Imperial College London

Dr Gareth Collins

Faculty of EngineeringDepartment of Earth Science & Engineering

Reader in Planetary Science
 
 
 
//

Contact

 

+44 (0)20 7594 1518g.collins Website

 
 
//

Location

 

4.83Royal School of MinesSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Kenkmann:2009:10.1130/2009.2458(25),
author = {Kenkmann, T and Collins, GS and Wittmann, A and W√ľnnemann, K and Reimold, WU and Melosh, HJ},
doi = {10.1130/2009.2458(25)},
journal = {Special Paper of the Geological Society of America},
pages = {571--585},
title = {A model for the formation of the Chesapeake Bay impact crater as revealed by drilling and numerical simulation},
url = {http://dx.doi.org/10.1130/2009.2458(25)},
volume = {458},
year = {2009}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - The combination of petrographic analysis of drill core from the recent International Continental Scientific Drilling Program (ICDP)-U.S Geological Survey (USGS) drilling project and results from numerical simulations provides new constraints for reconstructing the kinematic history and duration of different stages of the Chesapeake Bay impact event. The numerical model, in good qualitative agreement with previous seismic data across the crater, is also roughly consistent with the stratigraphy of the new borehole. From drill core observations and modeling, the following conclusions can be drawn: (1) The lack of a shock metamorphic overprint of cored basement lithologies suggests that the drill core might not have reached the parautochthonous shocked crater floor but merely cored basement blocks that slumped off the rim of the original cavity into the crater during crater modification. (2) The sequence of polymict lithic breccia, suevite, and impact melt rock (1397-1551 m) must have been deposited prior to the arrival of the 950-m-thick resurge and avalanche-delivered beds and blocks within 5-7 min after impact. (3) This short period for transportation and deposition of impactites may suggest that the majority of the impactites of the Eyreville core never left the transient crater and was emplaced by ground surge. This is in accordance with observations of impact breccia fabrics. However, the uppermost part of the suevite section contains a pronounced component of airborne material. (4) Limited amounts of shock-deformed debris and melt fragments also occur throughout the Exmore beds. Shard-enriched intervals in the upper Exmore beds indicate that some material interpreted to be part of the hot ejecta plume was incorporated and dispersed into the upper resurge deposits. This suggests that collapse of the ejecta plume was contemporaneous with the major resurge event(s). Modeling indicates that the resurge flow should have been concluded some 20 min after impact; hence
AU - Kenkmann,T
AU - Collins,GS
AU - Wittmann,A
AU - W√ľnnemann,K
AU - Reimold,WU
AU - Melosh,HJ
DO - 10.1130/2009.2458(25)
EP - 585
PY - 2009///
SN - 0072-1077
SP - 571
TI - A model for the formation of the Chesapeake Bay impact crater as revealed by drilling and numerical simulation
T2 - Special Paper of the Geological Society of America
UR - http://dx.doi.org/10.1130/2009.2458(25)
VL - 458
ER -