Plate tectonics in the Gulf of California: back to the beginning.

Jose Javier Gonzalez-Garcia

Submitted September 11, 2022, SCEC Contribution #12308, 2022 SCEC Annual Meeting Poster #075

From the beginning of the geometric formulation of the theory of Plate Tectonics the Gulf of California was considered as a substantive source of data. Going back, I use the model Geodvel (Argus, 2010) for the boundary between the North American and Pacific plates with a slightly modified Euler pole(geographical coordinates: 50.535*n, 75.065*w, 0.7767*/Ma), in order to determine the evolution of the opening of the Gulf of California and the Salton Trough. Four major transform fault sectors are necessary to attempt it: East San Andres-Salton Sea (34.24*), West San Andres-Ballenas (35.71*), Tamayo (37.66*) and Tosco/Abreojos-Istmo (38.95*) where the value between parenthesis is its colatitude. The opening of the mouth of the gulf between Tamayo and Tosco/Abreojos starts 8.63 Ma ago; between San Andres east and Ballenas the island Angel de la Guarda is attached to the peninsula 2.47 Ma ago and Tiburon 5.06 Ma ago. This value differs from the 6.3 Ma proposed by Oskin and Stock (2003); our result fits their if we apply the velocity of 40.5 mm/yr obtained with GPS between Hermosillo, Son. and San Felipe, B.C. corresponding to 81% of model velocity. However, these authors match the age of the younger rocks with the beginning of the separation, and this may not be able to be corroborated. I hope to present some preliminary results for the Salton Trough.

Key Words
Gulf of California, Geodvel, San Andreas Fault, Plate Tectonics

Gonzalez-Garcia, J. (2022, 09). Plate tectonics in the Gulf of California: back to the beginning.. Poster Presentation at 2022 SCEC Annual Meeting.

Related Projects & Working Groups
Tectonic Geodesy