Wyoming, and Utah (Swanson and others, 1952, and McKelvey and others, 1952a and 1952b) are being released at the same time as this report, and others are in preparation.

Idaho↗
USGS1986

Compilation and preliminary interpretation of hydrologic data for the Weldon Spring radioactive waste-disposal sites, St Charles County, Missouri — A progress report

The Weldon Spring Chemical Plant is located just north of the drainage divide separating the Mississippi River and the Missouri River in St. Charles County, Missouri. From 1957 to 1966 the plant converted uranium-ore concentrates and recycled scrap to pure uranium trioxide, uranium tetrafluoride, and uranium metal. Residues from these operations were pumped to four large pits that had been excavated near the plant. Small springs and losing streams are present in the area. Water overlying the residue in the pits has a large concentration of dissolved solids and a different chemical composition compared to the native groundwater and surface water. This difference is indicated by the concentrations of calcium, sodium, sulfate, nitrate, fluoride, uranium, radium, lithium, molybdenum, strontium, and vanadium, all of which are greater than natural or background concentrations. Water from Burgermeister Spring, located about 1.5 miles north of the chemical plant area, contains uranium and nitrate concentrations greater than background concentrations. Groundwater in the shallow bedrock aquifer moves northward from the vicinity of the chemical plant toward Dardenne Creek. An abandoned limestone quarry several miles southwest of the chemical plant also has been used for the disposal of radioactive waste and rubble. Groundwater flow from the quarry area is southward through the alluvium, away from the quarry and toward the Missouri River. The St. Charles County well field is located in the Missouri River flood plain near the quarry and the large yield wells are open to the Missouri River alluvial aquifer. Water from a well 4,000 ft southeast of the quarry was analyzed; there was no indication of contamination from the quarry. Additional water quality and water level data are needed to determine if water from the quarry moves toward the well field. Observation wells need to be installed in the area between the chemical plant, pits, and Dardenne Creek. The wells would be used to provide access for measurements of depth to ground water and for the collection of water samples from the shallow bedrock aquifer.

Missouri↗
USGS1967

Preliminary report on the geology, geophysics and hydrology of USBM/AEC Colorado core hole No. 2, Piceance Creek Basin, Rio Blanco County, Colorado

Approximately 1,400 feet of continuous core was taken .between 800-2,214 feet in depth from USBM/AEC Colorado core hole No. 2. The drill, site is located in the Piceance Creek basin, Rio Blanco County, Colorado. From ground surface the drill hole penetrated 1,120 feet of the Evacuation Creek Member and 1,094 feet of oil shale in the Parachute Creek Member of the Green River Formation. Oil shale yielding more than 20 gallons per ton occurs between 1,260-2,214 feet in depth. A gas explosion near the bottom of the hole resulted in abandonment of the exploratory hole which was still in oil shale. The top of the nahcolite zone is at 1,693 feet. Below this depth the core contains common to abundant amounts of sodium bicarbonate salt intermixed with oil shale. The core is divided into seven structural zones that reflect changes in joint intensity, core loss and broken core due to natural causes. The zone of poor core recovery is in the Interval between 1,300-1,450 feet. Results of preliminary geophysical log analyses indicate that oil yields determined by Fischer assay compare favorably with yields determined by geophysical log analyses. There is strong evidence that analyses of complete core data from Colorado core holes No. 1 and No. 2 reveal a reliable relationship between geophysical log response and oil yield. The quality of the logs is poor in the rich shale section and the possibility of repeating the logging program should be considered. Observations during drilling, coring, and hydrologic testing of USBM/AEC Colorado core hole No. 2 reveal that the Parachute Creek Member of the Green River Formation is the principal aquifer water in the Parachute Creek Member is under artesian pressure. The upper part of the aquifer has a higher hydrostatic head than, and is hydrologically separated from the lower part of the aquifer. The transmissibility of the aquifer is about 3500 gpd per foot. The maximum water yield of the core hole during testing was about 500 gpm. Chemical analyses of water samples indicate that the content of dissolved solids is low, the principal ions being sodium and bicarbonate. Although the hole was originally cored, to a depth of 2,214 feet, ,the present depth is about 2,100 feet. This report presents a preliminary evaluation of core examination, geophysical log interpretation and hydrological tests from the USBM/AEC Colorado core hole No. 2. The cooperation of the U.S. Bureau of Mines is gratefully acknowledged. The reader is referred to Carroll and others (1967) for comparison of USBM/AEC Col0rado core hole No. 1 with USBM/AEC Colorado core hole No. 2.

