鹿琪^1,2,3,,
张宫博¹,
刘财^1,2,4,,,
杨宝俊¹,
田有^1,2,3,
韩江涛^1,2,3
1. 吉林大学地球探测科学与技术学院, 长春 130026
2. 国土资源部应用地球物理重点实验室, 长春 130026
3. 油页岩地下原位转化与钻采技术国家地方联合工程实验室, 长春 130026
4. 吉林大学地质资源立体探测虚拟仿真实验教学示范中心, 长春 130026

基金项目: 国家自然科学基金（41430322，41574109）和国家重点研发计划项目（2016YFC0600505）共同资助


详细信息

作者简介: 鹿琪, 女, 1972年生, 教授, 主要从事探地雷达和地震数据处理、综合地球物理解释工作.E-mail:luqi@jlu.edu.cn

通讯作者: 刘财, 男, 1963年生, 教授, 主要从事地震波场正反演理论、综合地球物理研究工作.E-mail:liucai@jlu.edu.cn

中图分类号: P541;P631

收稿日期:2019-05-05
修回日期:2019-08-17
上线日期:2019-11-05

Crustal and upper mantle structure beneath the Da Hinggan Mountains region interpreted from geophysical profiles and its geological implications

LU Qi^1,2,3,,
ZHANG GongBo¹,
LIU Cai^1,2,4,,,
YANG BaoJun¹,
TIAN You^1,2,3,
HAN JiangTao^1,2,3
1. College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China
2. Key Laboratory of Applied Geophysics, Ministry of Land and Resources, Changchun 130026, China
3. National-Local Joint Engineering Laboratory of In-situ Conversion, Drilling and Exploration Technology for Oil Shale, Changchun 130026, China
4. Virtual Simulation Experiment Teaching Center of Stereoscopic Exploration of Geological Resource, Changchun 130026, China


More Information

Corresponding author: LIU Cai,E-mail:liucai@jlu.edu.cn

MSC: P541;P631

--> Received Date: 05 May 2019
Revised Date: 17 August 2019
Available Online: 05 November 2019


摘要
摘要:大兴安岭域，包括大兴安岭及其两侧盆地，穿过额尔古纳地块、兴安地块、松嫩地块和辽源地体.本文在东北地区已有的近东西向的全球地学断面（GGT）资料基础上，在大兴安岭两侧补充了2条近南北向的地球物理剖面，组构了综合地球物理栅状图；又结合区域内其他7条经综合解译的地球物理剖面，分析讨论了研究区壳幔结构特征及其地质意义.论文得到如下初步结果：（1）研究区莫霍界面以大兴安岭重力梯级带为分界，西部和东部深度有明显差异；以索伦山-西拉木伦河缝合带为界的南北岩石圈-软流圈界面（LAB）深度、软流圈有明显差异.呈现出地壳东西分带、岩石圈地幔南北分块的特征.（2）额尔古纳-兴安微板块具有较稳定的岩石圈地幔组构，与南部的中朝板块的岩石圈地幔具有较大差别；额尔古纳地块与西伯利亚板块的岩石圈特征更为接近.（3）获得古缝合带位置线索.林西以南的翁牛特下方存在明显的LAB南北向抬升，这是古亚洲洋闭合在岩石圈尺度上留下的遗迹；索伦山缝合带东延至西拉木伦河，是古亚洲洋闭合的场所.（4）大兴安岭域跨过两条板块缝合带，该区域北部与中部岩石圈组构特征相近，但它们的岩石圈地幔基底并不相同，这是在塔源-喜桂图缝合带于早古生代的拼合之后由数亿年的长期壳幔物质横向均衡作用所致.
关键词: 大兴安岭域/
壳幔结构/
地球物理剖面/
地球物理栅状图/
索伦山—西拉木伦河缝合带

Abstract:The Da Hinggan Mountains region includes the range itself and basins on its both sides, where three main microcontinents amalgamated named the Ergun block, Xing'an block, Songnen block, and Liaoyuan terrane. Based on three existing nearly EW-trending Global Geoscience Transects (GGT) and two NS geophysical profiles we acquired in the study region, a 2.5D geophysical fence diagram is established. Then combined with other seven reinterpreted geophysical profiles, the crust and upper mantle structure beneath this region is revealed and its geological implications are discussed. The results show that:(1) The depth of the Moho interface differs on the east and west sides of the Da Hinggan Mountains gravitational gradient belt. Similarly, the Lithosphere-Asthenosphere Boundary (LAB) depth and the features of asthenosphere differ in the north and the south of the Solonker-Xar Moron suture; (2) The Ergun-Xing'an block has a relatively stable lithospheric mantle structure, which is quite different from that of North China Craton, while similar to Siberian Craton; (3) There is a clear north-south striking uplift of LAB beneath Wengniute, south of Linxi, which marks the closure of the Paleo-Asian Ocean on the lithosphere scale. The Solonker suture zone extends eastward to the Xar Moron River where the Paleo-Asian ocean finally closed; (4) Two major plate sutures span across the Da Hinggan Mountains region, and the lithospheric structure is similar in its northern and central areas. But their lithospheric mantle basements are not the same, which was caused by a lateral isostasy of crust-mantle material for hundreds of millions of years after Tayuan-Xiguitu suturing in early Paleozoic.
Key words:Da Hinggan Mountains region/
Crust and upper mantle structure/
Geophysical profile/
Geophysical fence diagram/
Solonker-Xar Moron suture



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