Ref.: Jackson, John C., J. Wright Horton, Jr., I-MIng Chou, and Harvey E. Belkin (2006), A shock-induced polymorph of anatase and rutile from the Chesapeake Bay impact structure, Virginia, USA: American Mineralogist: 91: 604-608; Powars, D.S. and T.S. Bruce (1999), The effects of the Chesapeake Bay impact crater on the geological framework and correlation of hydrogeologic units of the lower York-James peninsula, Virginia, USGS PP 1612, 82 p. [http://pubs.usgs.gov/prof/p1612]; Poag, C.W., C. Koberl, and W.U. Reimold (2004), The Chesapeake Bay impact crater - Geology and geophysica of a late Eocene submarine impact structure, 522 p. (plus CD-ROM), Springer-Verlag, New York; Horton, J.W., Jr., J.N. Aleinikoff, M.J. Kunk, G.S. Gohn, L.E. Edwards J.M. Self-Trail, D.S. Powars, G.A. Izett (2005c), Recent research on the Chesapeake Bay impact structure, USA-Impact debris and reworked ejecta. In T. Kenkmann, F. Hörz, and A. Deutsch, Editors, Large meteorite impacts III. Geological Society of America Special Paper 384: 147-170; Horton, J.W., Jr., G.S. Gohn, D.S. Powars, J.C. Jackson, J.M. Self-Trail, L.E. Edwards, and W.E. Sanford (2004), Impact breccias of the central uplift, Chesapeake Bay impact structure: initial results of a test hole at Cape Charles, Virginia. Geological Society of America Abstracts with Program: 36: 266; Horton, J.W., Jr., G.S. Gohn, J.C. Jackson, J.N. Aleinikoff, W.E. Sanford, L.E. Edwards, and D.S. Powars (2005b), Results from a scientific test hole in the central uplift, Chesapeake Bay impact structure, Virginia, USA. Proceedings of the Lunar and Planetary Science Conference XXXVI, Abstract 2003; Sanford, W.E., G.S. Gohn, D.S. Powars, J.W. Horton, Jr., L.E. Edwards, J.M. Self-Trail, and R.H. Morin (2004), Drilling the central crater of the Chesapeake Bay impact structure: a first look. EOS, Transactions American Geophysical Union: 85, 369, 377.
A buried, late Eocene impact structure formed about 35 million years ago. It is 85 km wide and consists of a central crater, having a broad central uplift surrounded by an elliptical moat, and a surrounding annular trough of slumped, fluidized sediments.
There are three main lithostratigraphic intervals delineated in a test hole based on cuttings and cores plus geophysical logs: 1) A lower crater section of crystalline-clast breccia (including suevite) and brecciated gneiss, 2) an upper crater section of sediment-clast breccia, and 3) post-impact sediments.
Drill cores from 744 to 823 meters of depth found to contain the listed species.
