Metamorphic rocks in central Tibet: Lateral variations and implications for crustal structure
Metamorphic rocks in central Tibet: Lateral variations and implications for crustal structure
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DOI：
10.1130/b30154.1
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发表时间：
2011-03
影响因子：
4.9
通讯作者：
A. Pullen;P. Kapp;G. Gehrels;L. Ding;Qinghai Zhang
中科院分区：
文献类型：
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作者：
A. Pullen;P. Kapp;G. Gehrels;L. Ding;Qinghai Zhang
通过对羌塘盆地变质岩的地质调查，我们对青藏高原中部地壳的年龄、成分和结构的横向变化有了新的认识。先前的研究表明，羌塘地体中部东西向距离为1600 km的三叠纪构造混杂岩，在绿片岩相基质中含有蓝片岩和榴辉岩块体。新填图表明，该混杂岩南北向延伸距离超过150 km，接近北部早中生代金沙缝合带的痕迹。该混杂岩主要由古生代变质沉积岩和结晶岩组成，构造出露于早中生代正断层下盘的上古生界-中生代地层之下。这些发现支持了羌塘中部和北方地壳大部分由表壳岩组成的假设。杜格尔山脉
Insights about lateral variations in the age, composition, and structure of the central Tibetan crust are provided by geologic investigations of metamorphic rocks in the Qiangtang terrane. Previous studies have shown that a tectonic melange of Triassic age with blueschist- and eclogite-bearing blocks within a greenschist-facies matrix is exposed over an E-W distance of ∼600 km in the central Qiangtang terrane. New mapping shows that the melange extends over a N-S distance of ∼150 km, nearly to the trace of the early Mesozoic Jinsha suture in the north. The melange, exposed structurally beneath Upper Paleozoic to Mesozoic strata in the footwalls of early Mesozoic normal faults, is composed mostly of Paleozoic metasedimentary and crystalline rocks. These findings support the hypothesis that a large part of the central and northern Qiangtang terrane crust is composed of supracrustal rocks. The Duguer Range,