ASTR 101 Chapter Notes - Chapter 2: Midwestern United States, Impact Crater, Sisal
5 Sep 2016
School
Course
Professor
Document Summary
Killer crater in the yucatan? (written in 1991) Chicxulub once thrived on the cultivation and export of sisal fibre, but demand dwindled as did town"s fortune. People began to suspect impact crater lies below it, buried by thick layers of limestone sediment. Geologists have been searching for this crater since 1980 when a team proposed an asteroid created the boundary found between cretaceous and tertiary geologic periods. In the boundary is a lot of iridium, which is exists in mere traces in the earth"s crust. Team suggested asteroid of 10 km in size slammed into earth at 40 km/sec. Impact would leave crater of 150 to 200 km across. 130 terrestrial impact sites have been confirmed to date. Hard to find because been ground away by erosion, buried under sediment, or broken up by crustal movement. Also case that it could have landed in ocean. Evidence of quartz suggested it landed on land.
