Grain size of Cretaceous-Paleogene boundary sediments from Chicxulub to the open ocean: Implications for interpretation of the mass extinction event

The relationship between the Chicxulub impact event and the Cretaceous-Paleogene (K-Pg) boundary mass extinction has been repeatedly questioned. Specifically, Cretaceous planktonic foraminifera occurring in high-energy sediments in the Gulf of Mexico related to the impact have been used to argue that the impact preceded the mass extinction. Here we address this dispute by comparing grain size data from two Gulf of Mexico sections and a distal, pelagic sequence. Significantly larger grain sizes, combined with evidence for size sorting in the proximal sections, suggest that fossils in boundary deposits are redeposited and cannot be used to assign ages. Thus the grain size data support other evidence that indicates that high-energy deposits from around the Gulf of Mexico correlate stratigraphically with the Chicxulub impact and the K-Pg mass extinction.

[1]  B. Peucker‐Ehrenbrink,et al.  A high-resolution marine 187Os/188Os record for the late Maastrichtian: Distinguishing the chemical fingerprints of Deccan volcanism and the KP impact event , 2009 .

[2]  G. Keller,et al.  New evidence concerning the age and biotic effects of the Chicxulub impact in NE Mexico , 2009, Journal of the Geological Society.

[3]  G. Keller,et al.  Reply to ‘Chicxulub impact predates K–T boundary: New evidence from Brazos, Texas’ Comment by Schulte et al. , 2008 .

[4]  P. Schulte,et al.  Comment on the paper “Chicxulub impact predates K–T boundary: New evidence from Brazos, Texas” by Keller et al. (2007) , 2008 .

[5]  S. Bajpai,et al.  40K–40Ar dating of the Main Deccan large igneous province: Further evidence of KTB age and short duration , 2007 .

[6]  I. N. McCave,et al.  Laser vs. settling velocity differences in silt grainsize measurements: estimation of palaeocurrent vigour , 2006 .

[7]  P. Schulte,et al.  The Cretaceous-Paleogene (K-P) boundary at Brazos, Texas: Sequence stratigraphy, depositional events and the Chicxulub impact , 2006 .

[8]  L. Alegret,et al.  Foraminiferal biostratigraphy and paleoenvironmental reconstruction at the Yaxcopoil‐1 drill hole, Chicxulub crater, Yucatán Peninsula , 2004 .

[9]  J. Smit,et al.  Is the transition impact to post‐impact rock complete? Some remarks based on XRF scanning, electron microprobe, and thin section analyses of the Yaxcopoil‐1 core in the Chicxulub crater , 2004 .

[10]  K. Goto,et al.  Evidence for ocean water invasion into the Chicxulub crater at the Cretaceous/Tertiary boundary , 2004 .

[11]  B. Dressler,et al.  Impactites of the Yaxcopoil‐1 drilling site, Chicxulub impact structure: Petrography, geochemistry, and depositional environment , 2004 .

[12]  G. Keller,et al.  Chicxulub impact predates the K-T boundary mass extinction. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[13]  Mitchell J Malone,et al.  Proceedings of the Ocean Drilling Program, 198 Initial Reports , 2002 .

[14]  F. Anselmetti,et al.  Proceedings of the Ocean Drilling Program. Initial Reports , 2002 .

[15]  J. Pospichal.  Calcareous nannofossils and clastic sediments at the Cretaceous-Tertiary boundary, northeastern Mexico , 1996 .

[16]  T. Hansen,et al.  The first 2 million years after the Cretaceous-Tertiary boundary in east Texas: rate and paleoecology of the molluscan recovery , 1993, Paleobiology.

[17]  P. Sheehan,et al.  Major extinctions of land-dwelling vertebrates at the Cretaceous-Tertiary boundary, eastern Montana , 1992 .

[18]  M. Pilkington,et al.  Chicxulub Crater: A possible Cretaceous/Tertiary boundary impact crater on the Yucatán Peninsula, Mexico , 1991 .

[19]  S. D’Hondt,et al.  Some patterns of planktic foraminiferal assemblage turnover at the Cretaceous-Tertiary boundary , 1991 .

[20]  J. Zachos,et al.  Glass from the Cretaceous/Tertiary boundary in Haiti , 1991, Nature.

[21]  T. Hansen,et al.  A Tsunami Deposit at the Cretaceous-Tertiary Boundary in Texas , 1988, Science.

[22]  C. Officer,et al.  The Cretaceous-Tertiary Transition , 1983, Science.

[23]  L. W. Alvarez,et al.  Extraterrestrial Cause for the Cretaceous-Tertiary Extinction , 1980, Science.

[24]  C. Koeberl.  1.28 – The Geochemistry and Cosmochemistry of Impacts , 2007 .

[25]  H. Thierstein.  Terminal Cretaceous plankton extinctions: A critical assessment , 1982 .