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The U.S. Geological Survey (USGS), at the request of the U.S. Army Environmental Command (USAEC), evaluated the capabilities of two borehole technologies to measure horizontal groundwater velocity and direction of flow in a parallel-plate fractured-rock simulator. A colloidal borescope flowmeter (HB) and a heat-pulse flowmeter (HH) were deployed in 4-inch and 6-inch inner-diameter simulated uncased wells that spanned 0.39- and 1.0-inch apertures with simulated groundwater velocities ranging from 2 to 958 feet per day. Measurements were made at the USGS Hydrologic Instrumentation Facility in the Hydraulics Laboratory and the Indianapolis office of the USGS Ohio-Kentucky-Indiana Water Science Center. Ten measurements...
The heat-pulse flowmeter (HH) used in this testing is a KVA Model 200 system. The instrument computes groundwater vectors from heat arrival and decay in an array of four thermistors that surround a single heat source. An external compass attached to the top of the deployment system is used to orient the flowmeter in the borehole. The HH measured groundwater velocity and flow in the x-y plane. Fuzzy packers were filled with 0.08-inch diameter glass beads for all tests. The HH thermistors were centered over the simulated fracture during measurements. One to four measurements were made with the HH for each simulated flow.
The colloidal borescope flowmeter (HB) used in this testing was developed by AquaVISION, Llc. The instrument employs a charge-coupled device camera, an optical magnification lens (140x), and a light-emitting diode (LED) illumination source to visually track neutrally buoyant colloids (approximately 1-5 microns) moving horizontally through the borehole. The device measured groundwater velocity and flow direction in the x-y (horizontal) plane. The HB magnetometer was checked with a compass to assure proper instrument orientation before deployment into the simulators. Borescope data were collected for each flow condition for a period of at least 30 minutes. After data collection, borescope data were inspected for anomalous...
This release provides the data for a comprehensive survey of geologic structures in the eastern Española Basin of the Rio Grande rift, New Mexico. The release includes data and analyses from 53 individual fault zones and 22 other brittle structures, such as breccia zones, joints, and veins, investigated at a total of just over 100 sites. Structures were examined and compared from poorly lithified Tertiary sediments, as well as Paleozoic sedimentary and Proterozoic crystalline rocks. Data and analyses, include geologic maps; field observations and measurements; orientation, kinematic paleostress analyses and modeling; statistical examination of 575 fault trace lengths derived from aeromagnetic data in the Española...
Categories: Data;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: CGGSC,
Crustal Geophysics and Geochemistry Science Center,
Deformation (geologic),
Faulting (geologic),
Fracture (geologic),
These data are the basis of the figures in the manuscript "A Wideband magnetoresistive sensor for monitoring dynamic fault slip in laboratory fault friction experiments". That report was the result of an investigation of a non-contact, wideband method of sensing dynamic fault slip in laboratory geophysical experiments which employs an inexpensive magnetoresistive sensor, a small neodymium rare earth magnet, and user built application specific wideband signal conditioning electronics. The magnetoresistive sensor generates a voltage proportional to the changing angles of magnetic flux lines, generated by differential motion or rotation of the near-by magnet, through the sensor. The performance of an array of these...
Types: Citation;
Tags: Geophysics,
Menlo Park,
Seismology,
USGS Science Data Catalog (SDC),
fracture (geologic),
The database for the Preliminary Geologic Map of the Cherry Hill Quadrangle, Dinwiddie, Sussex, and Greensville Counties, Virginia geographically straddles the Coastal Plain and Piedmont Provinces along the Tidewater Fall Line. Rocks of the eastern Piedmont Roanoke Rapids terrane crop out in the western part of the quadrangle and consist of greenschist- to amphibolite-facies Neoproterozoic felsic to intermediate metavolcanic rocks, some of which contain flattened quartz phenocrysts and are locally isoclinally folded; greenstone that is locally primary layered; and intrusive metadiorite and metagabbro, much of which has been altered to amphibolite. Most of these rocks are strongly foliated and jointed. Greenschist-facies...
The effects of vertical flowmeter placement relative to the vertical fracture opening were examined using the colloidal borescope flowmeter (HB). For these measurements, the HB measurement interval was located at a depth equal to 0.5-inch above and below the top and bottom edges of the fracture, respectively; at upper and lower edge of the fracture; at the center of the fracture; and 0.25-inch above and below the center of the fracture. The HB measurement interval was radially centered in the borehole. For those tests, the simulated flow direction was 180, aperture was 1.0-inch and the velocity was held steady at 297 ft/d. This sub-study was intended to identify potential influence of turbulent eddies on measured...
The geologic map database of the Great Smoky Mountains National Park region of Tennessee and North Carolina is a result from studies from 1993 to 2003 as part of a cooperative investigation by the U.S. Geological Survey with the National Park Service (NPS). This work resulted in a 1:100,000-scale geologic map derived from mapping that was conducted at scales of 1:24,000 and 1:62,500. The geologic data are intended to support cooperative investigations with the NPS, the development of a new soil map by the Natural Resources Conservation Service, and the All Taxa Biodiversity Inventory. In response to a request by the NPS, we mapped previously unstudied areas, revised the geology where problems existed, and developed...
The Blue Ridge belt in northwestern North Carolina and northeastern Tennessee is composed chiefly of 1,000-million to 1,100-million-year-old metamorphic and plutonic rocks that have been thrust many miles northwestward across unmetamorphosed Cambrian(?) and Cambrian sedimentary rocks of the Unaka belt. The Blue Ridge thrust sheet is rooted on the southeast along the Brevard zone, a zone of strike-slip faulting along which metamorphic and plutonic rocks of the Inner Piedmont belt are juxtaposed with rocks of the Blue Ridge. Near the southeastern edge of the Blue Ridge belt, the Blue Ridge thrust sheet is breached by erosion, and the rocks beneath are exposed in the Grandfather Mountain window, which is 45 miles long...
The 1:100,000-scale geologic map database of the South Boston 30' × 60' quadrangle, Virginia and North Carolina, provides geologic information for the Piedmont along the I-85 and U.S. Route 58 corridors and in the Roanoke River watershed, which includes the John H. Kerr Reservoir and Lake Gaston. The Raleigh terrane (located on the eastern side of the map) contains Neoproterozoic to early Paleozoic(?) polydeformed, amphibolite-facies gneisses and schists. The Carolina slate belt of the Carolina terrane (located in the central part of the map) contains Neoproterozoic metavolcanic and metasedimentary rocks at greenschist facies. Although locally complicated, the slate-belt structure mapped across the South Boston...
These datasets provide the measurements and analytical data used to describe the evolution of Neogene faulting near Blythe, California. The data include structural measurements and results from Ar-Ar and U-Pb geochronology that address the research questions of the associated publication. Structural measurement datasets provide fault surface kinematic measurements and tabulations of structural data used in the manuscript stereoplots. Argon datasets include analytical data from Ar-Ar geochronology. U-Pb datasets include analytical data from calcite samples synkinematic with fault movement. Shear estimate datasets include estimations of fault slip magnitude in the Blythe region. These datasets are associated with...
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