Lithosphere thickness in the Gulf of California region

The Gulf of California has a long tectonic history. Before the subduction of the Guadalupe and Magdalena plates ceased, extension of the Gulf began to the east, at the Basin and Range province. Later, it was focused west of the Sierra Madre Occidental and the opening of the Gulf started. Currently, the Gulf rifting has different characteristics to the north than to the south. In this study, we analyze the lithosphere thickness in the Gulf of California region by means of P -wave and S -wave receiver functions. We grouped our lithosphere-thickness estimates into five froups: 1) North of the Gulf, with a thin lithosphere (~ 50 km) related to the extension observed in the Salton Through region; 2) the northwestern part of Baja California, with a thicker lithosphere (~ 80 km), thinning towards the Gulf due to the extension and opening processes (~ 65 km); 3) central Baja California, with no converted phase corresponding to the lithosphere-asthenosphere boundary but evidence of the presence of a slab remnant; 4) the southern Baja California peninsula, showing a shallow lithosphere-astenosphere boundary (LAB) (