title: Deep drilling into the Chesapeake Bay impact structure.
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.
authors.affiliation: U.S. Geological Survey, Reston, VA 20192, USA. ggohn@usgs.gov
authors.forename: G S
authors.initials: GS
authors.lastname: Gohn
authors.forename: C
authors.initials: C
authors.lastname: Koeberl
authors.forename: K G
authors.initials: KG
authors.lastname: Miller
authors.forename: W U
authors.initials: WU
authors.lastname: Reimold
authors.forename: J V
authors.initials: JV
authors.lastname: Browning
authors.forename: C S
authors.initials: CS
authors.lastname: Cockell
authors.forename: J W
authors.initials: JW
authors.lastname: Horton
authors.forename: T
authors.initials: T
authors.lastname: Kenkmann
authors.forename: A A
authors.initials: AA
authors.lastname: Kulpecz
authors.forename: D S
authors.initials: DS
authors.lastname: Powars
authors.forename: W E
authors.initials: WE
authors.lastname: Sanford
authors.forename: M A
authors.initials: MA
authors.lastname: Voytek
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology*; D006358:Hot Temperature; D054712:Salinity; D012623:Seawater; D013995:Time; D014768:Virginia