山西省中生代侵入岩新认识

New recognition of Mesozoic intrusive rocks in Shanxi Province

根据区域地质调查资料,对山西省中生代侵入岩进行分析研究,将其划分为3个岩浆系列碱性偏碱性系列、亚碱性(基性)中性—中酸性系列和A型花岗岩(酸性)系列。碱性偏碱性岩系列形成于后碰撞构造环境,亚碱性(基性)中性—中酸性岩系列为大陆边缘弧和大陆岛弧及后造山构造环境,A型花岗岩系列为板内大陆裂谷或与地幔热点(地幔羽)有关的构造环境,板块俯冲作用为其提供了热能和含水溶液。大地构造分区划分为华北陆块区构造岩浆省(Ⅰ级),其中包括3个岩浆带(Ⅱ级)南兴蒙岩浆带、北秦岭岩浆带和华北东部岩浆带,每个岩浆带又可划分为2个岩浆亚带(2期岩浆作用)(Ⅲ级),各个岩浆亚带均具有板块俯冲造山带火成岩的特征和发育演化极性。该成果为解决板块构造登陆问题提供了借鉴。

Mesozoic intrusive rocks in Shanxi Province were divided into three magma series according to the regional geological survey,which were alkaline-subalkaline series,subalkaline(base-)—medium acid series,type A-granite(acid)series.Alkaline-subalkaline series were formed in the post-collision tectonic environment.Subalkaline(base-)—medium acid series were formed in continental island arc,continental edge arc and post-mountain tectonic environment.Type A-granite(acid)series were formed in the construction environment of in rift valley in the plate subduction or the mantle hotspots(mantle plume),and the heat and aqueous solution was provided by the plate subduction.The geotectonic division belongs to the tectonic magma provinces in North China Craton,including three magma belts(Grade II),which are southern Xingmeng magma belt,northern Qinling Mountains magma belt and eastern North China magma belt.Each magma belt can be divided into two subzones(Stage 2 Magma Action)(GradeⅢ),and each subzone has the characters of igneous rocks in the plate subduction zone and the evolution polarity.This achievement can provide some reference for landing problems of the plate structure.