The Paleogene- Neogene succession i

The Paleogene- Neogene succession is approximately 10,000 m thick, includes sandstones and mudstones with minor coal and limestone intervals (Yang et al., 2011), and is overlain by Quaternary clays and mudstones (Fig. 2a). Sediments deposited at the synrift stage were restricted to grabens and half-grabens and were composed of the Shimentan, Lingfeng, Mingyuefeng, Oujiang, and Pinghu Formations. The Shimentan Formation was deposited in alluvial-fluvial-lacustrine environments whilst the Lingfeng, Mingyuefeng, and Oujiang Formations were shallow marine deposits with the Pinghu Formation dominated by fjord-tidal flat deposits. The postrift stage is characterized by deposition of the Huagang, Longjing, Yuquan, Liulang, and SantanFormations. Sediments of these formations were predominantly fluvialdelta-lacustrine deposits (Fig. 2A).