MIDDLE PERMIAN TELODIAGENETIC PROCESSES IN NEOPROTEROZOIC SEQUENCES, TANDILIA SYSTEM, ARGENTINA

PATRICIA EUGENIA ZALBA, MARCELO MANASSERO, EMMANUEL LAVERRET DANIEL BEAUFORT, ALAIN MEUNIER, MARTÍN MOROSI AND LAURA SEGOVIA

Journal of Sedimentary Research

SEMP Society for Sedimentary Geology

Lugar: Boulder, Colorado; Año: 2006

1527-1404

In the Tandilia Basin, Buenos Aires Province, Argentina, we study the genesis of mud beds and pipes in the Loma Negra Formation (limestones), Sierras Bayas area, together with the emplacement of alunite and aluminum phosphate sulfate (APS) minerals in the Las Aguilas Formation, Barker area. All these features are related to basin inversion, uplift, erosion, and injection/expulsion or infiltration of fluids and oxidation reactions in the exhumed rocks during a telodiagenetic stage. On the basis of K-Ar dating of alunite in the Las Aguilas Formation (claystones) giving an age of 254 ± 7 Ma (middle Permian), these processes are considered to be linked to a major geological event which affected these Neoproterozoic lithostratigraphic units: the folding of the Ventania System, located 150 km to the SW of the study area.