| Description |
-
The relative timing of tectonic uplifts in the Sierras Pampeanas in western Argentina is poorly understood. The purpose of this study is to constrain the timing of uplift of the mountains around the Pipanaco Basin in this region through zircon geochronology. Basin stratigraphy represents a braided fluvial system with three interbedded volcanic ash-fall units, and is identified as part of the Toro ... read moreNegro Formation. Zircon ages obtained from the ash samples indicate a depositional age of 3.0167 +/- 0.12 Ma (Late Pliocene); related uplifts in the Pipanaco Basin are interpreted to have occurred just prior to deposition. This age, coupled with basin stratigraphy, indicates that the deposits interbedded with the ash samples are from regional Sierras Pampeanas sources and are not related to a typical, unbroken foreland basin system associated with the Cordillera of the Andes. The lack of traditional foreland basin deposits, coupled with a paucity of Cenozoic outcrops that correspond to the timing of Cordilleran uplift, indicates a likely paleo-topographic high that prevented sedimentation in this region from Andean Cordillera sources.read less
|
|---|
This object is in collection
