Revisiting the paleogeographic framework of northeastern Gondwana in the late Paleozoic: Implications from detrital zircon analysis

Abstract

The Baoshan, Tengchong, Lhasa, South Qiangtang, and Sibumasu terranes were part of Gondwana prior to rifting and drifting from the northern margin since the Early Permian. However, paleopositions of these terranes during the late Paleozoic remain controversial, which hinders better understanding the tectonic evolution of the Paleo-Tethys and glacier distribution patterns on eastern Gondwana during the late Paleozoic ice age. As robust provenance indicators, detrital zircon U–Pb dating and Hf isotope signatures have been widely utilized in paleogeographic reconstruction. Here, we collected a total of 8209 detrital zircon U–Pb ages and 1606 zircon Hf isotopic values from Paleozoic strata of northeastern Gondwana. These data are utilized to evaluate their paleopositions relative to Australian and Indian Gondwana through semi-quantitative data analysis. Our new paleogeographic model indicates that the South Qiangtang, Baoshan, and part of Sibumasu were outboard of the northern margin of Indian Gondwana during the Paleozoic, whereas the Lhasa and Sumatra terranes were located along the northern margin of Australia. Based on provenance shifts of late Paleozoic glaciogenic sedimentary rocks in northeastern Gondwana, two main ice sheets are hypothesized to have developed during the late Paleozoic. This study further confirms the model of a multicenter glacier distribution pattern on Gondwana during the late Paleozoic ice age from a perspective of provenance.