Paleogeographic Reconstruction of the Paleozoic Lhasa Terrane Through Detrital Zircon Mixing Modeling

A late Mesoproterozoic detrital zircon (DZ) age population, which was previously considered diagnostic of a link between the Lhasa terrane and northwest Australia, occurs in other Gondwanan components, thus obscuring the paleogeographic position of the Lhasa terrane in Gondwana. Here we compiled large-n (n >= 300) DZ U-Pb data from the Lhasa terrane and potential source regions in various proposed reconstructions, and attempted to synthesize the Lhasa DZ age spectra through DZ mixing modeling. Our modeling results support the Permo-Carboniferous Lhasa terrane having received sediment from NW Australia (mainly the Perth basin) rather than India or Africa. This, in combination with stratigraphic and paleontological evidence from the northern margin of eastern Gondwana positions the Paleozoic Lhasa terrane adjacent to the boundary between Australia and India. This study suggests that the DZ mixing modeling method based on large-n DZ data can be used effectively for constraining paleogeographic reconstruction of continents.

Automated summary

This study uses large sample zircon age data and mixing modeling method to investigate the paleogeographic position of the Lhasa terrane. The results suggest that during the Permo-Carboniferous, the Lhasa terrane received sediment from northwest Australia, aligning with stratigraphic and paleontological evidence from the northern margin of eastern Gondwana. The study highlights the effectiveness of the DZ mixing modeling method in constraining paleogeographic reconstruction.