西藏亚东堆纳地区古近纪介形虫生物地层
发布时间：2018-12-18 06:13
【摘要】：被誉为“世界屋脊”的青藏高原地处亚洲大陆的南部,由于其独特的自然环境和复杂的地壳结构,长期以来一直为广大地学工作者所关注。它是印度板块向欧亚板块俯冲碰撞的结果,而碰撞过程是连续的,无法留下明显可见的地质记录,因此需要利用碰撞事件发生前后产生的地质记录来确定事件发生的上限时间和下限时间,后逐渐缩小上限和下限的间隔,从而预测碰撞事件的时代。本文主要是运用微体古生物地层学的研究方法来确定西藏特提斯最终闭合的时间,从而为印度—亚欧板块碰撞拼合的时间上限提供约束条件。本次研究的剖面—古鲁浦剖面位于西藏南部亚东堆纳地区,在沉积—构造分区上位于特提斯喜马拉雅带的南亚带。该区域海相古近系发育较好,且古生物化石种类多,含丰富的浮游有孔虫、底栖有孔虫、介形虫、藻类等。本文主要对该剖面的介形虫生物群进行研究。通过对西藏亚东堆纳古鲁浦剖面遮普惹组砂页岩段的介形虫化石进行鉴定及分析,共鉴定出介形虫化石18属36种,划分出3个介形虫化石组合,自老至新分别是:Alocopocythere curvata-Cytherella compressa组合,Bairdia fabaeformis-Monsmirabilia subovata组合,Bairdia dignata-Bairdia lauta组合。通过对划分出来的这3个介形虫化石组合特征的分析,并结合与其共同产出的有孔虫化石组合的时代特征,确定亚东堆纳古鲁浦剖面遮普惹组砂页岩段的时代为Priabonian早期以后。
[Abstract]:The Qinghai-Xizang Plateau, known as the "roof of the world", is located in the southern part of the Asian continent. Due to its unique natural environment and complex crustal structure, it has long been the focus of geoscientists. It is the result of a subduction of the Indian plate to the Eurasian plate, and the collision process is continuous and cannot leave a visible geological record. Therefore, it is necessary to use the geological records before and after the collision event to determine the upper and lower limit time of the event, then gradually reduce the interval between the upper and lower bound, so as to predict the time of collision event. In this paper, the method of micropaleostratigraphy is used to determine the time of final closure in Tethys, Tibet, thus providing a constraint for the upper limit of the time limit for the collision of the Indo-Eurasian plate. The profile-Gulupu section in this study is located in the Yadong Dina area in southern Tibet and in the south Asia belt of the Tethys Himalayan belt on the sedimental-tectonic zoning. The marine Paleogene is well developed, and there are a lot of paleontological fossils, including planktonic foraminifera, benthic foraminifera, ostracoda, algae and so on. In this paper, the ostracod biota of this section is studied. Based on the identification and analysis of ostracoda fossils in the sand shale section of the Zapuja formation in the Nagurupu section of Yadong, Tibet, a total of 18 genera and 36 species of ostracoda fossils were identified and divided into 3 assemblages of ostracoda fossils. From old to new are: Alocopocythere curvata-Cytherella compressa combination, Bairdia fabaeformis-Monsmirabilia subovata combination, Bairdia dignata-Bairdia lauta combination. Based on the analysis of the characteristics of the three ostracod fossil assemblages and the age characteristics of the foraminiferal assemblages, it is concluded that the age of the sand shale of the Zapuja formation in the Nagurupu section of the Yadong DUI is after the early Priabonian.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q915;P534.6
本文编号：2385480
[Abstract]:The Qinghai-Xizang Plateau, known as the "roof of the world", is located in the southern part of the Asian continent. Due to its unique natural environment and complex crustal structure, it has long been the focus of geoscientists. It is the result of a subduction of the Indian plate to the Eurasian plate, and the collision process is continuous and cannot leave a visible geological record. Therefore, it is necessary to use the geological records before and after the collision event to determine the upper and lower limit time of the event, then gradually reduce the interval between the upper and lower bound, so as to predict the time of collision event. In this paper, the method of micropaleostratigraphy is used to determine the time of final closure in Tethys, Tibet, thus providing a constraint for the upper limit of the time limit for the collision of the Indo-Eurasian plate. The profile-Gulupu section in this study is located in the Yadong Dina area in southern Tibet and in the south Asia belt of the Tethys Himalayan belt on the sedimental-tectonic zoning. The marine Paleogene is well developed, and there are a lot of paleontological fossils, including planktonic foraminifera, benthic foraminifera, ostracoda, algae and so on. In this paper, the ostracod biota of this section is studied. Based on the identification and analysis of ostracoda fossils in the sand shale section of the Zapuja formation in the Nagurupu section of Yadong, Tibet, a total of 18 genera and 36 species of ostracoda fossils were identified and divided into 3 assemblages of ostracoda fossils. From old to new are: Alocopocythere curvata-Cytherella compressa combination, Bairdia fabaeformis-Monsmirabilia subovata combination, Bairdia dignata-Bairdia lauta combination. Based on the analysis of the characteristics of the three ostracod fossil assemblages and the age characteristics of the foraminiferal assemblages, it is concluded that the age of the sand shale of the Zapuja formation in the Nagurupu section of the Yadong DUI is after the early Priabonian.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q915;P534.6
【参考文献】
相关期刊论文 前1条
1 李国彪,万晓樵,刘文灿,梁定益,H.Yun;雅鲁藏布江缝合带南侧古近纪海相地层的发现及其构造意义[J];中国科学(D辑:地球科学);2004年03期
，本文编号：2385480
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