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大陆架科学钻探CSDP-2井,是南黄海中部隆起上的唯一深钻,是揭示中-古生代海相地层时代,恢复沉积和构造环境的基准井。菊石是二叠纪至三叠纪的重要古生物,在指示地层时代和恢复古地理环境方面,都具有重要价值。在CSDP-2井岩心中发现多块菊石化石,其中的两块化石具有重要意义。根据菊石形态特征,取自1 475.2m岩心中的Roadoceras cf.sinense时代被鉴定为二叠纪罗德阶(Roadian)—吴家坪阶(Wuchiapingian),属于近20年来建立起来的菊石属Roadoceras,其古地理分布位于古赤道及双温区,此次发现的样品则来自华南北缘,拓展了该属的古地理分布范围。另外,在851.9m处岩心中,发现了蛇菊石Ophiceratidae,其为早三叠世格里斯巴赫阶(Griesbachian)分子,非常接近三叠系的底部,为CSDP-2井二叠纪和三叠纪界线的划分提供了重要证据。上述菊石的发现,有助于厘定南黄海中部隆起二叠系-三叠系海相地层发育时代,恢复古地理环境,亦为南黄海进一步的沉积、构造和油气资源研究奠定重要基础。
The Continental Scientific Drilling CSDP-2 well, the only deep drill on the uplift of the southern South Yellow Sea, is the reference well that revealed the Meso-Paleozoic marine strata era, restoring sedimentation and tectonic setting. Ammonites are important Palaeozoic from the Permian to Triassic, and are of great value in indicating the age of the formation and restoring the paleogeographic environment. In the core of CSDP-2, more than one ammonite fossil was found, two of which are of great significance. According to the morphological characteristics of the ammonites, the Roadoceras cf.sinense epoch taken from a 1,475.2-m core was identified as the Permian Roadian-Wuchiapingian, belonging to the established Roadoceras of the past two decades, Geographical distribution is located in the ancient equator and dual temperature zone, the sample was found from the northern margin of South China, expanding the Palaeogeographical distribution. In addition, Ophiceratidae, an Early Triassic Griesbachian molecule, was found in the core of 851.9 m, very close to the bottom of the Triassic, and was the Permian and Triassic of the CSDP-2 well Dividing the boundaries provides important evidence. The discovery of the above ammonites can help to determine the development age of the Permian-Triassic marine strata in the southern part of the southern Yellow Sea and restore the paleogeographic environment. It also lays an important foundation for further sedimentation, structure and oil and gas resources research in the southern Yellow Sea.