Drainage reorganization and tectonic deformation in the Chaschuil and Fiambalá basins of NW Argentina
Abstract
Drainage networks reflect the interaction of surface processes and tectonics and studying their planform evolution and channel response can aid in elucidating patterns of tectonic deformation. Additionally, as drainage networks dictate sediment provenance and influence sedimentary budgets, a nuanced understanding of their evolution is important for sedimentological studies. Features indicative of regional drainage reorganization include wind gaps and associated knickpoints, barbed drainage and hairpin turns, drainage divide migration, and deflected channels. Intermontane basins and their associated basin bounding ranges around the Puna Plateau in NW Argentina are excellent recorders of this process due to low out-of-channel erosion rates, limited glaciation, and a relatively stable long-term climate. The two intermontane basins assessed in this study, Chaschuil and Fiambalá, are located at the southern margin of the Puna Plateau, in the high-angle reverse fault bound ranges of the Sierras Pampeanas. We use systematic analysis of planform drainage, river long profiles, and other geomorphic features to identify signs of drainage reorganization and links to regional tectonic deformation. Evidence of drainage capture in Chaschuil, including a hairpin turn, barbed drainage, and knickpoints, suggests that the original N-S drainage and east-bounding ranges, Sierra de las Planchadas and Sierra de Narvaez, are being dissected by headward erosion and rivers are diverted east into Fiambalá. In southern Fiambalá, a wind gap and deflected river indicate that the east-bounding range, Sierra de Fiambalá, is propagating south. The implications of the above drainage reorganizations are discussed in the context of regional Cenozoic deformation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMEP53C0975S
- Keywords:
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- 1824 Geomorphology: general;
- HYDROLOGYDE: 1825 Geomorphology: fluvial;
- HYDROLOGYDE: 1826 Geomorphology: hillslope;
- HYDROLOGYDE: 1886 Weathering;
- HYDROLOGY