Open-File Report↗
USGS2003

Seabird tissue archival and monitoring project: Egg collections and analytical results 1999-2002

In 1998, the U.S. Geological Survey Biological Resources Division (USGS-BRD), the U.S. Fish and Wildlife Service (USFWS) Alaska Maritime National Wildlife Refuge (AMNWR), and the National Institute of Standards and Technology (NIST) began the Seabird Tissue Archival and Monitoring Project (STAMP) to collect and cryogenically bank tissues from seabirds in Alaska for future retrospective analysis of anthropogenic contaminants. The approach of STAMP was similar to that of the Alaska Marine Mammal Tissue Archival Project (AMMTAP). AMMTAP was started in 1987 by NIST and the National Oceanic and Atmospheric Administration (NOAA) as part of the Outer Continental Shelf Environmental Assessment Program sponsored by the Minerals Management Service. Presently sponsored by the USGS-BRD, AMMTAP continues its work as part of a larger national program, the Marine Mammal Health and Stranding Response Program. AMMTAP developed carefully designed sampling and specimen banking protocols. Since 1987, AMMTAP has collected tissues from marine mammals taken in Alaska Native subsistence hunts and has cryogenically banked these tissues at the NIST National Biomonitoring Specimen Bank (NBSB). Through its own analytical work and working in partnership with other researchers both within and outside Alaska, AMMTAP has helped to develop a substantial database on contaminants in Alaska marine mammals. In contrast, data and information is limited on contaminants in Alaska seabirds, which are similar to marine mammals in that they feed near the top of the food chain and have the potential for accumulating anthropogenic contaminants. During its early planning stages, STAMP managers identified the seabird egg as the first tissue of choice for study by the project. There is a relatively long history of using bird eggs for environmental monitoring and for investigating the health status of bird populations. Since 1998, protocols for collecting and processing eggs, and cryogenically banking egg samples have been developed by STAMP (see York et al. 2001). Eggs are being collected on an annual basis for several species at nesting colonies throughout Alaska. Aliquots of these egg samples are being analyzed on a regular basis for persistent organic pollutants and mercury. Results of this work have been published in scientific journals (Christopher et al. 2002) and in conference proceedings (Kucklick et al. 2002; Vander Pol et al. 2002a, 2002b). The intent of this report is to provide an up-to-date description of STAMP. The report contains the most recent egg collection inventory, analytical data, preliminary interpretations based on these data, and a discussion of possible future directions of the project.

Report↗
USGS1980

Description and preliminary map of airborne electromagnetic survey of parts of Iron, Baraga, and Dickinson Counties, Michigan

The data presented herein is from an airborne electromagnetic INPUT* survey conducted by Geoterrex Limited of Canada for the U.S. Geological Survey. The survey area is located in the central part of the Upper Peninsula of Michigan, within parts of Iron, Baraga, and Dickinson Counties. The general area covered is between 46°00' and 46°30' latitude and 88°00' and 88°30' longitude (fig. 1). The INPUT survey was flown as part of a U.S. Geological Survey CUSMAP (Conterminous United States Mineral Appraisal Program) project focusing on the Iron River 2° quadrangle. The survey was flown in order to provide geophysical information which will aid in an integrated geological assessment of mineral potentials of this part of the Iron River 2 quadrangle. The flight-line spacing was chosen to maximize the aerial coverage without a loss of resolution of major lithologic and structural features. East-west flight lines were flown 400 feet above ground at 1/2-mile intervals. Aerial photos were used for navigation and the flight path was recorded on continuous-strip film. A continuously recording total field ground magnetic station was used to monitor variations in the Earth's magnetic field. One north-south line was flown to provide a tie for the magnetic data which was recorded simultaneously with the electromagnetic data by a sensor mounted in the tail of the aircraft. This report is one of two open-file reports. The map in the present report contains locations of the fiducial points, the flight lines, and preliminary locations of anomalies and conductive zones, all plotted on an air photomosaic. The latitude and longitude ticks marked on this map are only approximate due to distortion in air photos used to recover the flight line position. This map is preliminary and is not to be considered a final interpretation. The other report (Reran and Smith, 1980) contains a description of the instrument specifications, a copy of the ground station magnetic data, and a microfilm record of the electromagnetic and magnetic data, with reference to the digital data of the flight records. The purpose of two reports is to make the analog and digital records available separate from the anomaly map. The following sections on the general description of the INPUT system are abridged from a typical interpretation report prepared by Geoterrex Limited of Ottawa, Canada for the U.S. Geological Survey.

