五大连池第四纪火山岩层序划分及其构造与生态意义  

Sequences Division of Quaternary Volcanic Rocks in Wudalianchi and Its Tectonic and Ecological Significances

作　　者：曾普胜[1] 丘顺帆 李睿哲 刘斯文[1] 王十安 赵九江 ZENG Pu-sheng;QIU Shun-fan;LI Rui-zhe;LIU Si-wen;WANG Shi-an;ZHAO Jiu-jiang(Key Laboratory of Eco-geochemistry,Ministry of Natural Resources,National Research Center for Geoanalysis,Beijing 100037;Heilongjiang Institute of Geological Survey,Harbin,Heilongjiang 150036;China University of Geosciences(Beijing),Beijing 100083)

机构地区：[1]自然资源部生态地球化学重点实验室,国家地质实验测试中心,北京100037 [2]黑龙江省地质调查研究总院,黑龙江哈尔滨150036 [3]中国地质大学(北京),北京100083

出　　处：《地球学报》2021年第6期785-802,共18页Acta Geoscientica Sinica

基　　金：中国地质科学院基本科研业务费项目(编号:JYYWF20180101);中国地质调查局地质调查项目(编号:0100123057;DD20190589;DD20160220;DD20190703);国家自然科学基金项目(编号:41072073)联合资助。

摘　　要：大量前人成果和1:5万区调钻孔资料证实,五大连池第四纪火山地层属于水平岩层。因此,该地区第四纪火山地层的划分,是在地表岩石层序与钻孔岩石层序充分划分与对比的基础上进行的。从沉积角度看,五大连池火山地层属于松嫩盆地连续沉积过程中的第四纪短暂幕式火山喷发所形成的水平岩层。本文结合K-Ar同位素测年新资料,将该区第四纪岩石地层重新划分为11个组级地层单位。其中的火山岩石地层可以自下而上划分为:下更新统焦得布玄武岩(1.214-1.113 Ma);中更新统尾山玄武岩(0.62—0.285 Ma);中更新统笔架山玄武岩(0.24—0.132Ma)和全新统老黑山玄武岩(距今290~288a),对夹于其间的正常沉积地层也进行了相应的划分。对层状火山岩层序的层位划分和空间分布研究对于理解五大连池火山群的构造背景和生态环境具有特别重要的意义,五大连池火山群处于中国大陆内部的大同—大兴安岭火山岩带的最北东端,是地幔流体向北东方向流动的最前缘;这类富钾的碱性玄武岩的火山喷发活动对东北富饶的黑土地的形成具有重要贡献,火山岩在嫩江平原上塑造的台地和火山锥地形地貌对生态多样性和优质地下水的生态要素具有重要影响。A large number of data from predecessors and 1: 50 000 regional survey drilling confirm that the Quaternary volcanic strata in Wudalianchi belong to horizontal strata. Therefore, the division of quaternary volcanic strata in this area is based on the full division and correlation between surface and borehole sequences.From the sedimentary point of view, the Wudalianchi volcanic strata belong to the horizontal strata formed by the Quaternary episodic volcanic eruption in the continuous accumulating process of Song–Nen Basin. Based on the new data of K-Ar isotope dating, the Quaternary volcanic sequences in this area are divided into 11 formations,from bottom to top, corresponding fall into the Lower Pleistocene Jiaodebu basalt(1.214–1.113 Ma);Middle Pleistocene Weishan basalt(0.62–0.285 Ma);The Middle Pleistocene Bijiashan basalt(0.24–0.132 Ma) and the Holocene Laoheishan basalt(290–288 a BP) interlayered with two normal sedimentary strata. Study on volcanic rock sequences and spatial distribution of the stratovolcanoes is of great significances to understand the Wudalianchi volcanoes tectonic background and the ecological environment: Wudalianchi Volcano Group,located at most northeast end of the Datong–Daxinganling volcanic rock belt within the hinterland of NE China,is the most front of the mantle fluid flowing northeastward;The volcanic eruptions of these potassium-rich alkaline basalts contributed significantly to the formation of the rich black land in northeast China, and the platform and volcanic cone topography shaped by volcanic rocks on the Nenjiang Plain had an important impact on ecological diversity and the ecological elements of high-quality groundwater.

关 键 词：五大连池火山群 第四纪火山 火山岩层序 构造意义 生态意义 

分 类 号：P588.1[天文地球—岩石学] P535[天文地球—地质学]