Dating of shallow groundwater: Comparison of the transient tracers 3H/3He, chlorofluorocarbons, and 85Kr
Brenda Ekwurzel, Peter Schlosser, William M. Smethie Jr., Niel Plummer, Eurybiades Busenberg, Robert L. Michel, Ralf Weppernig, Martin Stute
1994, Water Resources Research (30) 1693-1708
This paper describes a direct comparison of apparent ages derived from 3H/3He, chlorofluorocarbons (CCl3F and CCl2F2), and 85Kr measurements in shallow groundwater. Wells chosen for this study are completed in the unconfined surficial aquifers in late Cenozoic Atlantic Coastal Plain sediments of the Delmarva Peninsula, on the east coast of the United...
Triggered seismicity and deformation between the Landers, California, and Little Skull Mountain, Nevada, earthquakes
Paul Bodin, Joan Gomberg
1994, Bulletin of the Seismological Society of America (84) 835-843
This article presents evidence for the channeling of strain energy released by the Ms = 7.4 Landers, California, earthquake within the eastern California shear zone (ECSZ). We document an increase in seismicity levels during the 22-hr period starting with the Landers earthquake and culminating 22 hr later with the...
Shear zones formed along long, straight traces of fault zones during the 28 June 1992 Landers, California, earthquake
Arvid M. Johnson, Robert W. Fleming, Kenneth M. Cruikshank
1994, Bulletin of the Seismological Society of America (84) 499-510
Surface rupturing during the 28 June 1992 Landers, California, earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en-echelon fault zones with a total length of 80 km. The offsets were accommodated generally not by faults—distinct slip surfaces—but rather by shear zones,...
Earthquake refraction profiles of the root of the Sierra Nevada
Martha K. Savage, Li Li, Jerry P. Eaton, Craig H. Jones, James N. Brune
1994, Tectonics (13) 803-817
We examine the seismic structure of the Sierra Nevada using records of nine earthquakes and one explosion in and near the Sierra, recorded on stations in the Sierra. We first interpret travel times from these paths, which are confined to a single tectonic block, in terms of...
The volcanic, sedimentologic, and paleolimnologic history of the Crater Lake caldera floor, Oregon:Evidence for small caldera evolution
C. Hans Nelson, Charles R. Bacon, Stephen W. Robinson, David P. Adam, J. Platt Bradbury, John H. Barber Jr., Deborah Schwartz, Ginger Vagenas
1994, Bulletin (106) 684-704
Apparent phreatic explosion craters, caldera-floor volcanic cones, and geothermal features outline a ring fracture zone along which Mount Mazama collapsed to form the Crater Lake caldera during its climactic eruption about 6,850 yr B.P. Within a few years, subaerial deposits infilled the phreatic craters and then formed a thick...
A seismotectonic model for the 300-kilometer-long eastern Tennessee seismic zone
C.A. Powell, G. A. Bollinger, M.C. Chapman, M.S. Sibol, A. C. Johnston, R. L. Wheeler
1994, Science (264) 686-688
Ten years of monitoring microearthquakes with a regional seismic network has revealed the presence of a well-defined, linear zone of seismic activity in eastern Tennessee. This zone produced the second highest release of seismic strain energy in the United States east of the Rocky Mountains during the last decade, when...
Conflicting tectonics? Contraction and extension at middle and upper crustal levels along the Cordilleran Late Jurassic arc, southeastern California
Mark J. Davis, Daniel L. Farber, Joe L. Wooden, J. Lawford Anderson
1994, Geology (22) 247-250
Effects of mid-Mesozoic contraction followed closely in time by extension are present in mid- to upper-crustal plutonic rocks in the Chuckwalla Mountains of the eastern Transverse Ranges, California. Late Jurassic movement along a steeply dipping, right-lateral mylonitic shear zone is bracketed between 159 and 147 Ma via U-Pb dated plutons....
Persistence of metals in soil and selected vertebrates in the vicinity of the Palmerton zinc smelters
G.L. Storm, G.J. Fosmire, E.D. Bellis
1994, Journal of Environmental Quality (23) 508-514
Concentration of Cd, Pb, Zn, and Cu in soil and wildlife at the Palmerton zinc smelter site in eastern Pennsylvania were determined 6 yr after zinc smelting was terminated in 1980. Levels of the four metals were higher in litter (01 and 02 horizon) than in soil (A1 horizon), and...
