Impact event Chicxulub Crater. This crater is centered on the Yucatán Peninsula of Mexico and was discovered by Tony Camargo and Glen Pentfield while working as geophysicists for the Mexican oil company PEMEX. What they reported as a circular feature later turned out to be a crater estimated to be in diameter. This convinced the vast majority of scientists that this extinction resulted from a point event that is most probably an extraterrestrial impact and not from increased volcanism and climate change (which would spread its main effect over a much longer time period). Although there is now general agreement that there
Foelsche crater layer of magnetic rock (igneous sill) by the impact event. The age of Foelsche is not well constrained, but it must be younger than the Mesoproterozoic target rocks and older than the Neoproterozoic rocks that partly fill the crater; it has been argued that the age is most likely Neoproterozoic because it appears that the crater was covered by sediments soon after the impact event. Foelsche crater Foelsche is a partly buried impact structure (or astrobleme), the eroded remnant of a former impact crater. It is situated about 85 km southeast of Borroloola in the Northern Territory, Australia, and named