PALEONTOLOGICAL AND PETROLOGICAL STUDY OF LIMESTONES IN THE PERMIAN-TRIASSIC BOUNDARY

一次钻探(深度50米。(直径70毫米)，目的是获得在Tahokamigumi露出的Taho石灰岩中二叠系-三叠系界线的信息。白川町。东秀和君。爱美县。通过钻探岩心的研究，发现了下三叠统格里斯巴克期牙形刺Hindeodus minutus。微小隐翅虫H.parvus。然后呢？Isarcicella isarcica产于22.80~23.45m的深灰色白云质石灰岩和二叠纪的丝虫Staffella sp.从宏伟地表以下23.50米处的浅灰色白云质石灰岩中分离出来。三叠系石灰岩为塔霍组，二叠系石灰岩为白川组。上二叠统三台组与三叠系镰村组之间的界线暴露在西野沟。高知浩。西须君。宫崎县。我们确认了微小隐球线虫的存在。微小隐翅虫H.parvus。Isarcicella is…更多的是极品。和来自镰村组底部3m的深灰色石灰岩中的小腹足类Neogondolella carinata。二叠系三台组恰好位于镰村组之下。米台组的最上部通常是强烈的白云石化和不含化石的，但二叠纪的丝状虫Staffella sp.赋存于边界附近有孔虫和钙藻的弱白云石化灰岩中。如上所述，我们可以确认白川组和镰村组中存在格里斯巴克氏生物。这是首次确认侏罗纪扬子大陆上沉积的海底火山岛上沉积的格里斯巴赫生物。有趣的是，格里斯巴奇统灰岩和上二叠统灰岩在两个剖面上表现出非常相似的岩相。Taho和Shioinousou。格里斯巴克期的深灰色泥晶灰岩沉积于低能缺氧环境，而上二叠统(长兴统)浅灰色泥晶灰岩沉积于低能缺氧环境。白云石化作用发生在晚二叠世至早三叠世。较少

A drilling (50 m in depth. 70 mm in diameter) was performed in 1994 for the purpose of getting information about the Permian-Triassic boundary in the Taho Limestone exposed in Tahokamigumi. Shirokawa-cho. Higashiuwa-gun. Ehime Prefecture. As a result of investigation of the drilling core, there occures the lower Triassic Griesbachian conodont Hindeodus minutus. H.parvus. and? Isarcicella isarcica from the dark gray dolomitic limestone in the level of 22.80 m to 23.45 m and permian fusulinid Staffella sp. from the light gray dolomitic limestone at the level of 23.50 m below the grand surface. We propose the Taho Formation for the Triassic limestone and the Shirokawa Formation for the Permian Limestone. The boundary between the formations is conformable.The boundary between the Upper Permian Mitai Formation and the Triassic Kamura Formation exposed in Shioinosou. Takachiho-cho. Nishiusuki-gun. Miyazaki Prefecture. We confirmed the occurrence of Hindeodus minutus. H.parvus. Isarcicella is … More arcica. and Neogondolella carinata from the dark gray limestone with small gastropods in the basal 3 m of the Kamura Formation. The Permian Mitai Formation conformably underlies the Kamura Formation. The uppermost part of the Mitai Formation is usually strongly dolomitized and unfossiliferous but Permian fusulinid Staffella sp. occurs in the weakly dolomitized limestone with foraminifers and calcareous algae near the boundary.As mentioned above we could confirm the Griesbachian in the Shirokawa and the Kamura Formation. This is the first confirmation of the Griesbachian deposited on the submarine volcanic island which accreted to the Yangtze continent in Jurassic. It is quite interesting that the Griesbachian limestone and Upper Permian limestone represent close similarity in lithofacies between two sections. Taho and shioinousou. The dark gray micritic limestone of the Griesbachian deposited in low energy and anoxic environment and light gray micritic limestone of the Upper Permian (Changxingian) sedimented in low energy and oxic environment. The dolomitization occured during the Late Permian and Early Triassic. Less