IODP Expedition 364

IODP Expedition 364, based on IODP Proposal 548-Full3 and Addendum 548-Add4, will address several questions related to large impact crater formation on Earth and other planets, and the effects of large impacts on the Earth's environment and ecology. The expedition target is the unique Chicxulub impact crater, Mexico, which is the only known terrestrial impact structure that has been directly linked to a mass extinction event (the K-Pg mass extinction). Of the three largest impact structures on Earth it is the best-preserved, and is the only terrestrial crater with a global ejecta layer. Additionally, it is the only known terrestrial impact structure with an unequivocal topographic "peak ring."

This expedition aims to drill and core into the Chicxulub impact structure to recover cores from, and above, the peak ring. In doing so, the expedition aims to address several questions, including: 1) what rocks comprise a topographic peak ring and how are peak rings formed; 2) how are rocks weakened during large impacts to allow them to collapse and form relatively wide, flat craters; 3) what caused the environmental changes that led to a mass extinction and what insights arise from biologic recovery in the Paleogene; and 4) what effect does a large impact have on the deep subsurface biosphere and can impacts generate habitats for chemosynthetic life?

The expedition will drill and core a single 1500 m deep borehole at site about 30km northwest of Progreso, Mexico, on the Yucatan shelf, Gulf of Mexico.

Expedition 364 Scientific Prospectus