Publications
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Digital engineering aspects of karst map: A GIS version of Davies, W.E., Simpson, J.H., Ohlmacher, G.C., Kirk, W.S., and Newton, E.G., 1984, Engineering aspects of karst: U.S. Geological Survey, National atlas of the United States of America, scale 1:7,
These data are digital facsimiles of the original 1984 Engineering Aspects of Karst map by Davies and others. This data set was converted from a printed map to a digital GIS coverage to provide users with a citable national scale karst data set to use for graphic and demonstration purposes until new, improved data are developed. These data may be used freely with proper citation. Because it has b
Authors
Bret D. Tobin, David J. Weary
Origin of the Blue Ridge escarpment along the passive margin of Eastern North America
The Blue Ridge escarpment is a rugged landform situated within the ancient Appalachian orogen. While similar in some respects to the great escarpments along other passive margins, which have evolved by erosion following rifting, its youthful topographic expression has inspired proposals of Cenozoic tectonic rejuvenation in eastern North America. To better understand the post-orogenic and post-rift
Authors
J.A. Spotila, G.C. Bank, P.W. Reiners, C.W. Naeser, N. D. Naeser, B.S. Henika
Supergroup stratigraphy of the Atlantic and Gulf Coastal Plains (Middle? Jurassic through holocene, Eastern North America)
An inclusive supergroup stratigraphic framework for the Atlantic and Gulf Coastal Plains is proposed herein. This framework consists of five supergroups that 1) are regionally inclusive and regionally applicable, 2) meaningfully reflect the overall stratigraphic and structural history of the Coastal Plains geologic province of the southeastern United States, and 3) create stratigraphic units that
Authors
Robert E. Weems, Jean Self-Trail, Lucy E. Edwards
Geomorphic evolution and geology of Old Currituck Inlet and its flood tidal delta, Virginia/North Carolina, USA (Part I)
No abstract available.
Authors
Marci M. Robinson, R.A. McBride
Old Currituck Inlet, Virginia/North Carolina: Inlet history documented by foraminiferal evidence (Part II)
No abstract available.
Authors
R.A. McBride, Marci M. Robinson
Impact damage to dinocysts from the Late Eocene Chesapeake Bay event
The Chesapeake Bay impact structure, formed by a comet or meteorite that struck the Virginia continental shelf about 35.5 million years ago, is the focus of an extensive coring project by the U.S. Geological Survey and its cooperators. Organic-walled dinocysts recovered from impact-generated deposits in a deep core inside the 85-90 km-wide crater include welded organic clumps and fused, partially
Authors
Lucy E. Edwards, David S. Powars
Ecosystem history of southern and central Biscayne Bay: Summary report on sediment core analyses
During the last century, the environs of Biscayne Bay have been greatly affected by anthropogenic alteration through urbanization of the Miami/Dade County area. The sources, timing, delivery, and quality of freshwater flow into the Bay have been changed by construction of a complex canal system that controls movement of water throughout south Florida. Changes in shoreline and sub-aquatic vegetatio
Authors
G. Lynn Wingard, Thomas M. Cronin, G. S. Dwyer, S. E. Ishman, D. A. Willard, C. W. Holmes, C.E. Bernhardt, C.P. Williams, M. E. Marot, J.B. Murray, R.G. Stamm, J.H. Murray, C. Budet
Evaporite tectonism in the lower Roaring Fork River valley, west-central Colorado
Evaporite tectonism in the lower Roaring Fork River valley in west-central Colorado has caused regional subsidence of a differentially downdropped area in the southern part of the Carbondale collapse center during the late Cenozoic. A prominent topographic depression coincides with this collapse area, and drainage patterns within the collapse area contrast sharply with those outside of it. Miocene
Authors
R. M. Kirkham, Randall K. Streufert, Michael J. Kunk, James R. Budahn, Mark R. Hudson, William J. Perry
The U.S. Geological Survey and the Chesapeake Bay – The role of science in environmental restoration
The Chesapeake Bay is the Nation's largest estuary and historically supported one of the most productive fisheries in the world. In addition to supporting aquatic communities and wildlife, the bay's watershed serves the economic and recreational needs of 15 million people. The fertile soils of the watershed support significant agricultural production. Unfortunately, the commercial, economic, and r
Authors
Roger A. Barlow, John W. Brakebill, John F. Bratton, Vicki S. Blazer, John Karl Bohlke, Owen P. Bricker, Steve M. Colman, Thomas M. Cronin, Cliff R. Hupp, Janet R. Keough, Jurate M. Landwehr, Michael J. Langland, Wayne L. Newell, Matthew Perry, Scott W. Phillips, Steve D. Preston, Nancy B. Rybicki, Nancy S. Simon, Debra A. Willard
By
Ecosystems Mission Area, Water Resources Mission Area, Climate Adaptation Science Centers, Chesapeake Bay Activities, Eastern Ecological Science Center, Florence Bascom Geoscience Center, Maryland-Delaware-D.C. Water Science Center, Pennsylvania Water Science Center, Woods Hole Coastal and Marine Science Center
Correlation of late Cenozoic basaltic lava flows in the Carbondale and Eagle collapse centers in west-central Colorado based on geochemical, isotopic, age, and petrographic data
Major-, minor-, and trace-element abundance data on 220, late Cenozoic, basaltic rocks in and around the Carbondale and Eagle collapse centers in west-central Colorado are combined with isotopic, age, and petrographic data to correlate lava flows and establish the timing and minimum areal extent of collapse events associated with removal of Pennsylvanian evaporite. On the basis of these data, 46 d
Authors
James R. Budahn, D. M. Unruh, Michael J. Kunk, Frank M. Byers, R. M. Kirkham, R. K. Streufert
Tertiary cooling and tectonic history of the White River uplift, Gore Range, and western Front Range, central Colorado: Evidence from fission-track and 39Ar/ 40Ar ages
Apatite fission-track (AFT) data from Proterozoic and Paleozoic rocks in the mountains of north central Colorado (White River Uplift, Gore Range, and western Front Range) record significant cooling that began with uplift and erosion related to the Laramide Orogeny and continued through the Tertiary to Pliocene time. The mountains immediately flanking the Blue River half graben (Williams Fork Mount
Authors
C.W. Naeser, Bruce Bryant, Michael J. Kunk, Karl S. Kellogg, R.A. Donelick, W. J. Perry
40Ar/39Ar ages of late Cenozoic volcanic rocks within and around the Carbondale and Eagle collapse centers, Colorado: Constraints on the timing of evaporite-related collapse and incision of the Colorado River
40Ar/ 39Ar dating results of 133 samples from 84 late Cenozoic volcanic rocks provide emplacement ages that constrain the timing of evaporite collapse and the incision rates of the Colorado River. Our samples are from areas in west-central Colorado, both within and outside of the Carbondale and Eagle collapse centers. Significant pulses of volcanic activity occurred in the intervals from 24 to 22,
Authors
Michael J. Kunk, James R. Budahn, D. M. Unruh, Josette O. Stanley, R. M. Kirkham, Bruce Bryant, R. B. Scott, David J. Lidke, R. K. Streufert