东昆仑南坡俯冲增生杂岩楔中纳赤台群物质组成特征

发布时间：2018-03-26 09:19

本文选题：东昆仑南坡俯冲增生杂岩　切入点：奥陶纪—志留纪　出处：《地质通报》2017年Z1期

【摘要】：东昆仑的形成经历了长期的构造演化、地体拼贴、碰撞及复合造山的动力过程。奥陶纪—志留纪昆中洋由南向北俯冲形成典型的东昆仑南坡俯冲增生杂岩楔,其中发育的纳赤台群物质组成复杂,也是该带主要的组成物质。通过野外详细调查,发现纳赤台群物质由洋中脊-洋岛环境下的含蛇绿岩残片组分及远洋泥钙质沉积、具有浊积岩特征的大陆斜坡次深海-深海相物质、前陆盆地复理石沉积组合、火山岛弧环境下的物质组合等构成。不同岩石组合间多为断层后韧性剪切接触,岩石构造变形十分强烈,不同岩块间时代跨度大,所处的构造环境迥异。在长期俯冲过程中,将不同的物质在东昆仑陆块边缘以不同规模,形态各异的岩片、岩块样式拼贴或堆垛在一起。
[Abstract]:The formation of East Kunlun has undergone a long period of tectonic evolution, orogenic collage, collision and composite orogeny. The Ordovicic-Silurian mid-Kun Ocean subducted from south to north to form a typical subduction and accretive complex wedge on the southern slope of East Kunlun. The material composition of the developed Nachitai group is complex, and it is also the main component of the belt. Through the detailed field investigation, it is found that the material of the Nachitai group is composed of ophiolite fragments and pelagic mudstone calcareous deposits in the mid-oceanic ridge-oceanic island environment. The subdeep-sea and deep-sea facies material of continental slope with turbidite characteristics, the assemblage of tectonite deposits in Foreland basin, and the material assemblage in volcanic island arc environment are all composed of subdeep-sea and deep-sea facies, and most of the different rock assemblages are post-fault ductile shear contact. The tectonic deformation of rock is very strong, the age span of different rock masses is large, and the tectonic environment is very different. In the long term subduction process, different materials are divided into different scales and different shapes at the edge of the East Kunlun land block. Pieces of rock form collage or stacking together.
【作者单位】：青海省地质调查局;青海省地质调查院;
【基金】：中国地质调查局项目《青海1∶25万布伦台、大灶火幅区调修测》(编号:1212011121187)
【分类号】：P587

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