洋脊俯冲及其在新疆阿尔泰地区存在的可能证据  

Ridge Subduction and the Possible Evidences in Chinese Altay,Xinjiang

作　　者：沈晓明[1,2] 张海祥[1] 马林[1,2] 

机构地区：[1]中国科学院广州地球化学研究所同位素年代学与地球化学重点实验室,广东广州510640 [2]中国科学院研究生院,北京100049

出　　处：《大地构造与成矿学》2010年第2期181-195,共15页Geotectonica et Metallogenia

基　　金：国家自然科学基金(编号:40672057);国家重点基础研究发展规划项目(编号:2007CB411303)资助

摘　　要：本文综述了洋脊俯冲的研究历史与现状,论述了与洋脊俯冲相关的各种构造运动、岩浆活动以及成矿特点。同时,系统总结了阿尔泰南缘已报道的可能与洋脊俯冲有关的证据,如埃达克岩和富铌玄武岩、玻安岩、苦橄岩、A型花岗岩、双峰式火山岩、阿拉斯加型杂岩、酸性岩墙群等特殊的岩石类型,以及可能与洋脊俯冲相关的变质变形作用,认为洋脊俯冲模式可以合理的解释阿尔泰南缘的这些岩石组合以及变质变形作用。此外,分析了晚古生代阿尔泰南缘洋脊俯冲的时空分布,阐述了洋脊俯冲对中亚造山带陆壳增生及成矿的意义。Ridge subduction is a type of subduction that the spreading centre subducted into the trench and interacted with the subduction zone. Athough magma continues to be formed between the diverging plates,it will not cool sufficiently to solidify onto the trailing plate edges. Rather,magma generated will rise through the asthenospere and this may form a slab window and induce a series of special geological phenomena. Ridge subduction is obviously different from the common ocean crust subduction,it was early noted by geologists as the particular geological consequences and the important implications for geodynamics and metallogenesis. In this paper,we summarize the history and actuality of the researches for ridge subduction,and discuss the characteristics of various tectonic movements,magma activities and metallogenesis induced by ridge subduction. Chinese Altay,as a key part of the Central Asian Orogenic Belt （CAOB）,is distributed by a lot of geological records associated with ridge subduction. So we summarize the evidences of ridge subduction in this area,for example,adakite and Nb-enriched basalt （NEB）,boninite,picrite,A-type granite,bimodal volcanic rocks,Alaskan-type mafic-ultramafic complexes,acidic dyke swarm and some metamorphic rocks and deformation. A ridge subduction model can account for the formation of these rocks and coeval deformation. We also analyze the spatial and temporal distribution of the ridge subduction in Chinese Altay,and its implications for the continental growth and metallogenesis in CAOB.

关 键 词：洋脊俯冲 阿尔泰 陆壳增生 成矿 

分 类 号：P541[天文地球—构造地质学]