Environmental change and process of mass extinction of Paleozoic oranisms in Yangtze Block during Late Paleozoic to Early Mesozoic time

扬子地块晚古生代至早中生代环境变化与古生代生物大灭绝过程

• 批准号: 03041069
• 负责人: YAO Akira
• 金额: $ 1.92万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03041069/
• 关键词: Yangtze Block; Permian-Triassic; Environmental change; Paleozoic organism; Mass extinction; Paleontology; Facies analysis

Environmental change and process of mass extinction of Paleozoic organisms in Yangtze Block during Late Paleozoec to Early Mesozoec timeThe main purpose of this project was to study the environmental changes and the processes of mass extinction of Paleozoic or, anisms at the end Permian. Emphasis was placed to clarify the vertical distributions of such mega- and microfossils as corals, radiolarians, conodonts and fusulinids through continuous straligraphc successions of the Permian to Triassic in the Yangize Block. In addition, we aimed to reconstruct the sedimentary environments across the Permian-Triassic boundary.The studied areas were west Guizhou and central to west Guangxi both on the Yangize Block. Following twelve sections (1-7 in Guizhou and 8-12 in Guangxi) were studied.1. Chouzushan (17km north of Anshun), G-H-I, 20m ; 2. Maoshachin (34km south of Ziyun), D-G-I, 400m ; 3. Saiwa (18km south of Ziyun), P3, 1100m ; 4. Taizucho (Guiyang), E-G-H-I, 240m ; 5. Duraying (Guiyang), C … More -E-G-I-J, 40m+ ; 6. Dwansha (85km south of Guiyang), D-G-I-K, 220m ; 7. Nashui (40km southwest of Luodian), D3-T1 ; 8. Tungtienyien (20km south of Liuzhou), A-B, 40m+ ; 9. Niumuping (10km northeast of Liuzhou), F-H, 200m+ ; 10. Linalang (20km east-northeast of Pingguo), D3-T1, 450m+ ; 11. Tsiping (20km northwest of Pingguo), A-C-F-K, 70m+ ; 12. Guofualungchiu (20km west of Pingguo), P-T1, 50m+(A) Chibsia Formation [P21] ; (B) Kufebg Fm. : (C) Maokou Fm. [P2, 2] ; (D) Wujiaping Fm. : (E) Lungtan Fm. : (F) Hoshan Fm. [P31] ; (G) Changxing Fm. : (H) Talung Fm. [P32] ; (I) Tayeh Fm. : (J) Yehlang Fm. : (K) Luolou Fm. [T11]In each section, litho- and biostratigraphic studies and systematic sampling of fossils and sedimentary rocks were carried out.1. LithofaciesThe Upper Permian is divided into three lithofacies ; carbonate, clastic and reworked-carbonate, and clastic and siliceous facies, which are equivalent to platform, slope and basin sediments, respectively. The uppermost Permian is conformably overlain by the Lower Triassic clastic rocks.2. Sedimentary faciesThe Lungtan Formation reveals coarsening-upward sequences of a deltaic origin as well as occasional occurrences of tidal flat deposits. The calcareous turbidite facies locally shows cyclic sedimentation demonstrated stacked thinning-upward sequences. Clastic facies of the Lower Triassic is interpreted as the shallow marine deposits as revealed by common presence of hummocky cross-stratification.3. BiofaciesRugose corals are common in the Middle Permian, but are sparse in the Upper Permian (Wujiaping and Changxin, Formations). Corals are facies-dependent and are variable in taxonomic composition from area to area. The uppermost Permian limestones occasionally contain abundant sponges and show bird's-eye structure. Radiolarians are abundant, especially in the Talung Formation of siliceous rocks. Less

在古生代晚期到早期的中元到早期的阳性块中古生代生物的质量扩展的环境变化和过程是该项目的主要目的是研究环境变化和古生代或质量在二叠纪的质量扩展的过程。重点是通过二叠纪的连续散曲率替代珊瑚，radialian骨，牙形特和熔融剂等珊瑚，radialian，肌肌肌动物和熔融剂等这种巨型化石和微化石的垂直分布的重点。此外，我们旨在重建跨二叠纪三叠纪边界上的沉积环境。研究二的地区是西吉州（Guizhou）和西广西（West Guangxi）的中心。在十二个部分（吉村为1-7，在广西地区为8-12）进行了研究。1。 Chouzushan（Anshun以北17公里），G-H-I，20m； 2。Maoshachin（Ziyun以南34公里），D-G-I，400m； 3。Saiwa（Ziyun以南18公里），P3，1100m; 4。Taizucho（Guiyang），E-G-H-I，240m； 5。 6。Dwansha（Guiyang以南85公里），D-G-I-K，220m； 7。Nashui（Luodian西南40公里），D3-T1； 8。Tungtienyien（Liuzhou以南20公里），A-B，40m+; 9。 10。Linalang（pingguo东北20公里），D3-T1，450m+; 11。 12。Guofalungchiu（pingguo以西20公里），P-T1，50m+（a）Chibsia组[P21]； （b）Kufebg FM。 ：（c）Maokou FM。 [P2，2]; （d）Wujiaping Fm。 ：（e）Lungtan FM。 ：（f）Hoshan FM。 [p31]; （g）Changxing FM。 ：（H）Talung FM。 [p32]; （i）Tayeh FM。 ：（J）Yehlang FM。 ：（k）Luolou FM。 [T11]在每个部分中，进行了岩性和生物术研究以及化石和沉积岩的系统采样。1。岩性上二叠纪被分为三个岩相；碳酸盐，经典和经典的碳酸盐以及经典和硅质的设施，分别等同于平台，坡度和盆地沉积物。最高的二叠纪被下层三叠纪经典岩石所覆盖。2。沉积物面部的隆坦形成揭示了三角洲起源和偶尔出现潮汐扁平沉积物的较粗糙的序列。钙质浊度面部局部显示循环沉积物表现出堆叠的稀疏序列。下三叠纪的碎屑设施被解释为浅层杂交跨分层的浅层海洋沉积物3。生物相质珊瑚在中二叠纪中很常见，但在上二叠纪（Wujiaping and changxin，地层）中稀疏。珊瑚是依赖相的相，并且在区域到区域的分类学组成中都是可变的。最高的二叠纪石灰岩偶尔包含丰富的海绵，并显示鸟类的眼睛结构。放射性人数丰富，尤其是在硅石岩石的形成中。较少的