During the Early Silurian the Yangtze Platform of the South China Block was mainly covered by terrigenous sediments derived from the surrounding land, which was then being uplifted. The palaeogeographic setting of the Hanchiatien Formation (lower Telychian, Llandovery, Lower Silurian) indicates a seaward ramp oriented northwards, with a nearby shoal belt spanning northern Guizhou and southern Sichuan. The unit was dominated lithologically by muddy and silty sediments. A sporadic supply of siliciclastic debris enhanced turbidity, resulting in an environment unsuitable for development of a large scale carbonate platform. However, a benthic assemblage of the brachiopods Nalivkinia and Striispirifer indicates a palaeodepth (BA2) which was above the fair weather base and was favourable for reef and bank formation.