Revisiting the paleogeographic position of South China in Gondwana by geochemistry and U Pb ages of detrital monazite grains from Cambrian sedimentary rocks

Abstract

South China is placed in a range of positions along the northern margin of East Gondwana in the early Paleozoic reflecting uncertainties in linking U Pb ages of detrital zircon to potential sources. Using detrital monazite U Pb ages from Cambrian sedimentary rocks, we argue for a position outboard of northeastern India. Detrital monazite yields predominantly earliest Neoproterozoic and earliest Cambrian age peaks at circa 945 Ma and 528 Ma, with minor end Mesoproterozoic and late Paleoproterozoic to early Mesoproterozoic ages. Compared with the U Pb age distribution pattern of detrital zircon from the same samples, the monazite data highlights input from earliest Cambrian metapelites. These earliest Neoproterozoic and earliest Cambrian detrital monazite grains match with ages and Th and U contents of monazite from northeastern India, but are different from those from northwestern India and northern Australia, and thus enable tighter constraints on the paleogeography of South China than detrital zircon data alone. • U Pb ages of detrital monazite from the Cambrian sandstones in the southern part of South China are analyzed. • Cambrian detrital monazite from the southern part of South China yields predominantly age peaks at circa 945 Ma and 530 Ma. • South China was linked to the northeastern India margin of East Gondwana in the Cambrian. • Detrital monazite can provide a more accurate record of provenance than detrital zircon.