演化中的裂谷带——五大连池火山岩带  

The evolving rift belt—Wudalianchi volcanic rock belt.

作　　者：邵济安[1,2] 张文兰[3] 

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室,北京100871 [2]中国科学院地质与地球物理研究所,中国科学院矿产资源研究重点实验室,北京100029 [3]南京大学地球科学系,江苏南京210093

出　　处：《地学前缘》2008年第6期241-250,共10页Earth Science Frontiers

基　　金：国家自然科学基金项目(40672039;90714008);中国科学院矿产资源研究重点实验室资助项目

摘　　要：小古里河—科洛—五大连池—二克山新生代火山岩带是一条富钾火山岩带。文中重点论述了以下4点内容:(1)火山岩及其包体中存在典型的地幔交代作用;(2)根据火山岩K2O/Na2O比值勾画出富钾火山岩带范围;(3)地幔气体的绝热膨胀导致"冷泉和冻土现象";(4)地震活动的现状。论证了NNW走向的五大连池火山岩带是新生代初始的大陆裂谷,它们切穿了大兴安岭北北东向构造带。进一步从岩浆演化的趋势认为五大连池裂谷带将持续演化而不会夭折。The Xiaogulihe-Keluo-Wudalianchi-Erkeshan Cenozoic volcanic rock belt is one rich in potassium.Four facts about this belt are analyzed in this work：（1）typical mantle metasomatism existing in the volcanic rocks and in their inclusions,（2）the distribution range of the K-rich volcanic belt estimated according to the K2O/Na2O ratio of the volcanic rocks,（3）the ＂cold spring and taele phenomenon＂ caused by adiabatic expansion of the mantle gases,and（4）the current situation of seismic activities.It is inferred from those facts that the NNW-strike Wudalianchi volcanic rock belt is a Cenozoic primal continental rift cutting through the NNE-strike Da-Hinggan-Mt.tectonic belt.The evolution tendency of its magma suggests that the Wudalianchi rift belt is still in a course of continuing evolution without a sign of coming to an end.

关 键 词：新生代 富钾火山岩带 大陆裂谷 地震活动 岩浆演化 

分 类 号：P54[天文地球—构造地质学]