High-precision 40Ar/39Ar age spectrum dating of sanidine from the Middle Pennsylvanian Fire Clay tonstein of the Appalachian basin
Michael J. Kunk, Charles L. Rice
1994, GSA Special Papers (294) 105-112
40Ar/39Ar plateau age spectra of seven sanidine samples from the Fire Clay tonstein (Middle Pennsylvanian), collected along a 300-km traverse in the Appalachian basin, range from 310.3 to 311.4 Ma. All plateau ages agree, within the limits of analytical precision, with their respective total gas ages. This agreement, together with...
40Ar/39Ar chronology and volcanology of silicic volcanism in the Davis Mountains, Trans-Pecos Texas
Christopher D. Henry, Michael J. Kunk, W. C. McIntosh
1994, GSA Bulletin (106) 1359-1376
Field studies and 40Ar/39Ar dating reveal that silicic volcanism in the Davis Mountains part of the Trans-Pecos Texas volcanic field occurred in six episodes at 0.3 m.y. intervals between 36.8 and 35.3 Ma. Additionally, two groups of silicic intrusions were emplaced at 34.6 and 32.8 Ma. This episodicity is similar to...
40Ar 39Ar age constraints on neogene sedimentary beds, Upper Ramparts, half-way Pillar and Canyon village sites, Porcupine river, east-central Alaska
Michael J. Kunk, H. Rieck, T. D. Fouch, L. David Carter
1994, Quaternary International (22-23) 31-42
40Ar/39Ar ages of volcanic rocks are used to provide numerical constraints on the age of middle and upper Miocene sedimentary strata collected along the Porcupine River. Intercalated sedimentary rocks north of latitude 67°10′N in the Porcupine terrane of east-central Alaska contain a rich record of plant fossils. The fossils are valuable...
The Pennsylvanian Fire Clay tonstein of the Appalachian basin—Its distribution, biostratigraphy, and mineralogy
C. L. Rice, Harvey E. Belkin, T.W. Henry, R. E. Zartman, Michael J. Kunk
1994, GSA Special Papers (294) 87-104
The Middle Pennsylvanian Fire Clay tonstein, mostly kaolinite and minor accessory minerals, is an altered and lithified volcanic ash preserved as a thin, isochronous layer associated with the Fire Clay coal bed. Seven samples of the tonstein, taken along a 300-km traverse of the central Appalachian basin, contain cogenetic phenocrysts...
Predators of the Whitetail
Daniel B. Fagre
1994, Book chapter, Deer
white-tailed deer have long been important prey for large predators. Before Europeans colonized North America, deer roaming the forested region east of the Great Plains and areas along the Gulf of Mexico were hunted by wolves and mountain lions, and by Native Americans for food and clothing materials. Today, wolves...
Evaluating decision processes study: Eastman Falls project: Pemigewasset River, New Hampshire
J. G. Taylor
1994, Report
No abstract available....
Correlation and age of the Upper Jurassic Morrison Formation from magnetostratigraphic analysis
Maureen B. Steiner, S. G. Lucas, Eugene Merle Shoemaker
Mario V. Caputo, James A. Peterson, Karen J. Franczyk, editor(s)
1994, Book chapter, Mesozoic systems of the Rocky Mountain region, USA, 1994
The magnetostratigraphy of the Morrison Formation of east-central New Mexico resembles that of three western Colorado sections. Magnetic polarity and lithology agree among the sections, indicating the correlation potential of magnetostratigraphy in this lithologically complex formation. Both magnetostratigraphy, lithology, and paleopoles divide the formation into two parts. The lower...
Mines, prospects, and occurrences of nonmetallic mineral commodities in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina
John P. D’Agostino, Bruce J. O’Connor, Alan J.W. Zupan, Arthur H. Maybin III
1994, Miscellaneous Field Studies Map 2215-D
Mines, prospects, and occurrences of nonmetal mineral commodities in the Greenville 1° x 2° quadrangle are tabulated in this report. There are 488 symbols representing 579 mines, prospects, and occurrences located in the quadrangle. There are 379 symbols used for 466 features in Georgia, 106 symbols for 110 features in...
