Multibeam mapping of cretaceous-paleogene meteorite impact deposits on the Campeche escarpment, Yucatán, México

Author(s): Gwiazda, R.; Paull, C. K.; Caress, D. W.; Rebolledo-Vieyra, Mario; Fucugauchi, J. U.; Canales, I.; Sumner, E. J.; Tubau Carbonell, Xavier; Lundsten, Eve M.; Anderson, Krystle
Author Affiliation(s): Primary:
Monterey Bay Aquarium Research Institute, Moss Landing, CA, United States
Centro de Investigación Cientifica de Yucatán, Mexico
Universidad Nacional Autónoma de México, Mexico
Universitat de Barcelona, Spain
Volume Title: AGU 2013 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2013; American Geophysical Union 2013 fall meeting, San Francisco, CA, Dec. 9-13, 2013. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The Chicxulub crater in the Yucatan Peninsula, Mexico, at the Cretaceous-Paleogene (K-Pg) boundary, is believed to have been created by the impact of a meteorite ∼65 million years ago. Ejecta from the impact were deposited beyond the crater site and are now buried under >1 km of Cenozoic carbonate sediments. Outcrops of the ejecta are believed to be exposed on the Campeche escarpment, which is the dramatically steep northern edge of the Yucatan Peninsula. A seafloor-mapping cruise aboard the R/V Falkor, equipped with Kongsberg EM302 30 kHz and EM710 70-100 kHz multibeam sonars, was conducted in March 2013 to produce a detailed map of the escarpment. Surveys were conducted along the escarpment face for 612 km, targeting the water depth range between 400 m and the escarpment base at ≤3,700 m. Segments with two distinctive reliefs are observed in the escarpment face: The first type of relief is a continuous slope over the entire surveyed depth, with numerous v-shaped gullies and intervening ridges. In contrast, the second type of relief is characterized by slopes of 5° above ∼2-2.5 km depth with an abrupt change to 25° slopes below. As many as 80 submarine canyons are present along this relief. The canyons are topped with semicircular amphitheaters of gentler slopes above ∼2-2.5 km but rimmed with 500 m high cliffs on the steep slope section below. The steep cliffs appear free from sediment drape and can be traced laterally for large segments of the escarpment, suggesting that these are horizontal units with outcropping strata. The location of the K-Pg boundary on the escarpment can be inferred from its identification on DSDP Leg 17 Site 86, drilled on a terrace at 1,462 m depth, and 200 m from the edge of the escarpment, and on DSDP Leg 17 Site 94, drilled in 1,793 m depth, 5.5 km from the edge of the platform. Based on the biostratigraphy of core cuttings recovered from both boreholes the base of the Tertiary in Site 86 is placed at between 2,016 and 2,081 m, and in Site 94 between 2,427 and 2,436 m depth. Lateral projection of these depths to the face of the escarpment correspond with the abrupt change from the 5° slope to the 25° slope associated with the 500 m high cliff which can be followed laterally for hundreds of kilometers. How much of this 500 m cliff is composed of meteorite impact ejecta or in-place Cretaceous sediments is unknown. Nevertheless, the data from this cruise constrains the location of the ejecta and boundary along most of the horizontal extent of the Campeche escarpment to within a 25 m depth interval, thus providing attractive sampling targets for future expeditions utilizing robotic vehicles.
Year of Publication: 2013
Research Program: DSDP Deep Sea Drilling Project
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Campeche Scarp; Cenozoic; Cores; Cretaceous; DSDP Site 86; DSDP Site 94; Deep Sea Drilling Project; Gulf of Mexico; K-T boundary; Leg 10; Lower Paleocene; Marine sediments; Mesozoic; North Atlantic; Paleocene; Paleogene; Sediments; Stratigraphic boundary; Tertiary; Upper Cretaceous
Coordinates: N243138 N243138 W0882809 W0882809
N225229 N225229 W0905745 W0905745
Record ID: 2015070714
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