Magnetoestratigrafía volcánica de Ia zona geotérmica Ixtlan de los Hervores-Los Negritos, Michoacán, Mexico: Resultados preliminares

Abstract

Preliminary results of a study comprising paleomagnetism (magnetostratigraphy from fourteen sites), radiometric K-Ar dating (five dates) and field reconnaissance surveys in the geothermal area of lxtlan de los Hervores-Los Negritos, Michoacan, Mexico are presented. Volcanic activity covers an interval extending from chron 8 (Late Miocene, K-Ar date 8.8 ± 0.8 Ma) to the Recent Brunhes chron. Most units correspond to the Matuyama reverse chron, (0.73 to 2.48 Ma). Normal polarity is observed for two sites within the reverse Matuyama chron. From polarity and a K-Ar date of 2.0 ± 0.2 Ma, this may correspond to the Reunion normal polarity subchrons (2.01-2.04 Ma and 2.12-2.14 Ma).