Interaction between neotectonic and surface processes in a low-land midcontinent setting of South America

BRUNETTO, ERNESTO

Plymouth

Conferencia; Centre for Research in Earth Science annual research conference (CRES Conference 2015); 18/11/2015. School of Geography, Earth and Environmental Sciences - Plymouth University; 2015

School of Geography, Earth and Environmental Sciences - Plymouth University

The interiors of continents are typically considered to be tectonically inactive. For this reason, the Quaternary sedimentary record in such settings has mainly been studied from a climatic perspective in relation to weathering, flood hydrology and sedimentary basin flux. However, in intracratonic basins, where sedimentary accumulation corresponds to a long-term subsidence history (10Ma-100Ma), evidence for Quaternary tectonism is generally dismissed. The large Pampean plains region of Argentina offers an interesting example to assess the relative effect of different factors controlling erosion/ sedimentation on the landscape evolution in continental interiors. Evidence of recent tectonics over intermediate time scales (10ka - 200ka) suggests a rapid evolution in elevated basin margin areas that surround the regionally extensive sedimentary plains. Geomorphologic modelling constrained from stratigraphic and structural data suggests that deformation rates can be higher than previously considered in such geological settings. This approach also provides new conceptual insights into the long term drainage evolution within intracratonic regions. It also, provides a first step in the characterization of potential seismogenic sources in an area that is generally considered to be stable.