Yucatán subsurface stratigraphy: Implications and constraints for the Chicxulub impact

Abstract

Research Article| October 01, 1995 Yucatán subsurface stratigraphy: Implications and constraints for the Chicxulub impact W. C. Ward; W. C. Ward 1Department of Geology and Geophysics, University of New Orleans, New Orleans, Louisiana 70148 Search for other works by this author on: GSW Google Scholar G. Keller; G. Keller 2Department of Geological and Geophysical Sciences, Princeton University, Princeton, New Jersey 08544 Search for other works by this author on: GSW Google Scholar W. Stinnesbeck; W. Stinnesbeck 3Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León, 67700 Linares, Nuevo León, México Search for other works by this author on: GSW Google Scholar T. Adatte T. Adatte 4Institut de Géologie, Université de Neuchâtel, 2001 Neuchâtel, Switzerland Search for other works by this author on: GSW Google Scholar Author and Article Information W. C. Ward 1Department of Geology and Geophysics, University of New Orleans, New Orleans, Louisiana 70148 G. Keller 2Department of Geological and Geophysical Sciences, Princeton University, Princeton, New Jersey 08544 W. Stinnesbeck 3Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León, 67700 Linares, Nuevo León, México T. Adatte 4Institut de Géologie, Université de Neuchâtel, 2001 Neuchâtel, Switzerland Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1995) 23 (10): 873–876. https://doi.org/10.1130/0091-7613(1995)023<0873:YNSSIA>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation W. C. Ward, G. Keller, W. Stinnesbeck, T. Adatte; Yucatán subsurface stratigraphy: Implications and constraints for the Chicxulub impact. Geology 1995;; 23 (10): 873–876. doi: https://doi.org/10.1130/0091-7613(1995)023<0873:YNSSIA>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Much of the discussion about the effects of an end-of-Cretaceous impact by a large extraterrestrial body in northwestern Yucatán has been done in the context of limited and partly erroneous published data on the Mesozoic stratigraphy of that area. Reexamination of cores and geophysical logs taken in several Pemex wells has produced improved lithologic and biostratigraphic correlation of the Jurassic to Maastrichtian section across the northern Yucatán peninsula. These data suggest that major disturbance of strata by an impact would have been confined to within about 100 km of the proposed impact center near Chicxulub. The only unusual lithologic unit is polymict breccia, which apparently was penetrated at or near the top of the Cretaceous section in all the deep wells of northern Yucatán. This breccia in Pemex wells Yucatán 1, 2, 4, 5A, and 6 is composed predominantly of detrital dolomite, limestone, and anhydrite clasts set in dolomitized carbonate mud matrix, which contains upper Maastrichtian foraminifers. These constituents, mixed with fragments of altered glass or melt rock, shocked quartz and feldspar, and basement rock, suggest an impact as the most likely origin for the breccia. The timing of brecciation is poorly constrained by biostratigraphic data. There is some evidence, however, that the breccia unit is overlain by about 18 m of uppermost Maastrichtian marls, suggesting an impact before the Cretaceous-Tertiary boundary. In addition, there may have been more than one episode of breccia deposition. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.