Post-Chicxulub depositional and diagenetic history of the northwestern Yucatan Peninsula,Mexico |
| |
| Affiliation: | 1. Northern Illinois University, Department of Geology and Environmental Geosciences, DeKalb, IL 60115, USA;2. University of New Orleans, Department of Geology and Geophysics, New Orleans, LA 70148, USA;3. Indiana University Bloomington, Department of Geological Sciences, Bloomington, IN 47405, USA;1. Department of Electrical and Computer Engineering, Southern Illinois University, Carbondale, IL 62901, USA;2. Department of Medical Microbiology, Immunology, and Cell Biology, School of Medicine, Southern Illinois University, Springfield, IL 62794, USA;1. Department of Mechanical Engineering and Energy Processes, Southern Illinois University Carbondale, Carbondale, IL 62901, USA;2. Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA;3. Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA;4. Howard Hughes Medical Institute, Johns Hopkins University, Baltimore, MD 21205, USA;5. Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA;6. Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA;1. Department of Physics, Southern Illinois University, Carbondale, IL 62901, United States;2. JILA and Department of Physics, University of Colorado Boulder and NIST, Boulder, CO 80309, USA;3. Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden;4. Materials Theory, ETH Zürich, Wolfgang-Pauli Strasse 27, Zürich, Switzerland;5. Helmholtz Zentrum Berlin für Materialien und Energie GmbH, BESSY II, Berlin, Germany;6. Center for Materials for Information Technology, University of Alabama, Tuscaloosa, AL 35487, United States |
| |
| Abstract: | The Chicxulub Sedimentary Basin of the northwestern Yucatan Peninsula, Mexico, which was formed because of the largest identified Phanerozoic bolide impact on Earth, became a site of deposition of dominantly marine carbonate sediments during most of the Cenozoic Era. This is a study of the filling and diagenetic history of this basin and surrounding areas. The study makes use of lithologic, biostratigraphic, petrographic, and geochemical data obtained on core samples from boreholes drilled throughout the northwestern Yucatan Peninsula.The core sample data indicate that: 1) The Chicxulub Sedimentary Basin concentrated the deposition of pelagic and outer-platform sediments during the Paleocene and Eocene, and, in places, during the Early Oligocene, as well, and filled during the Middle Miocene, 2) deeper-water limestone also is present within the Paleocene and Lower Eocene of the proposed Santa Elena Depression, which is located immediately south of the Basin, 3) shallow-water deposits are relatively more abundant outside the Basin and Depression than inside, 4) the autigenic and allogenic silicates from the Paleogene formations are the most abundant inside the Depression, 5) sediment deposition and diagenesis within the Basin also were controlled by impact crater topography, 6) the abundance of the possible features of subaerial exposure increases upward and outward from the center of the Basin, and 7) the formation of replacive low-magnesium calcite and dolomite, dedolomitization, dissolution, and precipitation of vug-filling calcite and dolomite cement have been more common outside the Basin than inside.δ18O in whole-rock (excluding vug-filling) calcite from core samples ranges from − 7.14‰ to + 0.85‰ PDB. δ13C varies from − 6.92‰ to + 3.30‰ PDB. Both stable isotopes correlate inversely with the abundance of subaerial exposure features indicating that freshwater diagenesis has been extensive especially outside and at the edge of the Chicxulub Sedimentary Basin.δ18O and δ13C in whole-rock (excluding vug-filling) dolomite ranges from − 5.54‰ to + 0.87‰ PDB and − 4.63‰ to + 3.38‰ PDB, respectively. Most dolomite samples have negative δ18O and positive δ13C suggesting that replacive dolomitization involved the presence of a fluid dominated by freshwater and/or an anomalously high geothermal gradient.Most dolomite XRD-determined mole percent CaCO3 varies between 51 and 56. Replacive dolomite is larger, more euhedral, and less stoichiometric inside the Chicxulub Sedimentary Basin than outside. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