Map showing seismicity and sandblows in the vicinity of New Madrid, Missouri
B. Susan Rhea, Arthur C. Tarr, Russell L. Wheeler
1994, Miscellaneous Field Studies Map 2264-A
This is one of a series of five seismotectic maps of the seismically active New Madrid, Missouri, area (table 1; Wheeler and others, 1992). The map area centers near the sites of three great earthquakes that struck during the winter of 1811-12 (Fuller, 1912; Nuttli, 1973). These earthquakes and continuing...
Mines, prospects, and occurrences of metallic (excluding gold), pegmatite, and rare-earth mineral commodities in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina
John P. D’Agostino, Alan Jon Zupan, Arthur H. Maybin III, Charlotte E. Abrams, Jerry M. German
1994, Miscellaneous Field Studies Map 2215-B
All of the known mines, prospects, and occurrences of metallic (excluding gold, pegmatite, and rare-earth mineral commodities for the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order for each county (fig. 1), the map number of each item, which correlates and locates...
Gold occurrences in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina
John P. D’Agostino, George T. Mason, Alan J.W. Zupan, Arthur H. Maybin III, Jerry M. German, Charlotte E. Abrams
1994, Miscellaneous Field Studies Map 2215-C
All of the gold mines, prospects, placers, and occurrences known in the Greenville 1° x 2° quadrangle are tabulated in this report. The table lists, in consecutive order by county (fig. 1), the map number of each feature, which is located either on the accompanying Greenville 1° x 2° quadrangle...
Guidebook on the geology, history, and surface-water contamination and remediation in the area from Denver to Idaho Springs, Colorado
Ronald C. Severson
K. C. Stewart, editor(s)
1994, Circular 1097
This guidebook for a 1-day drive in the Front Range west of Denver, Colorado, includes commentary on mountain landscapes, notes on the colorful mining history of the area, and discussions on the geology and some miningrelated environmental hazards in the Idaho Springs area. It was originally prepared as U.S. Geological...
Major 10.2-Ma rhyolitic volcanism in the eastern Snake River plain, Idaho: Isotopic age and stratigraphic setting of the Arbon Valley Tuff Member of the Starlight Formation
Karl S. Kellogg, S. S. Harlan, H. H. Mehnert, L.W. Snee, K. L. Pierce, W. R. Hackett, D. W. Rodgers
1994, Bulletin 2091
No abstract available....
Geophysical database of the east coast of the United States northern Atlantic margin: Velocity analyses
Kim D. Klitgord, C. M. Schneider
1994, Open-File Report 94-192
Geophysical database of the East Coast of the United States northern Atlantic margin: Cross sections and gridded database (Georges Bank Basin, Long Island Platform, and Baltimore Canyon Trough)
Kim D. Klitgord, C. W. Poag, C. M. Schneider, L. North
1994, Open-File Report 94-637
No abstract available....
Atmospheric circulation and snowpack in the Gunnison River Basin
Gregory J. McCabe
1994, Conference Paper, Proceedings of the 21st Annual Conference on Water Policy and
Winter mean 700-millibar height anomalies over the eastern North Pacific Ocean and the western United States are related to variability in snowpack accumulations measured on or about April 1 in the Gunnison River Basin in Colorado. Higher-than-average snowpack accumulations are associated with negative 700-millibar height anomalies (anomalous cyclonic circulation) over...
Ground-water levels and directions of flow near the Industrial Excess Landfill, Uniontown, Ohio, March 1994
Denise H. Dumouchelle, E. Scott Bair
1994, Water-Resources Investigations Report 94-4136
Industrial Excess Landfill (IEL), a U.S. Environmental Protection Agency Superfund site, is a closed landfill in northeastern Ohio. In March 1994, personnel from the U.S. Geological Survey, Ohio Environmental Protection Agency, and PRC Environmental Management, Inc., measured water levels in 149 wells in the area. Surface-water altitudes were measured at...
