“北祁连山蛇绿岩及其构造背景研究”专辑

北祁连中段早古生代双向俯冲—碰撞造山模式剖析

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  • 甘肃省地矿局研究所 兰州 730000;西安地质矿产研究所 西安 710054
左国朝,男,1937年3月出生,教授级高工,研究方向为区域地质、沉积地质及大地构造。

收稿日期: 1997-06-10

  网络出版日期: 1997-08-01

基金资助

本文为国家计委国地司科技找矿攻关项目“北祁连山西段镜铁山式铁铜金矿床成矿预测和定位研究”(1995~1997)的部分内容。

A BISUBDUCTION-COLLISION OROGENIC MODEL OF EARLY-PALEOZOIC IN THE MIDDLE PART OF NORTH QILIAN AREA

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  • Institute of Geoscience,Gansu Bureau of Geologyand Mineral Resources,Lanzhou 730000;Xi'an Institute of Geology and Mineral Resources,Xi'an 710054

Received date: 1997-06-10

  Online published: 1997-08-01

摘要

在十余年野外考察的基础上,通过火山—沉积组合、高压变质带及俯冲杂岩带产出特征、花岗岩浆活动、同位素年龄值等综合分析研究,结合近年区调成果,
提出北祁连中段地区早古生代的构造演化模式,认为该区是在古陆壳基底上由震旦纪打开经海底扩张生成的留有微陆块的微洋盆;寒武—奥陶纪,以黑河—八宝河为轴发生海底扩张,同时分别向南北两侧发生不对称双向俯冲,北侧以前进式的弧后扩张作用产生新生洋壳向北推进,相应早期的俯冲杂岩带也随之由南向北先后反弹回跳到地表,转化为汇聚过渡壳;南侧由早期被动陆缘的拉张过渡壳转为向南俯冲的阿拉斯加型活动大陆边缘,其后缘形成弧后盆地;志留纪俯冲作用停止,洋盆消失而转为岛链带及浊流海槽并存的构造格局;泥盆纪,北侧阿拉善地块与南侧中祁连地块最终汇聚而碰撞,形成以新陆壳为特征的造山带。

本文引用格式

左国朝,吴汉泉 . 北祁连中段早古生代双向俯冲—碰撞造山模式剖析[J]. 地球科学进展, 1997 , 12(4) : 315 -323 . DOI: 10.11867/j.issn.1001-8166.1997.04.0315

Abstract

A tectonic evolution model of Early Paleozoic in the middle part of North Qilian Area is put forward based on the field investigation of more than ten years, and a series of comprehensive researches, including volcanic sedimentary association, the characteristics of the complex in high pressure metamorphism zone, subduction complex rock zone, granitic magmatism and isotopic age, etc. In Sinian, paleocontinental crust broke up, and micro ocean basin was formed with remnant fragmants of continental crust. In Cambrian Ordovician, asymmetric bisubduction took place southward and northward respectively with Heihe Babaohe Zone being a spreading ridge. During the northward subduction, progressive back arc extension gave rise to a new ocean crust. This type of events took place northward repeatedly, and their correspondant products, subduction complexes, were elevated back to the surface and transformed into convergent transitional crusts. During the southward subduction, the earlier extentional transition crusts were transformed to Alaska type active continental margins which subducted southward, and subsequently arc back extensional basin was formed . In Silurian, with subduction ended and the oceanic basin disappearing, a tectonic framework with the coexistence of island chains and turbidity trough was formed. In Devonian, an orogenic belt with new continental crust was formed as the result of the convergence and collision between the Alaskan massif and the Middle Qilian massif.

参考文献

1 汤锡元,郭忠铭.鄂尔多斯地块西缘地质构造演化特征.见:鄂尔多斯盆地西缘掩冲带构造与油气.兰州:甘肃科学技术出版社,1990.77-90.
2 刘和甫,陆伟文,王玉新.鄂尔多斯西缘冲断褶皱带形成与形变.见:鄂尔多斯盆地西缘掩冲带构造与油气.兰州:甘肃科学技术出版社, 1990.54-75.
3 左国朝,王斌,吴汉泉,等.祁连地区蛇绿岩带划分及其构造意义.见:张旗主编.蛇绿岩与地球动力学研究.地质出版社,1996.129-134.
4 左国朝,刘寄陈.北祁连早古生代大地构造演化.地质科学, 1987, (1): 14-24.
5 许志琴,徐惠芬,张建新,等.北祁连走廊南山加里东俯冲杂岩增生地体及其动力学.地质学报,1994,68:1-14.
6 夏林圻,夏祖春,徐学义,等.北祁连山构造—火山岩浆演化动力学.西北地质科学, 1995, 16(1): 1-28.
7 王云山,李茂松,刘德权,等.青海省及毗邻地区变质地带与变质作用.北京:地质出版社, 1987.
8 Wu Hanquan, Tian Bai. New achievements on the study of the low-temperature metamorphism in North Qilian Mountains: discovery of lawsonite in southern high-grade blueschist belt and metamorphism of ophiolite in Yushigou, Qilian County, China, Very low grade metamorphism and geological applications: mechanisms and geological applications. Beijing: Seismological Press, 1994.156-167.
9 冯益民,何世平.祁连山大地构造与造山作用.北京:地质出版社, 1996.
10 Dick HJ B, Bullen T. Chromian spinel and alpine-type peridotites spatialy associated lavas. Contrib Mineral Petrol,1984, 86: 54-76.
11 陈雨,周进德,王二七,等.北祁连肃南县大岔大坂蛇绿岩中玻安岩石的发现及其地球化学特征.岩石学报,1995,11(增刊):147-153.
12 周德进,陈雨,张旗,等.北祁连南侧阿拉斯加型岩体的发现及地质意义.地质科学, 1997, 32: 122-127.
13 王廷印,刘金坤.青海省大坂山矿带火成岩地球化学特征及构造演化模式.兰州:兰州大学学报(自然科学版),1991, 27: 150-156.
14 刘训,韦光明,傅德荣,等.北祁连志留系复理石的再探讨.中国地质科学院院报, 1994, 29: 1-6.
15 王荃,刘雪亚.我国西部祁连山区的古海洋地壳及其大地构造意义.地质科学, 1976, (1): 42-55.
16 张新虎,苟国朝,田培昭,等.祁连山、北山地区古板块及地体构造的划分.西北地质, 1993, 14(2): 1-6.
17 肖序常,陈国铭,朱志直,等.祁连山古蛇绿岩的地质构造意义.地质学报, 1978, 52(1): 281-295.
18 何国琦,李茂松,刘德权,等.中国新疆古生代地壳演化及找矿.乌鲁木齐:新疆人民出版社, 1994.
19 Condie K C. Plate Tectonics and Crustal Evolution . 2nd Edition. New York: Pangamon, 1982.210-212.

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