International Ocean Discovery Program; Expedition 364 preliminary report; Chicxulub; drilling the K-Pg impact crater; in collaboration with the International Continental Scientific Drilling Program; platform operations, 5 April-31 May 2016; onshore science party, 21 September-15 October 2016

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doi: 10.14379/iodp.pr.364.2017
Author(s): Morgan, Joanna; Gulick, Sean P. S.; Mellett, Claire; Lofi, Johanna; Chenot, Elise; Christeson, Gail; Claeys, Philippe; Cockell, Charles; Coolen, Marco; Ferrière, Ludovic; Gebhardt, Catalina A.; Goto, Kazuhisa; Jones, Heather; Kring, David; Lowery, Christopher; Ocampo-Torres, Rubén; Perez-Cruz, Ligia; Pickersgill, Annemarie E.; Poelchau, Michael; Rae, Auriol; Rasmussen, Cornelia; Rebolledo-Vieyra, Mario; Riller, Ulrich; Sato, Honami; Smit, Jan; Tikoo, Sonia; Tomioka, Naotaka; Whalen, Michael; Wittmann, Axel; Yamagachi, Kosei; Xiao Long; Zylberman, William
International Ocean Discovery Program, Expedition 364 Sientists, College Station, TX
Author Affiliation(s): Primary:
Imperial College London, Department of Earth Science and Engineering, London, United Kingdom
Other:
University of Texas at Austin, United States
British Geological Survey, United Kingdom
Université de Montpellier, France
Université de Bourgogne-Franche Comté, France
Vrije Universiteit Brussel, Belgium
University of Edinburgh, United Kingdom
Curtin University, Australia
Natural History Museum Vienna, Austria
Alfred Wegener Institute, Germany
Tohoku University, Japan
Pennsylvania State University, United States
Lunar and Planetary Institute, United States
Université de Strasbourg, France
Universidad Nacional Autónoma de México, Mexico
University of Glasgow, United Kingdom
University of Freiburg, Germany
University of Utah, United States
Centro de Investigación Científica de Yucatán, Mexico
Universität Hamburg, Germany
Japan Agency for Marine-Earth Science and Technology, Japan
Vrije Universiteit Amsterdam, Netherlands
Rutgers University at New Brunswick, United States
University of Alaska at Fairbanks, United States
Arizona State University, United States
Toho University, Japan
China University of Geosciences-Wuhan, China
Aix Marseille University, France
Source: Preliminary Report - International Ocean Discovery Program, Vol.364, 38p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2372-9562
Note: In English. 95 refs.
Summary: The Chicxulub impact crater, Mexico, is unique. It is the only known terrestrial impact structure that has been directly linked to a mass extinction event and the only terrestrial impact with a global ejecta layer. Of the three largest impact structures on Earth, Chicxulub is the best preserved. Chicxulub is also the only known terrestrial impact structure with an intact, unequivocal topographic peak ring. Chicxulub's role in the Cretaceous/Paleogene (K-Pg) mass extinction and its exceptional state of preservation make it an important natural laboratory for the study of both large impact crater formation on Earth and other planets and the effects of large impacts on the Earth's environment and ecology. Our understanding of the impact process is far from complete, and despite more than 30 years of intense debate, we are still striving to answer the question as to why this impact was so catastrophic. During International Ocean Discovery Program (IODP) Expedition 364, Paleogene sediments and lithologies that make up the Chicxulub peak ring were cored to investigate (1) the nature and formational mechanism of peak rings, (2) how rocks are weakened during large impacts, (3) the nature and extent of post-impact hydrothermal circulation, (4) the deep biosphere and habitability of the peak ring, and (5) the recovery of life in a sterile zone. Other key targets included sampling the transition through a rare midlatitude section that might include Eocene and Paleocene hyperthermals and/or the Paleocene/Eocene Thermal Maximum (PETM); the composition and character of the impact breccias, melt rocks, and peak-ring rocks; the sedimentology and stratigraphy of the Paleocene-Eocene Chicxulub impact basin infill; the chronology of the peak-ring rocks; and any observations from the core that may help us constrain the volume of dust and climatically active gases released into the stratosphere by this impact. Petrophysical property measurements on the core and wireline logs acquired during Expedition 364 will be used to calibrate geophysical models, including seismic reflection and potential field data, and the integration of all the data will calibrate impact crater models for crater formation and environmental effects. The proposed drilling directly contributes to IODP Science Plan goals: Climate and Ocean Change: How resilient is the ocean to chemical perturbations? The Chicxulub impact represents an external forcing event that caused a 75% level mass extinction. The impact basin may also record key hyperthermals within the Paleogene. Biosphere Frontiers: What are the origin, composition, and global significance of subseafloor communities? What are the limits of life in the subseafloor? How sensitive are ecosystems and biodiversity to environmental change? Impact craters can create habitats for subsurface life, and Chicxulub may provide information on potential habitats for life, including extremophiles, on the early Earth and other planetary bodies. Paleontological and geochemical studies at ground zero will document how large impacts affect ecosystems and effects on biodiversity. Earth Connections/Earth in Motion: What are the composition, structure and dynamics of Earth's upper mantle? What mechanisms control the occurrence of destructive earthquakes, landslides, and tsunami? Mantle uplift in response to impacts provides insight into dynamics that differ between Earth and other rocky planets. Impacts generate earthquakes, landslides, and tsunami, and scales that generally exceed plate tectonic processes yield insight into effects, the geologic record, and potential hazards. IODP Expedition 364 was a Mission Specific Platform expedition to obtain subseabed samples and downhole logging measurements from the sedimentary cover sequence and peak ring of the Chicxulub impact crater. A single borehole was drilled into the Chicxulub impact crater on the Yucatan continental shelf, recovering core from 505.7 to 1334.73 m below seafloor with ∼99% core recovery and acquiring downhole logs for the entire depth.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Atlantic Ocean; Biostratigraphy; Breccia; Cenozoic; Chemostratigraphy; Chicxulub Crater; Cores; Cretaceous; Crust; Drilling; Expedition 364; Foraminifera; Geomicrobiology; Gulf of Mexico; Hydrothermal conditions; IODP Site M0077; Impact breccia; Impact craters; Impact features; Impact melts; Impactites; International Ocean Discovery Program; Invertebrata; K-T boundary; Lithostratigraphy; Lower Paleocene; Magnetostratigraphy; Marine drilling; Mass extinctions; Melts; Mesozoic; Metamorphic rocks; Mexico; Microfossils; Nannofossils; North Atlantic; Paleocene; Paleogene; Paleomagnetism; Peak rings; Physical properties; Plantae; Protista; Sedimentary rocks; Stratigraphic boundary; Tertiary; Upper Cretaceous; Well logs; Yucatan Mexico; Yucatan Peninsula
Coordinates: N212700 N212700 W0895700 E0895700
Record ID: 2017020855
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute.