(Phys.org)—A team of researchers with the University of Wisconsin, Berkeley and the New Mexico Institute of Mining and Technology has used U-Th testing of coseismic calcite veins at the Loma Blanc fault in New Mexico to learn the earthquake history of the fault going back almost a half-million years. In their paper published in Proceedings of the National Academy of Sciences, the group describes their study and their assembly of the longest seismic record ever made of any fault in the world.