Deep Drilling into the Chesapeake Bay Impact Structure.

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Bibliographic Details
Title:	Deep Drilling into the Chesapeake Bay Impact Structure.
Authors:	Gohn, G. S., Koeberl, C., Miller, K. G., Reimold, W. U., Browning, J. V., Cockell, C. S., Horton Jr., J. W., Kenkmann, T., Kulpecz, A. A., Powars, D. S., Sanford, W. E., Voytek, M. A.
Source:	Science (pre-March 2025). 6/27/2008, Vol. 320 Issue 5884, p1740-1745. 6p. 1 Diagram, 2 Graphs, 1 Map.
Subjects:	Industrial contamination, Sedimentary structures, Sedimentology, Geology, Groundwater, Hydrology
Geographic Terms:	Chesapeake Bay (Md. & Va.), Maryland, Virginia
Abstract:	Samples from a 1.76-kilometer-deep corehole drilled near the center of the late Eocene Chesapeake Bay impact structure (Virginia, USA) reveal its geologic, hydrologic, and biologic history. We conducted stratigraphic and petrologic analyses of the cores to elucidate the timing and results of impact-melt creation and distribution, transient-cavity collapse, and ocean-water resurge. Comparison of post-impact sedimentary sequences inside and outside the structure indicates that compaction of the crater fill influenced long-term sedimentation patterns in the mid-Atlantic region. Salty connate water of the target remains in the crater fill today, where it poses a potential threat to the regional groundwater resource. Observed depth variations in microbial abundance indicate a complex history of impact-related thermal sterilization and habitat modification, and subsequent post-impact repopulation. [ABSTRACT FROM AUTHOR]
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Database:	Psychology and Behavioral Sciences Collection

Description
Abstract:	Samples from a 1.76-kilometer-deep corehole drilled near the center of the late Eocene Chesapeake Bay impact structure (Virginia, USA) reveal its geologic, hydrologic, and biologic history. We conducted stratigraphic and petrologic analyses of the cores to elucidate the timing and results of impact-melt creation and distribution, transient-cavity collapse, and ocean-water resurge. Comparison of post-impact sedimentary sequences inside and outside the structure indicates that compaction of the crater fill influenced long-term sedimentation patterns in the mid-Atlantic region. Salty connate water of the target remains in the crater fill today, where it poses a potential threat to the regional groundwater resource. Observed depth variations in microbial abundance indicate a complex history of impact-related thermal sterilization and habitat modification, and subsequent post-impact repopulation. [ABSTRACT FROM AUTHOR]
ISSN:	00368075
DOI:	10.1126/science.1158708