Sedimentary aspects and paleoenvironmental evoluti

Authors: Rosa A Marquillas Cecilia del Papa Ignacio F Sabino

Publish Date: 2004/10/21

Volume: 94, Issue: 1, Pages: 94-113

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Abstract

The rift history of the Salta basin is related to the evolution of the Central Andes and to the activity of the Pacific margin owing to its geographic location Sedimentation occurred from the Neocomian to the Paleogene with deposits reaching up to 5000 m in thickness Paleoenvironmental analysis reveals an evolutionary history controlled by tectonic and climatic changes Isolated grabens characterized the early synrift stage differential subsidence provoked distinct environments in the southern and northern subbasins In the southern subbasins alluvialfan fluvialfan and lacustrine deposits prevail whilst in the northern subbasins eolian and fluvial environments dominate During the Maastrichtian two major factors controlled the basin fill the decrease in tectonic subsidence and a relative sealevel rise as recorded in South America An extensive and shallow Atlantic marine ingression installed a carbonate system coincident with mainly humid conditions until the Danian Until the Middle Eocene the fluvial and lacustrine environmental evolution of the sag basin was controlled especially by the alternation of temperate with dry and humid periods Paleontological records reflect these climatic changes and show their relationship to the sedimentation regimeThis study was supported by the grants PIPCONICET 0883 RM PEI 6091CdP PICTANPCyT 12419 RM and 12492 IS of Argentina also by grants CIUNSa Universidad Nacional de Salta Argentina 1220 RM and 1281 IS We acknowledge Dr José A Salfity’s and Dr Wolfgang Volkheimer’s constant support and valuable advice We are grateful to the reviewers Prof Andreas Schäfer and Prof Heinrich Bahlburg for their constructive comments on the manuscript

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