The coupling of the Shidian uplift and the Cambrian carbonate platform in the central part of the Baoshan block, western Yunnan

In the 1:50 000 regional geological surveying several years ago, the authors collected abundant plalaeontological fossils in the Baoshan block, and confirmed that the Early Ordovician deposits are absent, and there is a parallel unconformity between the Ordovician strata and Cambrian strata in the Shidian region. The preliminary delineation of the extent of the Shidian uplift during the Early Ordovician coincides with that of the Late Cambrian carbonate platform in the Shidian region. This uplift resulted from double controlling factors of both the crustal uplifting and sea-level falling, especially the rapidly uplifting of the Late Cambrian carbonate platform. The proposition and delineation of the terminology Shidian uplift may have important implications for the better understanding of the tectonic evolution of the Baoshan block during the Early Palaeozoic.