Mass extinctions.  occur at the Cretaceous-Tertiary boundary (K-T), the Triassic-Jurassic boundary (TR-J), and the Permian-Triassic boundary (P-TR).  The K-T extinction wiped out the dinosaurs, among numerous other biological groups and was likely caused by the impact of a large asteroid to form the Chicxulub crater, Yucatan peninsula, Mexico.  A massive outpouring of  lava formed the Deccan traps (basaltic rocks) at this time. The TR-J extinction is associated with CAMP, the Central Atlantic Magmatic Province, which includes the basalt flows in the Newark, Fundy, and Argana basin.  The P-TR extinction is associated with the Siberian traps.  Modified from Sepkoski (1997) and Olsen (1999).