Permian depositional age of metaturbidites of the Duque de York Complex, southern Chile: U-Pb SHRIMP data and palynology.

Abstract

The Duque de York Complex (DYC) is part ofthe low grade metamorphic accretionary complexes ofthe pre-Andean Patagonian 'basement'. lt is a sedimentary succession exposed along the westem margin of southemmost South America. New U-Pb zircon ages and palynological data restrict the maximum depositional age ofthe DYC to the limit between the early Permian (Kungurian) and the middle Permian (Roadian). The palynological association recorded in the DYC, characterized mainly by Gymnospermopsida pollen, indicates ahumid environment offorestwith an undergrowth offerns. Regional paleogeographic correlations point out that an interpretation ofDYC asan autochthonous terrane cannot be discarded, contrasting with previous hypotheses which suggest an allochthonous character for this complex.