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本文在龙门山雁门坝泥盆系剖面下中统交界区划分出4个腕足化石带。依据现代地层学原则,将下中统界线确定在甘溪组顶部,以Xenospirifer fongi的首次出现为标志,此界线与国际界线层型相当。文中提出了在无指定化石带地区确定年代地层单位界线的方法。论证该段剖面沉积环境属泥质浅海陆棚。描述4个腕足动物新种。
In this paper, the Longmenshan Yanmen Dam Devonian section below the Central Plains junction zone divided into four brachiopod fossils. According to the principle of modern stratigraphy, the Lower Middle Line was determined at the top of the Ganxi Formation and marked by the first appearance of Xenospirifer fongi, which is equivalent to the international boundary layer. The paper proposes a method to determine the boundaries of the stratigraphic unit in an area without designated fossil zones. Demonstration section of the sedimentary environment is a shallow muddy shelf. Describe 4 new species of brachiopods.