YPF

Abstract: Argentina’s San Jorge Basin, which straddles the southern provinces of Chubut and Santa Cruz in the heart of Patagonia, has been producing hydrocarbons since 1907. The region currently accounts for 32% of the country’s production. The existence and early geologic evolution of the basin is due to the same rift process responsible for the opening of the Atlantic Ocean in early Jurassic times. Extensive direct faulting and local erosion accompanied the rift evolution, thereby facilitating the accumulation of chiefly nonmarine terrigenous sediments well into the early Cretaceous. At this point, Andean tectonism became a major source of pyroclastic concentration in the sedimentary column; it was also responsible for pervasive batholitic intrusions. Clastic deposition in the hydrocarbon‐producing zone is characterized by thick shale laminations of lacustrine and floodplain origin, interspersed with much thinner and laterally sparse sand bodies (the hydrocarbon reservoirs).

Abstract: The Rio Grande and Palauco Cenozoic basin: Age, evolution and structural control, Malargue fold-belt (36°S) The Palauco and Rio Grande valley area at 36° south latitude is part of the Malargue fold-belt in southern Cordillera Principal The Cenozoic tectonic evolution of this area was recorded by volcaniclastic sediments deposited in syntectonic basins The structural con- figuration of basement-involved structures at this latitude, defines an internal part where the Rio Grande sub-basin was de- veloped and a frontal part where Palauco sub-basin was paced The filling of these basins shows a pre-growth stage domina- ted by basaltic sequences that was present up to about 23 Ma From 18 Ma with the uplift of the main structures, each sub- basin evolved in an independent way Therefore, the western part of Rio Grande sub-basin was fed by coarse proximal facies related to the uplift of the Sierra Azul anticline, while the distal fine-sediments and evaporates located in the eastern part of the basin wedged-up against Pampa Paluco-Ranquil Co anticline, showing that this structure was already an internal barrier This stage finished approximately at 11 Ma, age from which both sub basins show again a similar filling dominated by volca- nic deposits present in the whole area During this new stage, different events of reactivation of the Pampa Palauco-Ranquil Co anticline were recorded by angular unconformities observed in the field, which were constrained at 11 Ma and 8 Ma from radiometric determinations These events also have generated the development of the new deformation front to the east, with the uplift of the Cerro Fortunoso, Loma Amarilla and Rincon Colorido anticlines, giving the definitive configuration to the basin