Successive reactivation of older structures under variable heat flow conditions evidenced by K-Ar fault gouge dating in Sierra de Ambato, northern Argentine broken foreland

NOBILE, J.C, COLLO, G., DÁVILA, F.M., MARTINA, F. WEMMER, K.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 64 p. 152 - 165

0895-9811

The Argentine broken foreland has been the subject of continuous research to determine the uplift andexhumation history of the region. High-elevation mountains are the result of NeS reverse faults thatdisrupted a WeE Miocene Andean foreland basin. In the Sierra de Ambato (northern Argentine brokenforeland) the reverse faults offset Neogene sedimentary rocks (Aconquija Fm., ~9 Ma) and affect thebasement comprising Paleozoic metamorphic rocks that have been dated at ~477470 Ma. In order toestablish a chronology of these faults affecting the previous continuous basin we date the formation ageof clay minerals associated with fault gouge using the KeAr dating technique. Clay mineral formation is afundamental process in the evolution of faults under the brittle regime (