Thermal post-depositional evolution of the Neoproterozoic-Paleozoic pelites of the northwest Argentina and their implications for the early Paleozoic evolution of the SW Gondwana margin

PAMELA ALEJANDRA APARICIO GONZÁLEZ; CLAUDIO DE MORISSON VALERIANO; REIMOLD, W; ANDREA BARRIENTOS; NATALIA HAUSER; AGNES IMPICCINI; MONICA HEILBRON

General Roca

Otro; XVI Reunión Argentina de Sedimentología; 2018

Asociación Argentina de Sedimentología

A comparative analysis of the thermal post-depositional evolution ofmetapelitic of the Paleozoic succession (Puncoviscana Complex (PC), SantaVictoria and Mesón Groups) in the Central Andes of northwestern Argentina wasestimated through Xray diffraction of clay minerals analysis and Kübler Index (KI).The results indicate variation between diagenetic-epizone grade for the southNeoproterozoic ? Lower Paleozoic succession. This results are similar known inthe north of Cordillera indicate that the diagenesis-metamorphic grade is uniformityfor the Cordillera Oriental. XRD-based studies of metapelitic rocks of the Paleozoicsequence indicate the presence of illite, mica/chlorite, kaolinite andchlorite/smectite. The origin of the clay minerals could be associated to volcanicash and others probable indicate retrograde reactions. Probable k-bentonite wasidentified in white-yellow layers of the pelite of the San Bernardo Formation(Tremadocian-Flonian) associate with the Faja eruptiva de la Puna.