Publications
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Evaporite tectonism in the lower Roaring Fork River valley, west-central Colorado 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...
Authors
R. M. Kirkham, Randall Streufert, Michael Kunk, James Budahn, Mark R. Hudson, William Perry
The U.S. Geological Survey and the Chesapeake Bay – The role of science in environmental restoration 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...
Authors
Roger Barlow, John Brakebill, John Bratton, Vicki S. Blazer, John Karl Bohlke, Owen Bricker, Steve Colman, Thomas Cronin, Cliff Hupp, Janet Keough, Jurate Landwehr, Michael Langland, Wayne Newell, Matthew Perry, Scott Phillips, Steve Preston, Nancy Rybicki, Nancy Simon, Debra 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 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...
Authors
James Budahn, D. Unruh, Michael Kunk, Frank Byers, R. M. Kirkham, R. 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 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...
Authors
C. Naeser, Bruce Bryant, Michael Kunk, Karl Kellogg, R.A. Donelick, W. 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 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...
Authors
Michael Kunk, James Budahn, D. Unruh, Josette Stanley, R. M. Kirkham, Bruce Bryant, R. Scott, David Lidke, R. Streufert
Eagle collapse center: Interpretation of evidence for late Cenozoic evaporite-related deformation in the Eagle River basin, Colorado Eagle collapse center: Interpretation of evidence for late Cenozoic evaporite-related deformation in the Eagle River basin, Colorado
Evaporite tectonism resulted in deformation and collapse over an area of ~2500 km2 that is referred to as the Eagle collapse center. The collapse center includes much of the Eagle and Colorado River drainage basins between Vail, Dotsero, and McCoy, Colorado. The volume loss of evaporitic rocks by dissolution in the collapse center is estimated to be nearly 1700 km33 . Before ca. 10 Ma...
Authors
David Lidke, Mark R. Hudson, R. Scott, Ralph Shroba, Michael Kunk, W. Perry, R. M. Kirkham, James Budahn, R. Streufert, J.O. Stanley, B.L. Widmann
Structural and tectonic setting of the Charleston, South Carolina, region: Evidence from the Tertiary stratigraphic record Structural and tectonic setting of the Charleston, South Carolina, region: Evidence from the Tertiary stratigraphic record
Eleven upper Eocene through Pliocene stratigraphic units occur in the subsurface of the region surrounding Charleston, South Carolina. These units contain a wealth of information concerning the long-term tectonic and structural setting of that area. These stratigraphic units have a mosaic pattern of distribution, rather than a simple layered pattern, because deposition, erosion, and...
Authors
R.E. Weems, W.C. Lewis
Stream piracy in the Black Hills: A geomorphology lab exercise Stream piracy in the Black Hills: A geomorphology lab exercise
The Black Hills of South Dakota exhibits many fine examples of stream piracy that are very suitable for teaching geomorphology lab exercises. This lab goes beyond standard topographic map interpretation by using geologic maps, well logs, gravel provenance and other types of data to teach students about stream piracy. Using a step-by-step method in which the lab exercises ramp up in...
Authors
Brent Zaprowski, Edward Evenson, Jack Epstein
Road log and stop descriptions; Day 1, Stop 1; Delaware Water Gap; geologic overview, stratigraphy, structure, formation of the gap, and glacial geology Road log and stop descriptions; Day 1, Stop 1; Delaware Water Gap; geologic overview, stratigraphy, structure, formation of the gap, and glacial geology
No abstract available.
Authors
Jack Epstein
Structural relations along the Taconic unconformity between New York, New Jersey, and Pennsylvania Structural relations along the Taconic unconformity between New York, New Jersey, and Pennsylvania
No abstract available.
Authors
Jack Epstein, Peter Lyttle
Structural geology of the Delaware Water Gap National Recreation Area Structural geology of the Delaware Water Gap National Recreation Area
No abstract available.
Authors
Jack Epstein
Stratigraphy in the region of Delaware Water Gap National Recreation Area Stratigraphy in the region of Delaware Water Gap National Recreation Area
No abstract available.
Authors
Jack Epstein