Mapping the Internal Structure of the Chicxulub Impact Structure

University Of Washington, Seattle WA

Investigators

Abstract

Unsworth 9908851 The Chicxulub impact structure in the Yucatan Peninsula is the site of an extraterrestrial impact 65 million years ago at the end of the Cretaceous period. The structure was initially discovered using gravity and magnetic data, and has subsequently been investigated through geologic studies, drilling and geophysical exploration. It is proposed to explore the Chicxulub structure by using magnetotellurics (MT), a geophysical technique that can image subsurface electrical conductivity. This is a useful quantity to measure at Chicxulub since fractured rock has a low resistivity and re-crystallized melt has a very high resistivity. In collaboration with the Universidad Autonama de Mexico (UNAM) it is proposed to collect MT data that will (1) Locate and map the impact sheet in higher detail than has been previously possible, and (2) define the distribution of fractured basement rock to see if a correlation exists with deep whole crustal penetrating faults imaged on seismic reflection profiles. This study will increase understanding of the formation of multi-ring basins and refine estimates of how large impacts can change the global environment.