| Abstract: | The U.S. Geological Survey (USGS) acquired two 1.4-km-long, high-resolution (~5 m vertical resolution) seismic-reflection lines in 2006 that cross near the International Continental Scientific Drilling Program (ICDP)-USGS Eyreville deep drilling site located above the late Eocene Chesapeake Bay impact structure in Virginia, USA. Five-meter spacing of seismic sources and geophones produced high-resolution images of the subsurface adjacent to the 1766-m-depth Eyreville core holes. Analysis of these lines, in the context of the core hole stratigraphy, shows that moderate-amplitude, discontinuous, dipping reflections below ~527 m correlate with a variety of Chesapeake Bay impact structure sediment and rock breccias recovered in the cores. High-amplitude, continuous, subhorizontal reflections above ~527 m depth correlate with the uppermost part of the Chesapeake Bay impact structure crater-fill sediments and postimpact Eocene to Pleistocene sediments. Reflections with ~20-30 m of relief in the uppermost part of the crater-fill and lowermost part of the postimpact section suggest differential compaction of the crater-fill materials during early postimpact time. The top of the crater-fill section also shows ~20 m of relief that appears to represent an original synimpact surface. Truncation surfaces, locally dipping reflections, and depth variations in reflection amplitudes generally correlate with the lithostrati-graphic and sequence-stratigraphic units and contacts in the core. Seismic images show apparent postimpact paleochannels that include the first possible Miocene paleochannels in the Mid-Atlantic Coastal Plain. Broad downwarping in the postim-pact section unrelated to structures in the crater fill indicates postimpact sediment compaction. |
| Genre: | Article |
| ProdID: | 70003484 |
| Citation Author: | Powars, David S.; Catchings, Rufus D.; Goldman, Mark R.; Gohn, Gregory S.; Horton, J. Wright, Jr.; Edwards, Lucy E.; Rymer, Michael J.; Gandhok, Gini |
| Citation Contributing Office: | Eastern Geology and Paleoclimate Science Center |
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| Citation End Page: | 233 |
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| Citation Language: | English |
| Citation Larger Work Title: | Geological Society of America Special Papers |
| Citation LatN: | 0373500 |
| Citation LatS: | 0364500 |
| Citation LonE: | -0754000 |
| Citation LonW: | -0763500 |
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| Citation Phsyical Description: | 25 p. |
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| Citation Publisher: | Geological Society of America |
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| Citation Search Results Text: | High-resolution seismic-reflection images across the ICDP-USGS Eyreville deep drilling site, Chesapeake Bay impact structure; 2009; Article; Journal; Geological Society of America Special Papers; Powars, David S.; Catchings, Rufus D.; Goldman, Mark R.; Gohn, Gregory S.; Horton, J. Wright, Jr.; Edwards, Lucy E.; Rymer, Michael J.; Gandhok, Gini |
| Citation Start Page: | 209 |
| Citation Volume: | 458 |
| Citation Year: | 2009 |
| Type: | citation/reference |
| Text: | High-resolution seismic-reflection images across the ICDP-USGS Eyreville deep drilling site, Chesapeake Bay impact structure; 2009; Article; Journal; Geological Society of America Special Papers; Powars, David S.; Catchings, Rufus D.; Goldman, Mark R.; Gohn, Gregory S.; Horton, J. Wright, Jr.; Edwards, Lucy E.; Rymer, Michael J.; Gandhok, Gini |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (INDEX PAGE): | http://specialpapers.gsapubs.org/content/458/209.abstract |
| Date Other: | Thu, 4 Aug 2011 00:00 -0500 |
| Publisher: | Geological Society of America |
