TY  - JOUR
A1  - Pingel, Heiko
A1  - Schildgen, Taylor F.
A1  - Strecker, Manfred
A1  - Wittmann, Hella
T1  - Pliocene-Pleistocene orographic control on denudation in northwest Argentina
T2  - Geology
N2  - The intermontane Humahuaca Basin in the Eastern Cordillera of the northwest Argentine Andes lies leeward of an orographic barrier to easterly derived moisture. An average of >2000 mm/yr of rainfall along the eastern flanks of the barrier contrasts with <200 mm/yr in the orogen interior. Paleoenvironmental reconstructions suggest that the basin became disconnected from the foreland during the Miocene-Pliocene by the growth of fault-bounded mountain ranges. Fossil records, sedimentology, and stable isotope data imply that rerouting of the fluvial network by 4.2 Ma and reduced rainfall by ca. 3 Ma were consequences of that range uplift. Here, we present cosmogenic nuclide-derived (Be-10) paleodenudation rates from 6 to 2 Ma fluvial deposits collected from the Humahuaca Basin. Despite increased tectonic activity, our Be-10 data show a tenfold decrease in denudation rates at ca. 3 Ma, documenting a link between uplift-induced semiarid conditions and decreasing hillslope denudation rates. This new data set thus demonstrates the influence of hydrological change on spatiotemporal denudation patterns in tectonically active mountain areas.
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/49860
SN  - 0091-7613
SN  - 1943-2682
VL  - 47
IS  - 4
SP  - 359
EP  - 362
PB  - American Institute of Physics
CY  - Boulder
ER  -