Remote Faulting Triggered by Strong Seismic Waves from the Cretaceous-Paleogene Asteroid Impact

摘要

A normal-fault offsets the Cretaceous-Paleogene boundary layer and lower units at the well-known Madrid and Long's Canyon outcrops near Trinidad, Colorado, but not the overlying units. Seismite structures are present at both sites. Strong seismic waves from the Chicxulub crater likely triggered an event on the exposed fault that has not slipped again in its history. There are similarly numerous fault splays each with small offsets at the Goat Hill site near Raton, New Mexico. The faults offset the boundary layer, 21 cm of overlying mudstone, and lower units but not units above the mudstone. Triggering at this locality was delayed until after the mudstone was deposited. Both sites were likely in the tensional flexural bulge of the Sangre de Cristo thrust system at the end of the Cretaceous period.