Thermochronometric data on the development of the basement peneplain in the Sierras Pampeanas, Argentina

Abstract

In the Sierras Pampeanas geomorphic province of central Argentina there are regions where exposed crystalline basement has had no sedimentary cover older than Neogene strata, and other areas where upper Paleozoic and Mesozoic strata overlie the basement. Both types of areas are characterized by a smooth upper basement surface, which has been interpreted as a peneplain that has been deformed and exhumed during the Neogene. The history of generation of the basement peneplain can be determined from thermochronometric and stratigraphic data. This reconnaissance study produced new data on the cooling history of rocks from seven sites in the Sierras Pampeanas. Fission-track cooling ages of apatite..