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TitleSeismic images of Chicxulub impact melt sheet and comparison with the Sudbury structure
AuthorBarton, P J; Grieve, R A F; Morgan, J V; Surendra, A T; Vermeesch, P M; Christeson, G L; Gulick, S P S; Warner, M R
SourceLarge meteorite impacts and planetary evolution IV; by Reimold, W U (ed.); Gibson, R L (ed.); Geological Society of America, Special Paper no. 465, 2010 p. 103-113,
Alt SeriesEarth Sciences Sector, Contribution Series 20080730
PublisherGeological Society of America
Mediapaper; on-line; digital
File formatpdf
AreaChicxulub; Mexico
Lat/Long WENS -89.5333 -89.5000 21.4167 21.3833
Subjectsextraterrestrial geology; craters; meteorite craters; morphology; seismic reflection surveys; seismic surveys; seismic interpretations; seismic refraction surveys; Chicxulub impact crater
Illustrationslocation maps; seismic profiles; plots
Released2010 11 24
AbstractChicxulub is the only known impact structure with a fully preserved peak ring on Earth and forms an important natural laboratory for the study of large craters and understanding of large-scale cratering on Earth and other planets. Seismic data collected in 1996 and 2005 reveal detailed images of the uppermost crater in the central basin at Chicxulub. Seismic reflection profiles show a reflective layer about 1 km beneath the apparent crater floor, topped by upwardly concave reflectors interpreted as saucer-shaped sills. The upper part of this reflective layer is coincident with a thin high-velocity layer identified by analysing refractions on the 6 km seismic streamer data. The high-velocity layer is almost horizontal and appears to be contained within the peak ring structure. We argue that this reflective layer is the predicted coherent melt sheet formed during impact, and may be comparable with the unit known as the Sudbury Igneous Complex at the Sudbury impact structure. The Sudbury Igneous Complex, interpreted as a differentiated impact melt sheet, appears to have a similar scale and geometry, and an uppermost lithological sequence with a velocity high at the top and a velocity inversion beneath. This comparison suggests that Chicxulub crater also contains a coherent differentiated melt sheet.

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