The varved sediments of JiangCo (IMAGE) Science China Press Caption The varves of JiangCo are annual varves, each layer divided into coarse-grained and fine-grained sub-layers Credit ©Science China Press Usage Restrictions Use with credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.