Neogene reactivation of older structures evidenced by K?Ar fault gouge dating in northern Argentine broken foreland

NÓBILE, JULIETA; COLLO, GILDA; DÁVILA, FEDERICO M.; MARTINA, FEDERICO; WEMMER, KLAUS

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015

0895-9811

The Argentine broken foreland has been the subject of continuous research to determine the uplift and exhumation history of the region. High-elevation mountains are the result of N?S reverse faults that disrupted a W?E Miocene Andean foreland basin. In the Sierra de Ambato (northern Argentine broken foreland) the reverse faults offset Neogene sedimentary rocks (Aconquija Fm., ∼9 Ma) and affect the basement comprising Paleozoic metamorphic rocks that have been dated at ∼477−470 Ma. In order to establish a chronology of these faults affecting the previous continuous basin we date the formation age of clay minerals associated with fault gouge using the K?Ar dating technique. Clay mineral formation is a fundamental process in the evolution of faults under the brittle regime (