Petrochemical constraints on the emplacement of Paleocene Porphyry copper deposits in Antofagasta Region (Chile) in response to regional stress changes

Abstract

Margin configuration and tectonic evolution of the Andean region of northern Chile during Paleocene rime is not yer well understood in detail. There is a general agreement, however, for a low to very low convergenc rate an a highly oblique direction between the Farallon and the South American plates for most of the Paleocene. The dominant tectonic regime of the Paleocen time is commonly described as extensional or transtentional. The nature and geometry of the resulting plate margin, howeves, is less clear. It has been subject to different interpretations, which range from an active subduccion margin associated to arc migration (Coira et al. 1982, Mpodozis and Ramos 1990) to the development of a transform margin (Aragón et al 2011).