西南极乔治王岛新生代古生物特征及古环境探讨  

Cenozoic paleontological characteristics and paleoenvironment of King George Island,West Antarctica

作　　者：韦利杰[1,2,3] WEI Lijie(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Research Center of Polar Geosciences,China Geological Survey,Beijing 100081,China;Key Laboratory of Neotectonic Movement and Geohazard,Ministry of Natural Resources,Beijing 100081,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国地质调查局极地地学研究中心,北京100081 [3]自然资源部新构造运动与地质灾害重点实验室,北京100081

出　　处：《地质力学学报》2021年第5期855-866,共12页Journal of Geomechanics

基　　金：国家自然科学基金重点项目(41930218);中国地质调查局地质调查项目(DD20160060);中国-智利国际合作项目(中智合作南设得兰群岛1∶25万地质填图)。

摘　　要：西南极乔治王岛发育有一套高钾低铝的拉斑玄武岩,夹火山碎屑岩,属于岛弧火山岩系列。该岛还保存了南极最长的冰川沉积记录,是研究南极冰盖演化历史的重要证据。乔治王岛出露的新生代陆相地层中含有丰富的植物叶、孢粉、茎干、无脊椎动物化石及鸟类足印的痕迹化石等,从始新世到早中新世,化石逐渐减少,表明植物多样性呈明显下降趋势,幸存的稀疏植被被严格限制在冰川周缘的苔原物种上。冰海相地层与古生物研究表明,晚渐新世海相地层主要对应高能环境,早中新世海相地层对应低能环境。对乔治王岛新生代古生物特征及古环境的探讨,不仅理解了古生物及多样性的变化趋势,也为重建南极古环境提供证据。A set of high-K and low-Al tholeiites intercalated with volcanic clastic rocks developed in King George Island(Western Antarctica),belonging to the island arc volcanic rock series.Moreover,the longest record of glacial deposition in Antarctica is preserved on the island,which provides the important evidence of the Antarctic Ice Sheet evolution.Fossils of plant leaves,sporopollen,stems,invertebrate animals and bird footprints which were abundantly found in the outcropped Cenozoic continental strata of King George Island,started to decrease from the Eocene to the early Miocene,showing an obvious downward trend of plant diversity,and the surviving sparse vegetation was only the tundra species around the glacier.The studies of ice marine strata and paleontology suggest that the late Oligocene marine strata mainly correspond to high-energy environment and the early Miocene marine strata correspond to low energy environment.This paper explores the Cenozoic paleontological characteristics and paleoenvironment of King George Island,and the investigations allow us to understand the trend of paleontological diversity and provide evidence for the reconstruction of the Antarctic paleoenvironment as well.

关 键 词：西南极 新生代 乔治王岛 古生物 古环境 

分 类 号：Q91[天文地球—古生物学与地层学] P532[生物学—古生物学]