羌中变质带的早二叠和二叠纪-三叠纪界限牙形石数据

位于藏北的塘中变质带（CQMB），全长超过500公里，为研究羌塘块体的构造演化和古生物地理提供了宝贵的材料。作者首次报告了来自CQMB角木日地区的两套牙形石化石（the Mesogondolella and Clarkina–Hindeodus–Isarcicella faunas）。在角木茶卡2（N: 33.14°, E: 87.03°）和江爱藏布剖面（N: 33.22°, E: 86.88°）发现了Mesogondolella fauna，包括M. siciliensis、M. qiangtangensis和?M. sp.，表明其年龄为晚空谷期（早二叠世）。在角木茶卡1剖面（N: 33.18°, E: 87.04°）上，确定了来自Clarkina–Hindeodus–Isarcicella的20个牙形石种类，隶属于5个属，并在该化石群中建立了两个牙形石生物带。此外，还在该剖面识别出Borinella nepalensis。根据牙形石的序列，暂时将二叠纪—三叠纪边界（PTB）界定在Clarkina yini和Isarcicella staeschei生物带之间。晚空古期Mesogondolella生物群属于温水和冷水牙形石之间的过渡带，与南羌塘地体（SQT）西南部的牙形石群落稍有不同。CQMB和SQT南部未发现与之同时期的冷水牙形石如Vjalovognathus和M. idahoensis，表明它们与拉萨块体、东缅甸和西澳之间的古生物地理关系较弱。在PTB界限的Clarkina–Hindeodus–Isarcicella牙形石生物群中，地方性物种C. sosioensis与温水Iranognathus的共存，可能表明SQT已漂移至赤道地区，并与伊朗之间具有紧密关系。

The Central Qiangtang Metamorphic Belt (CQMB) in northern Tibet, with a total length of over 500 km, provides valuable materials for studying the tectonic evolution and paleobiogeography of the Qiangtang Block. The authors report for the first time two sets of conodont fossils from the Jiaomuri area of CQMB: the *Mesogondolella* and *Clarkina–Hindeodus–Isarcicella* faunas. The *Mesogondolella* fauna was discovered at the Jiaomuchaka 2 (N: 33.14°, E: 87.03°) and Jiang'aisangbu sections (N: 33.22°, E: 86.88°), including *M. siciliensis*, *M. qiangtangensis*, and ?*M. sp.*, indicating an age of the Late Kungurian (Early Permian). At the Jiaomuchaka 1 section (N: 33.18°, E: 87.04°), 20 conodont species belonging to 5 genera of the *Clarkina–Hindeodus–Isarcicella* fauna were identified, and two conodont biozones were established within this fossil assemblage. Additionally, *Borinella nepalensis* was identified at this section. Based on the conodont succession, the Permian-Triassic Boundary (PTB) was tentatively defined between the *Clarkina yini* and *Isarcicella staeschei* biozones. The Late Kungurian *Mesogondolella* fauna belongs to a transitional zone between warm-water and cold-water conodonts, and differs slightly from the conodont communities in the southwestern part of the South Qiangtang Terrane (SQT). No contemporaneous cold-water conodonts such as *Vjalovognathus* and *M. idahoensis* have been found in the southern parts of CQMB and SQT, indicating weak paleobiogeographic affinities between these areas and the Lhasa Block, eastern Myanmar, and Western Australia. In the *Clarkina–Hindeodus–Isarcicella* conodont fauna associated with the PTB boundary, the co-occurrence of the endemic species *C. sosioensis* and the warm-water *Iranognathus* may indicate that the SQT had drifted to the equatorial region and had close affinities with Iran.

搜集汇总

背景与挑战

背景概述

该数据集提供了藏北羌中变质带（CQMB）的早二叠世和二叠纪-三叠纪界限牙形石化石数据，包括Mesogondolella和Clarkina–Hindeodus–Isarcicella两个动物群，用于研究古生物地理和古气候。数据涵盖角木茶卡和江爱藏布剖面，识别出多个牙形石种类并建立生物带，有助于界定二叠纪-三叠纪边界，并揭示了该地区与温水过渡带及伊朗的古生物地理联系。