Carbon, oxygen and strontium isotopic composition of low-latitude Permian carbonates (Venezuelan Andes): climate proxies of tropical Pangea

Abstract

AbstractThe Late Palaeozoic period was an important time in Earth history, primarily as a result of the formation of Pangea and the Gondwana glaciations that had direct influences in high latitudes and indirect, but no less important, effects in low latitudes. This study documents and interprets the isotopic record for the Early–Middle Permian in northern Gondwana from detailed fieldwork in the Venezuelan Andes. Sr-isotope dating of well-preserved brachiopod shells suggests a Kungurian age from samples located within the middle part of the Palmarito Formation. δ13C data show a long-term trend through the section towards more positive values, but with some very negative δ13C values suggesting carbonates affected by pedogenic processes. In the middle part of the succession, major excursions in δ13C and δ18O show a strong connection with glacial–deglacial events during the Early–Middle Permian. Overall results presented here fill an important gap in the regional palaeogeography and, therefore, have significant implications for the palaeoclimate and palaeoceanography of this Late Palaeozoic time.