Was there a Cambrian ocean in South China? – Insight from detrital provenance analyses

Abstract

We use detrital provenance data from Cambrian sandstones to examine whether the Yangtze and Cathaysia blocks in South China were separated by an ocean during the Cambrian period. Zircons from the Cambrian sandstones exhibit a dominant ~800 Ma age peak in the central Yangtze Block, being sourced from the western Yangtze Block, whereas a ~980 Ma peak dominates in the northwestern Cathaysia Block, being sourced from an exotic continent once connected to Cathaysia. A mixed provenance with both age peaks is found in Cambrian sandstones from the southeastern Yangtze Block, indicating that detritus can travel from the Cathaysia Block to the Yangtze Block, and therefore arguing against the existence of a broad Cambrian ocean.