东亚三叠纪古生物地理

TRIASSIC PALEOBIOGEOGRAPHY OF EASTERN ASIA

在早、中三叠世,东亚古生物地理分区可分为属北温带的劳亚北部大区、属北暖温带的劳亚中部大区、属热—亚热带的华夏特提斯区、属南温带的冈瓦纳大陆区及冈瓦纳特提斯区。该分区状态在晚三叠世发生了重大变化。冈瓦纳大陆区以外的东亚地区形成了环太平洋大区、特提斯大区(热—亚热带)、劳亚大陆大区(温—暖温带)三足鼎立的局面。分区是温度—纬度阻隔和板块—洋陆阻隔双重控制的结果。在反映板块构造方面,东亚地区三叠纪的古生物地理分区表明,此时雅鲁藏布江一线存在着中特提斯洋的阻隔,100°E以东的东亚范围内已无大洋阻隔,而晚三叠世时太平洋构造域已明确形成。

The Early and Middle Triassic paleobiogeographic provincialization of Eastern Asia consists of the northern temperate North Laurasia Realm, the northern warm-temperate Central Laurasia Realm, the tropical-subtropical Cathaysian Tethys Region, the southern temperate Gondwana Continental Region and Gondwanan Tethys Region. Remarkable changes took place in Late Triassic. Eastern Asia north of the Gondwana Continental Region displayed a tripartition consisting of the Circum-Pacific Realm, the tropical-subtropical Tethys Realm and the temperate to warm -temperate Laurasia Realm. The provincializaton is controlled both by temperature-latitude separation and plate-ocean and continent separation. As to its significance in plate tectonics, the provincialization demonstrates that during Triassic the Mesogea or Mesotethys Ocean existed along Yarlung Zangbo line, that east of 100° E in eastern Asia there was no vast oceanic separation, although small ocean basins might exist in areas between Yarlung Zangbo and Kunlun -Qinling. It also denotes that the Paleopacific tectonic realm formed in Late Triassic.