摘要
亚洲渐新世不是原认为的三分,而是仅包括两个期:早渐新世三达河期和晚渐新世塔奔布鲁克期。我国渐新世的地方动物群排序为:早渐新世包括(从早到晚)克克阿木、乌兰布拉格早期和乌兰布拉格晚期3个动物群;晚渐新世包括(从早到晚)4个动物群:沙嘎特动物群、塔奔布鲁克动物群、伊克布拉格动物群和索索泉动物群。“始新世末事件”在亚洲也很明显,主要表现为较原始的古老的哺乳动物在渐新世初就大量迅速绝灭。在渐新世期间,哺乳动物的变化主要表现为进化程度上的演变和替代。上述演变主要与当时全球的气候变冷、变干燥和亚洲地形的变化有关。
The Jurassic is well developed and trends in NE direction in Dujiangyan, Pengzhou and Shifang of the middle segment of Longmen Mountains, Sichuan. Some Jurassic sections were surveyed in the regions during the 1∶50000 regional geological survey from 1991 to 1995. From these sections, four lithostratigraphic units, namely Qianfuya Formation, Shaximiao Formation, Suining Formationand Lianhuakou Formation were recognized and correlated with the corresponding units in the adjacent areas. Their lithologic characters and facies change were summarized. The Jurassic chronostratigraphy is discussed on the basis of ESR dating data. The bases for the division of the lake facies of Qianfuya period, the allurial facies of Shaximiao-Suining period and the pluvial facies of Lianhuakou period are briefly described.
出处
《地层学杂志》
CSCD
北大核心
1997年第3期183-191,共9页
Journal of Stratigraphy
基金
国家自然科学基金
中国科学院古生物与古人类学科基础研究资助
关键词
中国
陆相
渐新世
哺乳动物群
古动物
地层
Sichuan, Dujiangyan, Pengzhou, Shifang, Jurassic, stratigraphical correlation, chronostratigraphy