岷江叠溪古堰塞湖沉积物中孢粉特征  

The Pollen and Spore Characteristics of the Diexi Ancient Dammed Lake on the Upstream of Minjiang River

作　　者：王小群[1] 王兰生[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《地球科学（中国地质大学学报）》2013年第5期975-982,共8页Earth Science-Journal of China University of Geosciences

基　　金：中国国家自然科学基金(No.41072230);地质灾害防治与地质环境保护国家重点实验室自主课题(No.SKLGP2012Z008)

摘　　要：对岷江上游叠溪古堰塞湖200余米厚的堰塞湖相沉积物进行了大量采样测试分析.主要对湖相沉积物中的孢粉和沉积年代进行了测试.通过测试获得了古堰塞湖沉积物的沉积时间和气候环境特征.古堰塞湖沉积物底部形成时间约3.0万年,靠近顶部形成时间约为1.5万年前.孢粉测试结果显示,古堰塞湖沉积物沉积剖面可划分为9个气候环境段：（1）温凉半湿润的针阔叶混交森林草原气候环境;（2）寒冷干旱的针叶森林草原气候环境;（3）温凉半干旱的针、阔叶混交疏林草原气候环境;（4）温暖湿润的针、阔叶混交森林草原气候环境;（5）凉半干的针、阔叶混交疏林草原气候环境;（6）温湿的针叶疏林草原气候环境;（7）温凉半干旱的针阔叶混交疏林草原气候环境;（8）凉半湿润的森林草原气候环境;（9）冷干的疏林草原气候环境.研究成果揭示了青藏高原东部边缘至四川盆地过渡带3.0~1.5万年间的古气候古环境演化特征,为区域环境研究提供了宝贵的资料.Many samplings,tests and analysis are carried out to study the lacustrine sediments which are more than 200mthick inside the Diexi ancient dammed lake on Minjing river.The pollen and spore of the sediments and sedimentation time are tested by which the ancient dammed lake sedimentation time and climate-environment characteristics are obtained.It is found that bottom parts of the ancient dammed lake lacustrine sediments were formed 30 000years ago,while the parts close to the top formed 15 000years ago.The pollen and spore test results indicate that the sediment section of the ancient dammed lake can be classified into the following 9climate-environment sections：（1）Cool and semi-moist,needle leave and broad leave mixed forest and grassland climate-environment;（2）cold and dry,needle leave forest and grass land climate-environment;（3）cool and semi-moist,needle leave and broad leave mixed open forest and grassland climate-environment;（4）warm and humid,needle leave and broad leave mixed forest grassland climate-environment;（5）cool and semi-dry,needle leave and broad leave mixed open forest and grassland climate-environment;（6）cool and semi-moist forest and grassland climate-environment;（7）cold and dry,open forest and grassland climate-environment.The evolution characteristics of the Palaeo-climate and Palaeoenvironment of the transition area of east edge of Qinghai-Tibetan Plateau to Sichuan basin during time period between 30 000 to 15 000years ago is described,which can provide information for the regional environment study.

关 键 词：岷江 叠溪 古堰塞湖 沉积物 孢粉 气候变化 古气候环境 

分 类 号：P642[天文地球—工程地质学] X141[天文地球—地质矿产勘探]