北祁连—河西走廊志留纪和泥盆纪古地理及其对同造山过程的沉积响应  

SILURIAN AND DEVONIAN PALAEOGEOGRAPHY OF NORTHERN QILIAN-HEXI CORRIDOR AND ITS SEDIMENTARY RESPONSE TO SYNORNGENESIS OF NORTH QILIAN OROGENIC BELT

作　　者：杜远生[1] 张哲[1] 周道华[1] 彭冰霞[1] 

机构地区：[1]中国地质大学(武汉),湖北武汉430074

出　　处：《古地理学报》2002年第4期1-8,共8页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目 (4 9972 0 78)资助

摘　　要：北祁连—河西走廊志留系包括下志留统鹿角沟砾岩和肮脏沟组、中志留统泉脑沟山组和上志留统旱峡组 ,泥盆系包括中、下泥盆统老君山组和上泥盆统沙流水组。鹿角沟砾岩为水下冲积扇沉积 ,断续分布于北祁连西段。肮脏沟组在北祁连—河西走廊分布广泛 ,主要为半深海碎屑复理石沉积。泉脑沟山组和旱峡组分布于北祁连—河西走廊西段 ,前者以浅海相砂泥岩和泥灰岩为主 ,后者以滨海潮坪—浅海碎屑岩沉积为主。老君山组分布于古祁连山山前和山间盆地 ,为粗碎屑磨拉石沉积。沙流水组分布于河西走廊东段 ,为湖相沉积。区域古地理分析表明 ,北祁连—河西走廊志留纪和泥盆纪的古地理主要受北祁连加里东—早海西期不规则造山作用控制。鹿角沟砾岩标志着弧—陆碰撞最早发生于早志留世早期。早志留世北祁连—河西走廊由弧后残余盆地向前陆盆地转化。中、晚志留世北祁连东段剧烈造山并与阿拉善古陆连接 ,前陆盆地限于北祁连—河西走廊西段。志留纪末期为北祁连的主造山期 ,泥盆纪形成高峻的古祁连山。早、中泥盆世形成山前和山间盆地的粗碎屑磨拉石沉积。晚泥盆世造山带西段造山作用剧烈 ,形成剥蚀区。东段造山作用微弱 ,山地被剥蚀 。Silurian of Northern Qilian-Hexi Corridor consists of the Early Silurian Lujiaogou Conglomerate and Angzanggou Formation,the middle Silurian Quannaogoushan Formatoin and the Late Silurian Hanxia Formation.Devonian consists of the Early and middle Devonian Laojunshan formationand the Late Devonian Shaliushui Formation.The Lujiaogou Conglomerate is intermittently distributed over the western section of the Northern Qilian Mountains and is the deposits of submarine alluvial fan.The Angzanggou Formation is widely distributed over the Northern Qilian-Hexi Corridor and is mainly bathyal flysch deposits.The Quannaogoushan Formation and Hanxia Formation are distributed in the western regions of Northern Qilian-Hexi Corridor.The Quannaogoushan Formation is composed of the neritic deposits of sandstone,mudstone and marlite,and the Hanxia Formation of the littoral and neritic sandstone and mudstone.The Laojunshan Formation is dispersed over the piedmont and intermountainous basin of Paleo Qilian and is composed of coarse clastic molasse.The Shaliushui Formation is distributed over the eastern region of the Hexi Corridor and is composed of sandstone and mudstone of lacustrine facies.The Silurian and Devonian regional palaeogeography is controlled by the irregular orogenic process of the Northen Qilian from the Caledonian to Early Hercynian.The Lujiaogou Conglomerate is the sedimentary response to arc continental collision during the earliest of Silurian.In the Early Silurian,the Northern Qilian Hexi Corridor transforms from back arc survival basin to foreland basin.In the Middle and Late Silurian,the orogeny in the eastern part of North Qilian is strong.Connection between the eastern part of the orogenic belt and Alashan paleo continental formed a disintegration area.The foreland basin is merely located in the western region of North Qilian and Hexi Corridor.The latest Silurian is main orogenic stage of North Qilian.The Devonian Qilian is high and the Early and Middle Devonian molasse formed in the piedmont and intermou

关 键 词：祁连山 泥盆纪 志留纪 古地理 同造山过程 沉积响应 造山作用 

分 类 号：P534.43[天文地球—古生物学与地层学] P534[天文地球—地质学]