Paper No. 245-6
Presentation Time: 9:15 AM
HABITAT OF THE NASCENT CHICXULUB CRATER
BRALOWER, Timothy1, COSMIDIS, Julie2, FANTLE, Matthew S.3, FREEMAN, Katherine H.4, GULICK, Sean P.S.5, HAJEK, Elizabeth6, HEANEY, Peter J.7, JONES, Heather1, KUMP, Lee R.8, LOWERY, Christopher9, LYONS, Shelby10, MORGAN, Joanna V.11, PASSEY, Benjamin H.12, VAJDA, Vivi13, WHALEN, Michael T.14, WITTMANN, Axel15, ARTEMIEVA, Natalia16, COCKELL, Charles17, FARLEY, Kenneth A.18, GARBER, Joshua M.19, GONZALEZ, Matthew6, GRICE, Kliti20, KRING, David A.21, SCHAEFER, Bettina20, TIKOO, Sonia M.22 and ZACHOS, James C.23, (1)Department of Geosciences, Penn State University, University Park, PA 1682, (2)Department of Geosciences, Penn State University, 408 Deike Building, University Park, PA 16802, (3)Department of Geosciences, The Pennsylvania State University, University Park, PA 16802, (4)Department of Geoscience, Pennsylvania State University, University Park, PA 16801, (5)University of Texas, Jackson School of Geosciences, Institute for Geophysics and Department of Geological Sciences, J.J. Pickle Research Campus, Bldg. 196, 10100 Burnet Rd., Austin, TX 78758, (6)Department of Geosciences, Penn State University, 511 Deike Building, University Park, PA 16802, (7)Dept. of Geosciences, Pennsylvania State University, 540 Deike Bldg, University Park, PA 16802, (8)Department of Geosciences, Pennsylvania State University, 116 Deike Building, University Park, PA 16802, (9)Jackson School of Geosciences, Institute for Geophysics, University of Texas at Austin, 10601 Exploration Way, Austin, TX 78758, (10)Department of Geosciences, Pennsylvania State University, State College, PA 16802, (11)Department of Earth Science and Engineering, Imperial College London, Prince Consort Road, South Kensington, London, SW7 2BP, United Kingdom, (12)Department of Earth & Environmental Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, MI 48109, (13)Swedish Museum of Natural History, Dept of Palaeobotany, Box 50001, Stockholm, S-104 05, Sweden, (14)Department of Geology and Geophysics, University of Alaska Fairbanks, P.O. Box 755780, Fairbanks, AK 99775, (15)LeRoy Eyring Center For Solid State Science, Arizona State University, Tempe, AZ 85287, (16)Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719, (17)School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom, (18)Division of Geological and Planetary Sciences, California Institute of Technology, Mail Stop 100-23, Pasadena, CA 91125, (19)Department of Geological Sciences, University of Texas at Austin, 1 University Station C1100, Austin, TX 78712; Department of Geosciences, Pennsylvania State University, State College, PA 16802, (20)Department of Chemistry, Curtin University of Technology, Kent St, Bentley, 6845, Australia, (21)NASA Solar System Exploration Research Virtual Institute, Center for Lunar Science and Exploration, Lunar and Planetary Institute, 3600 Bay Area BLVD, Houston, TX 77058, (22)Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway Township, NJ 08854, (23)Earth & Planetary Sciences Department, Univ California - Santa Cruz, Santa Cruz, CA 95064
Drilling on the peak ring of the Chicxulub Crater at Site M0077 during International Ocean Discovery Program-Continental Scientific Drilling Program Expedition 364 recovered possibly the most complete record of the immediate aftermath of the impact at the Cretaceous-Paleogene boundary. This record is contained within deposits formed by initial resurge into the crater followed by those laid down by tsunami and seiche waves. Charcoal layers at the top of the tsunami and seiche deposits derived from impact-induced wildfires suggest deposition within hours to decades after the impact. Seiche deposits are composed of calcite formed by decarbonation of the target limestone during impact followed by carbonation at the sea floor. Deep-sea temperatures in the crater recorded by clumped isotopes of these carbonates ranged between 50 and 90
oC indicative of impact-induced hydrothermal activity. Strontium isotope values and alteration of charcoal to pyrite and petrified wood supports this interpretation. Veins with chlorite and sphalerite suggest conduits with higher temperature fluids in the carbonate section.
The crater became a habitat for life soon after impact with an earliest Danian nannoplankton and dinocyst assemblage appearing at the top of the tsunami bed. Diversity dropped at the top of the seiche deposits where a monogeneric calcareous dinoflagellate resting cyst assemblage is found without other nannoplankton or dinocysts, suggesting deteriorating environmental conditions. Microbial fossils made of apatite and calcite at the top of the seiche deposits suggest a thriving bacterial community in the surface ocean and at the seafloor, which we postulate was supported by energy and nutrients supplied by hydrothermal activity.
![[Visit Client Website]](/img/gsa/cfp_banner_2019am.png)