Stratigraphy and sedimentology of Quebrada de Arca Yaco (Tolombón, Salta province, Argentina)

Abstract

Stratigraphy and sedimentology of Quebrada de Arca Yaco (Tolombón, Salta province, Argentina)?. The area is covered with outcrops of the Santa María Group (Miocene-Pliocene), the Yacomisqui Formation (Upper Cretaceous and the Puncoviscana Formation (Precam.-Lower Camb.? ). The latter forms the metamorphic basement of the Sierra de Santa Bárbara, which is the extension of the Cumbres Calchaquíes. The Santa María Group was deposited under marine-continental conditions as revealed by the fossils therein found and sedimentary textures and structures observed. The Angastaco Formation in the Valle Calchaquí is considered equivalent to the Andalhuala Formation (Santa María Group) which crops out in the homonymous valley. In the same way the Yacomisqui Formation is considered correlatable with Los Blanquitos Formation (Pirgua Subgroup).