阿尔金山中段苏吾什杰岩体(群)地质特征
The geological features of Suwushijie rockbody (group) in Altyn Tagh middle-zone
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摘要: 分布于阿中地块中浅变质岩隆起带之上的苏吾什杰岩体(群),为一规模较大的复式岩体,不同岩石类型之间接触关系清楚,由早到晚其侵位顺序为辉长-辉绿岩→闪长岩→似斑状花岗闪长岩→细粒二长花岗岩→似斑状中粗粒二长花岗岩,总体显示成分演化的特点,亦具有结构演化;岩石地球化学资料研究证明,该岩体(群)花岗岩与同碰撞型花岗岩(S-COLG)相似,显示壳源和壳幔混合源花岗岩特点;依据同位素测年结果,确定其侵位时代为早古生代晚期,岩体形成与板块作用相关连。Abstract: The Suwushijie rockbody (group) distributed on the meso-epimetamorphic uplift area of the AZhong massif is a large scale multi-body,and contact relationship between different types of rocks is clear.Their invaded order from early to late is gabbro-diabase → diorite → porphy roid granodiorite → fine granular adamellite → porphyr oid medium-coarse-grained adamellite.As a whole,the characteristics of components and tectonic evaluation have been showed in this order mentioned above.The lithog eochemical data proves that this rock group is similar to SCOLG and shows characteristics of source-mixed granite from mantle source rock and crust source rock.Isotope age indicat es that the invaded age of this group is in late period of Early Paleo zoic and relates to subduction of the subducting plate.