Tracing the volcanic and tectonic effects of the Miocene Andean stage along the Patagonian retroarc: an example of the Río Negro system, Argentina

Abstract

The Río Negro River system constitutes a drainage network located at the North Patagonian Region (45°S) that connected the Andes with the Atlantic Ocean through more than 600 km long. This corridor is one of the systems that control the transference of materials to submarine shelf, up to sink position, in the Argentina basin. During the Neogene this system was configured in a scenario of profuse arc-explosive volcanism, contractional tilt-block tectonics, the development of the orogenic rain shadow, as well as relative sea level changes. Several fault-bounded exoreic-closed-basins along the retroarc present infill that record endogenous and superficial processes occurred during the birth of the Andean chain, at this latitude, as we observe it today. Even though time-spatial large scale stratigraphic units and holistic geological models were performed to go forward in the understanding of the system, until now are absent high resolution tectonic-volcano-climatic-eustatic models that allow to understand the sediment supply/accommodation space relationship and the reciprocal stratigraphical effects along the whole system, in which the propagation of the environmental signals be consider. Based on a multidisciplinary approach, which includes structural, stratigraphic, geomorphological and geochronological dataset together with previous surface and subsurface regional surveys, the analysis retroarc basin along Río Negro system is carrying out.