新生代特提斯海峡关闭过程及其圈层耦合效应  

Stepwise closure of the Tethyan Seaway and its impact on the Earth’s multi-sphere interactions during the Cenozoic

作　　者：孙继敏[1,2] 沙金庚 王世骐[4] Jimin Sun;Jingeng Sha;Shiqi Wang(Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences,Nanjing 210008,China;Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044,China)

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中国科学院大学地球与行星科学学院,北京100049 [3]中国科学院南京地质与古生物研究所,南京210008 [4]中国科学院古脊椎动物与古人类研究所,北京100044

出　　处：《科学通报》2024年第2期184-199,共16页Chinese Science Bulletin

基　　金：国家自然科学基金(41888101);中国科学院战略性先导科技专项(XDA20070202);中国地质调查局项目(DD20221829)资助。

摘　　要：新生代是地球历史上岩石圈、水圈、大气圈、生物圈发生宏观巨变的重要地质时期,包括了冈瓦纳大陆的快速裂解、海峡的开启与闭合、海洋与大气环流的重组、温室到冰室的气候转型以及动植物的快速演替,因而是开展圈层耦合研究的关键地质时期.本文以特提斯海峡为例,从地球系统科学角度,阐述特提斯海峡的闭合过程、时间及其对生物圈、海洋环流、大气圈的链式影响和反馈.核心思想如下:特提斯海峡自渐新世至中-中新世晚期(34∼12.8 Ma)历经了阶段性的演化过程,渐新世时期的特提斯海峡很好地连通了低纬度的印度洋-古地中海-大西洋;早中新世时(21∼19 Ma),伴随着非洲-阿拉伯板块与欧亚大陆的汇聚,海峡的连通能力下降了90%;中-中新世气候适宜期(17∼15 Ma)以海岸潟湖相为主、夹浅海相环境;15∼12.8 Ma期间演化为陆相环境为主、夹短暂的周期性海侵,且具有10万年的准周期;12.8 Ma之后,海峡永久关闭.特提斯海峡的闭合过程对生物圈产生了显著影响,伴随海峡的逐渐闭合,海洋无脊椎动物的腹足类、棘皮类,逐渐从特提斯海向印度洋、西太平洋迁移.对哺乳动物而言,尽管早中新世已经有零星的哺乳动物在非洲-阿拉伯与欧亚大陆之间迁徙,但真正大规模的哺乳动物双向迁徙主要发生在18∼17 Ma之后.此时,以海岸潟湖相为主的海峡已不足以构成善于利用迁徙路径的哺乳动物的地理屏障,表现为非洲的灵长类、长鼻类、蹄兔类等向欧亚大陆迁徙.而欧亚大陆的食肉类、犀类、猪类、反刍类、啮齿类等向非洲-阿拉伯迁徙.特提斯海峡的关闭对海洋环流也有重要影响,主要表现为特提斯海峡的关闭减少了来自低纬的温暖、高盐海水向大西洋及印度洋南部的注入,由此降低了低纬的热量向南半球高纬的径向输送,在一定程度上加强了东南极冰盖的扩张及南极的变冷.�The Cenozoic era is an important period marked by significant changes in various Earth’s spheres(lithosphere,hydrosphere,atmosphere,and biosphere),which include the break-up of the Gondwana Supercontinent,the opening and closure of oceanic straits,the reorganization of atmospheric circulation,the climate transition from greenhouse to icehouse,and the rapid evolution of animals and plants.Therefore,it is a key geological period for studying the coupling between the different Earth’s spheres.This review takes the Tethyan Seaway as an example to explain the timing and process of the closure of the Tethyan Seaway and its main impact and feedback on the biosphere,ocean circulation,and atmosphere from the perspective of Earth System Science.Based on multidisciplinary research into different tectonic domains of the Iranian Plateau,we reveal that the closure of the Tethyan Seaway,which separates the Arabian and Eurasian Plates,has undergone a stepwise evolution.From the Oligocene to the early Miocene(34–19 Ma),the Tethyan Seaway was well connected with the Indian Ocean,the proto-Mediterranean,and the Atlantic,indicated by the mutual high commonality of marine gastropods between them.During the late early Miocene(19–17 Ma),when the Tethyan Strait was partially open,both the Nd isotopes of seawater and the commonality of marine gastropods demonstrate that the passage capacity of seawater decreased by 90%.During the Mid-Miocene Climate Optimum(MMCO)(17–15 Ma),despite rising sea levels caused by global marine transgression,the increased temperature during the MMCO enhanced seawater evaporation,resulting in an environment dominated by coastal lagoons and only occasionally replaced by shallow seas.During the Middle Miocene Climatic Transition(MMCT)(15–12.8 Ma),the Tethyan Seaway evolved into a continental environment but interrupted by short-term periodic marine transgressions,which had a quasi-period of 100-ka between 15 and 12.8 Ma.Such a cycle is likely to be related to periodic ice sheet expansion/melting and t

关 键 词：阿拉伯与欧亚大陆汇聚 特提斯海峡闭合 海陆分布 地球圈层相互作用 环境效应 

分 类 号：P534.6[天文地球—古生物学与地层学]