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内蒙古乌拉特中旗地区在大地构造上横跨华北板块边缘和兴蒙造山带,区域基性岩体多以小岩株形式产出,侵入时代缺少可靠的资料.对乌拉特中旗哈达呼舒基性岩进行锆石U-Pb年代学、岩石地球化学以及Hf同位素研究,对其岩石成因和古亚洲洋板块俯冲作用的开始时间给予制约.哈达呼舒基性岩锆石LA-ICP-MS U-Pb定年结果表明,该岩体形成于晚寒武世(513±2Ma).在地球化学上,它们属于钙碱性系列,富集大离子亲石元素(如K、Rb、Ba),亏损高场强元素(如Nb、Ta、Zr、Ti)和LREE.岩石的ε_(Hf)(t)值为14.15~15.03,单阶段模式年龄(T_(DM1))为518~556Ma,与岩石原岩形成时代513Ma相近,认为其原始岩浆起源于亏损岩石圈地幔.综合区域同时代火成岩的研究成果,认为哈达呼舒基性岩体形成于古亚洲洋俯冲消减环境.
The Inner Mongolia Wulatezhongqi area traverses the edge of the North China Plate and the Xingmeng orogenic belt in the tectonic setting. Most of the regional basic rock mass is produced in the form of small rock mass, and there is no reliable data in the invasion age. U-Pb geochronology, geochemistry and Hf isotopic studies of zircons are used to control the onset time of the rocks and the subduction of the Paleo-Asian Ocean plate. The LA-ICP-MS U The results of -Pb dating show that the rock was formed during the Late Cambrian (513 ± 2Ma). In geochemistry, these rocks belong to the calcareous series and enrich large ion lithophile elements (such as K, Rb, Ba) The ε_ (Hf) (t) values of high field strength elements such as Nb, Ta, Zr, Ti and LREE are from 14.15 to 15.03 and from 518 to 556Ma for the single stage model (T_ (DM1) It is believed that the original magma originated from the depleted lithospheric mantle, and from the research on contemporaneous igneous rocks in the comprehensive area, it is concluded that the Hadamashu basic rock mass is formed in the subduction and subsidence environment of the Paleo-Asian Ocean.