Resultados paleomagnéticos preliminares en el vulcanismo neógeno de la Sierra de Las Cruces (Valle de México, México)

Abstract

A palaeomagnétic study have been carried out on the western margin of the México basin. 24 sites from Sierra de Las Cruces were sampled and analyzed in the laboratory. A total amount of 237 samples has been fully demagnetized and a simple directional magnetic behavior was observed in all samples. The mean direction obtained in this study is D = 3 5 3 .1 1=31.6 ( N = 2 4 K = 2 8 .9 a 9 5 = 5 .6 ), in agreement with the expected direction. Therefore this area has not been affected by significant block rotations in contrast to the counterclockwise rotations observed in the easternmost sector of the Transmexican Volcanic Belt (TMVB), towards the Gulf of México, and in its centrahwestem part. In addition a magnetic zonation has been observed covering at least the Matuyama and Gauss polarity chrons