【作者】 许立权；

【导师】 邓晋福；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2005， 博士

【摘要】 内蒙古白云鄂博-满都拉地区跨越了华北地台和兴蒙造山带两大构造单元。它的一个显著特点是广泛发育古生代-中生代岩浆岩。论文以近几年在白云鄂博和满都拉地区开展的1/25 万区调为基础,详细的论述了区内加里东期、华力西期、印支期岩浆岩的岩相学、岩石化学和地球化学特征,并基于火成岩构造组合探讨了区内在该时期的大地构造演化。加里东期岩浆岩有包尔汗图群火山岩和巴特敖包侵入岩,时代为奥陶纪。是与俯冲作用有关的一套岛弧型火成岩组合。在火山岩中首次识别出与弧前拉张作用有关的苦橄岩、玻安岩及具MORB 性质的玄武岩,并确认为SSZ 型;认为巴特敖包侵入岩为adakites;为本区早古生代构造演化提供了新的依据。早华力西期发育有早泥盆世的蛇绿岩组合、泥盆纪的HKCA 花岗岩和正长岩。早泥盆世蛇绿岩为SSZ 型,岩石组合有变质橄榄岩、堆晶辉长岩、玻安岩和枕状玄武岩,洋盆具弧后盆地性质。泥盆纪花岗岩和正长岩总体为HKCA 系列,形成于后碰撞环境。中华力西期有早石炭世的MKCA 花岗闪长岩、碱长花岗岩和晚石炭世的正长岩。早石炭世侵入岩为与洋壳俯冲有关的岛弧火成岩。晚石炭世正长岩具板内或后造山伸展岩浆特征,由于空间分布上的相隔较远,与早石炭世侵入岩的关系不确定。晚华力西期岩浆岩主要分布于北带和南带。北带有早二叠世岛弧型火山岩和侵入岩、早中二叠世的大石寨组火山岩和同期的侵入岩。大石寨组火山岩岩相学和岩石化学显示其中有石英角斑岩存在,证明有海底岩浆喷溢。早中二叠世的大部分酸性岩浆岩(流纹岩和花岗岩)为过铝特点(A/CNK>1.1),具同碰撞-后碰撞特征;总体北带岩浆岩环境比较复杂,可能反映了从岛弧一直到后碰撞。南带该期岩浆岩最为发育,早二叠世苏吉组火山岩、早中二叠世侵入岩,反映了活动大陆边缘构造背景;中晚二叠世花岗岩具铝质A 型花岗岩特点,反映了造山后伸展背景。印支期岩浆岩在中带和南带大面积分布。中带为早三叠世的辉长岩、石英闪长岩、二长花岗岩和正长花岗岩,形成于俯冲环境;南带为晚三叠世SP 花岗岩更多还原

【Abstract】 Baiyun’ebo–Mandula region of Inner Mongolia crossovers the boundary between North China Platform and Xingmeng Orogenic belt, and one of its notable characteristics is having large volume of Paleozoic-Mesozoic magmatic rocks. Based on 1/250000 regional geological survey of Baiyun’ebo and Mandula, the petrography, petrochemistry and geochemistry of Paleozoic-Mesozoic magmatic rocks are studied in detail. The geotectonic evolution in this region is discussed on the basis of igneous petrotectonic assemblages. Caledonian magmatic rocks include volcanic rocks and intrusive rocks which were erupted or intruded in Ordovician. Those rocks are subduction-related assemblages. Picrites, boninites and MORB-like basalts are identified for the first time which may relate to the extension of forearc basin and were formed in SSZ (supra-subduction zone) setting. All of those provide new clues for the early Paleozoic geotectonic evolution. Early Hercynian magmatic rocks include early Devonian Oceanic assemblages, Devonian HKCA granites and syenites. Oceanic assemblages were formed in SSZ setting, and have metamorphic peridotites, gabbros having cumulus textures, boninites and pillow basalts. The ocean has the characteristic of back arc basin. Devonian granites and syenites are HKCA series in general and may be formed in pos-collision setting. Middle Hercynian igneous include early Carbonic MKCA granodiorites, alkalifeldspar granites and late Carbonic syenites. Early Carbonic granitoids are subduction-related igneous. Late Carbonic syenites have the characteristics of within-plate or post-orogeny magmatic rock, and may have no relationship to the early Carbonic granitoids because of the更多还原