Biostratigraphy of a Paleocene-Eocene Foreland Basin boundary in southern Tibet

来源 :Geoscience Frontiers | 被引量 : 0次 | 上传用户:yushu522216869
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
This study of the Paleocene—Eocene boundary within a foreland basin of southern Tibet, which was dominated by a carbonate ramp depositional environment,documents more complex environmental conditions than can be derived from studies of the deep oceanic environment.Extinction rates for larger foraminiferal species in the Zongpu-1 Section apply to up to 46%of the larger foraminiferal taxa. The extinction rate in southern Tibet is similar to rates elsewhere in the world,but it shows that the Paleocene fauna disappeared stepwise through the Late Paleocene,with Eocene taxa appearing abruptly above the boundary.A foraminifera turnover was identified between Members 3 and 4 of the Zongpu Formation—from the Miscellanea—Daviesina assemblage to an Orbitolites—Alveolina assemblage.The Paleocene and Eocene boundary is between the SBZ 4 and SBZ 5,where it is marked by the extinction of Miscellanea miscella and the first appearance of Alveolina ellipsodalis and a large number of Orbitolites. Chemostratigraphically,theδ~(13)C values from both the Zongpu-1 and Zongpu-2 Sections show three negative excursions in the transitional strata,one in Late Paleocene,one at the boundary,and one in the early Eocene.The second negative excursion ofδ~(13),which is located at the P—E boundary,coincides with larger foraminifera overturn.These faunal changes and the observedδ~(13)C negative excursions provide new evidence on environmental changes across the Paleocene—Eocene boundary in Tibet. This study of the Paleocene-Eocene boundary within a foreland basin of southern Tibet, which was dominated by a carbonate ramp depositional environment, documents more complex environmental conditions than can be derived from studies of the deep oceanic environment. Exposure rate for larger foraminiferal species in the Zongpu-1 Section apply to up to 46% of the larger foraminiferal taxa. The extinction rate in southern Tibet is similar to rates elsewhere in the world, but it shows that the Paleocene fauna disappeared stepwise through the Late Paleocene, with Eocene taxa appearing abruptly above the boundary. A foraminifera turnover was identified between Members 3 and 4 of the Zongpu Formation-from the Miscellanea-Daviesina assemblage to an Orbitolites-Alveolina assemblage. The Paleocene and Eocene boundary is between the SBZ 4 and SBZ 5, where it is marked by the extinction of Miscellanea miscella and the first appearance of Alveolina ellipsodalis and a large number of Orbitolites. Chemostratigraphically, the δ ~ (13) C values ​​from both the Zongpu-1 and Zongpu-2 Sections show three negative excursions in the transitional strata, one in Late Paleocene, one at the boundary, and one in the early Eocene. Second negative excursion of δ ~ (13), which is located at the P-E boundary, coincides with larger foraminifera overturn. These faunal changes and the observed δ ~ (13) C negative excursions provide new evidence on environmental changes across the Paleocene-Eocene boundary in Tibet.
其他文献
本文以人乳头状瘤病毒(HPV)16型-PBR_(322)重组质粒,对大肠杆菌HB101进行转化实验。经筛选、扩增、酶切、电泳鉴定。获得满意的电泳图谱及kb值,HPV-16Bam HI DNA为7.2kb,其26
【独门秘籍】期待你的来信:你正在为爱情烦恼?人际关系让你头痛不已?经常觉得没有朋友、无人理解?欢迎给我们来信,林小独将和你一起寻求答案。来信请发邮件至:dmmj@duzhe.cn
动脉瘤性蛛网膜下腔出血(aneurysmal subarachnoid hemorrhage,a SAH)是颅内出血的一个重要类型,占脑血管总发生率的12%~20%。随着血管内介入及外科手术治疗对蛛网膜下腔出血
大部分时尚杂志都希望自己的读者能像自己杂志里的女性一样,去买美丽的衣衫,昂贵的珠宝。当然,还有一个人纯粹是为了满足她的生活必需品才去订杂志!话说有一天,心情不错的X兔
抗体亲合力是抗体结合抗原的功能亲和力的一种量度。作者比较了用3种b型流感杆菌(Hib)结合菌苗预免疫后产生抗体的亲合力,并调查了亲合力与抗体激活补体介导杀菌的能力之间
中国科学院海洋研究所纪明候研究员的专著《海藻化学》一书,已由中国科学院科学出版基金资助,于1997年5月由科学出版社出版。这是一部集中外科学工作者研究海藻化学之大全的专
选题雷同是当今出版界令人忧虑的现象。选题雷同反映了一部分编辑专业水平的低下,犹如三流歌手,摹仿一流歌手的旋律,稍微改换几句歌词一样,永远成不了具有开创精神和创新能力的一
随着当前社会对人才的需求逐渐从专才向通才转变,通识教育教学作为一种人才培养模式,能改善过分专业化教育的弊病,培养学生博学多识,提高学生综合素质,适应社会发展的变化。
亲爱的木木:我和女友在一起一年。她对我不错,人也很好,有独立意识,有人生思考,相较其他女孩,给我不一样的感觉。问题是我们在两个相距遥远的城市。今年高考我考得不太理想,
CD_2(又称 LFA-2或 T-50)为单链跨膜糖蛋白,分子量50KD,含360个氨基酸(胞外区209个、跨膜区26个和胞内区125个),胞外区 N 末端24个氨基酸为信号肽.编吗 CD2的基因位于1号染