Michigan↗
USGS1980

Instrument specifications and geophysical records for airborne electromagnetic survey of parts of Iron, Baraga, and Dickson Counties, Michigan

The data presented herein is from an airborne electromagnetic INPUT* survey conducted by Geoterrex Limited of Canada for the U.S. Geological Survey. The survey area is located in the central part of the Upper Peninsula of Michigan, within parts of Iron, Baraga, and Dickinson Counties. The general area covered is between 46°00' and 46°30' latitude and 88°00' and 88°30' longitude (fig. 1). The INPUT survey was flown as part of a U.S. Geological Survey CUSMAP (Conterminous United States Mineral Appraisal Program) project focusing on the Iron River 2° quadrangle. The survey was flown in order to provide geophysical information which will aid in an integrated geological assessment of mineral potentials of this part of the Iron River 2° quadrangle. The flight line spacing was chosen to maximize the areal coverage without a loss of resolution of major lithologic and structural features. East-west flight lines were flown 400 feet above ground at 1/2 mile intervals. Aerial photos were used for navigation, and the flight path was recorded on continuous-strip film. A continuously recording total field ground magnetic station was used to monitor variations in the Earth's magnetic field. One north-south line was flown to provide a tie for the magnetic data, which was recorded simultaneously with the electromagnetic data by a sensor mounted in the tail of the aircraft. This report is one of two open-file reports. The map in the other report Heran and Smith (1980) shows locations of the fiducial points, the flight lines, preliminary locations of anomalies and conductive zones; all plotted on an air photomosaic. The latitude and longitude ticks marked on this map are only approximate due to distortion in air photos used to recover the flight line position. This map is preliminary and is not to be considered a final interpretation. The present report contains a description of the instrument specifications, a copy of the ground station magnetic data, and a record of the electromagnetic and magnetic data, with reference to the digital data of the flight records. The purpose of two reports is to make the analog and magnetic records available separate from the anomaly map. The following sections on the general description of the INPUT system are abridged from a typical interpretation report prepared by Geoterrex Limited of Ottawa, Canada for the U.S. Geological Survey.

Michigan↗
USGS2002

Southwest Washington coastal erosion workshop report 2000

This report is a compilation of abstracts that correspond to oral presentations and posters presented at the fifth principal investigators workshop of the Southwest Washington Coastal Erosion Study. The workshop was held November 15 - 17, 2000 at the Department of Ecology headquarters building in Olympia, WA. For the fourth consecutive year in November, the workshop convened the entire multi-disciplinary group of scientists and engineers working on the Study or on related projects within the Columbia River littoral cell (CRLC) (Figures 1 and 2). The workshop participants are listed in the List of Attendees section towards the end of this report. The purpose of this workshop was to bring all Study investigators and associated engineers and scientists together to discuss recent work, ongoing tasks, and future research plans in the CRLC. Investigators were asked to present recent data, preliminary interpretations, and research results to invoke discussion and correlation with parallel scientific efforts. The abstracts compiled in this report represent a wealth of information on the CRLC, but because much of the work is in progress, the reader is advised that the information provided herein is preliminary and subject to change.

Oregon;Washington↗
USGS2007

Geophysical mapping of oyster habitats in a shallow estuary: Apalachicola Bay, Florida

This report presents high-resolution geophysical data, interpretive maps, and a preliminary discussion about the oyster habitat and estuary-floor geology within Apalachicola Bay, Florida (fig. 1). During two research cruises, conducted in 2005 and 2006, approximately 230 km² of the bay floor were surveyed using interferometric-bathymetry, sidescan-sonar, and chirp seismic-reflection techniques. The research was conducted as part of a cooperative program between the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration Coastal Services Center (CSC), and the Apalachicola Bay National Estuarine Research Reserve. The Apalachicola Bay National Estuarine Research Reserve was established in 1979 to provide opportunities for long-term monitoring and research to provide a basis for more informed coastal management decisions for this estuary. Apalachicola Bay is the largest oyster fishery in Florida (Whitfield and Beaumariage, 1977), and the primary objective of this program is to develop a suite of maps that define oyster habitat distribution and estuary-floor geology within the bay. The resulting maps will assist in effective management of oyster resources and provide a reference geologic framework for future scientific and applied research.

Florida↗