Mesozoic tectonic in the deposition and evolution of Cretaceous sedimentary packages of the Parecis Basin, center-western Brazil

摘要

The Cretaceous record of the Parecis Basin (central western Brazil) consists of two sedimentary packages with distinct depositional signatures, physically discontinuous, and deposited in two depocenters in the east and west of Serra Formosa Arch. The basin evolved during the Mesozoic age and includes a regional record with volcanism, tectonism, deposition and uplift with erosion. During the Upper Triassic and Lower Jurassic, volcanism and sedimentation occurred, which were followed by uplift and erosion until the Lower Cretaceous, moment in which basic and alkaline magmatism was present. Since the Upper Cretaceous, with the beginning of the compressive phase of Andean Orogeny and opening of the Atlantic Ocean, tectonism and sedimentation were developed in the Juruena Sub-basin during the Cenomanian and in the Xingu Sub-basin from the upper Coniacian. Based on facies association and regional surface recognition, a differential depositional signature was identified for each sedimentary package, influenced by the activity and behavior of the internal sub-basins. In the Juruena Sub-basin, fluvial and aeolian sedimentary package were deposited with sedimentation rates higher than that of subsidence. In the Alto Xingu Sub-basin, a sedimentary package is here named the Rio Tapirape Formation and includes a lacustrine system that was established with an overpass of the subsidence rate in relation to the sedimentation rate. Toward the top, it was replaced by a fluvial and deltaic sedimentary system, with the decrease in the subsidence rate.