Andean reactivation of the Cretaceous Salta rift, northwestern Argentina

Tectonics, Climate, and Landscape Evolution of the Southern Central Andes: the Argentine Puna Plateau and Adjacent Regions between 22 and 30°S

“…Our field studies and theoretical analyses indicate, however that the nature of this coupling may also vary strongly depending on the pre-orogenic geologic history. This is emphasized by the width of the present Puna Plateau and the adjacent tectonic provinces and their relation to the Cretaceous Salta Rift (e.g., Allmendinger et al 1983;Grier et al 1991;Kley and Monaldi 2002;Kley et al 2005;Mon et al 2005;) and those structures within the present plateau that were generated during a different subduction regime in Oligocene time (e.g., Kay et al 1999;Kraemer et al 1999;Carrapa et al 2005). The width of these tectonic provinces in the Central Andes is thus a first-order result of structural inheritance and tectonic conditions and may not be primarily a function of the arid climate, as envisioned by Montgomery et al (2001).…”

“…12.3), Anzótegui (1998) and Starck and Anzótegui (2001) describe an arid paleoenvironment at approximately 13.4 ± 0.4 Ma (Grier et al 1991), which heralds the deposition of the coarse sandstones of the Angastaco Formation in this intramontane basin near the village of Angastaco. These conditions were followed by the deposition of sandstones and siltstones rich in organic material during more humid conditions that were dominated by fluvial and lacustrine sedimentary environments recorded in the Palo Pintado formation by about 5.4 Ma (Starck and Anzóteguí 2001;Coutand et al 2006).…”

“…These sedimentary basins are presently internally drained and contain thick sequences of continental evaporites and clastic deposits (Jordan and Alonso 1987;Alonso et al 1991). Contraction in the region of the present-day plateau and adjacent areas in the Eastern Cordillera and the northern Sierras Pampeanas has apparently contributed to the formation of closed depocenters on the present plateau and transiently closed intramontane basins within the other tectonic provinces of northwestern Argentina Alonso et al 1991;Grier et al 1991;Kraemer et al 1999;Coutand et al 2001;Marrett and Strecker 2000;Bossi et al 2001;Carrapa et al 2005). Jordan et al (1983) The Eastern Cordillera comprises a region of late Proterozoic to early Paleozoic metasedimentary and intrusive rocks (e.g., Jezek et al 1985;Omarini 1983) that were uplifted along bivergent, north-northeast striking thrust faults, which were largely responsible for the deformation of Neogene intramontane and foreland sedimentary sequences (Mon and Salfity 1995).…”

“…In the northern and central portion of this area east of the Cordillera Oriental, the Santa Barbara thrust belt involves Precambrian metagreywackes and Cretaceous and Tertiary sediments. These units are deformed by reverse faulting along preexisting Cretaceous normal faults that define the southern termination of the Cretaceous Salta continental rift basin (e.g., Grier et al 1991;Kley and Monaldi 2002;Kley et al 2005;Marquillas et al 2005;Gonzáles and Mon 1996;Mon et al 2005).…”

“…The Angastaco Basin lies southeast of the Puna margin within the transition between the northern Sierras Pampeanas, the Santa Barbara System and the Cordillera Oriental at 25°30' S ( Fig. 12.3), and preserves a sedimentary sequence in excess of 6 km thickness and spanning the interval from 13.4 to 2.4 Ma (Grier et al 1991;Strecker, unpub. data 2005).…”