新疆西昆仑中太古界古陆核的确定及地质意义

Determination and Geological Significance of the Mesoarchean Craton in Western Kunlun Mountains,Xinjiang,China

原赫罗斯坦岩群为一套无序变质核杂岩,岩性为混合岩化花岗质片麻岩、紫苏辉石麻粒岩等。岩石组合及地球化学特征都具TTG岩石特征。采用LA-ICP-MS方法测定锆石U-Pb年龄值3137.3±4.1Ma,反映其时代为中太古代,代表赫罗斯坦杂岩原岩生成年龄。由此说明,塔里木南缘铁克里克地区存在太古宙大陆核,为新疆境内所发现的最古老岩系之一。

The Heluositan Rock Group （Complexes） is a kind of disordered metamorphic core complex, composed of migmatic granitic gneiss, hypersthene granulite, etc. Both of the rock association and geochemical characteristics have TTG rock features. By means of LA-ICP-MS U-Pb dating of the zircon from hypersthene granulite（1011AK PVI ZS2） in the Heluositan Complexes, an age of 3137.3±4.1Ma is determined, which should be the original rock age of the Heluositan Rock Group（Complexes）, i.e. the Heluositan Rock Group（Complexes） is Mesoarchean. It proves that there is an Archean continental nucleus in Southern Tarim, which is one of the earliest rock series found in Xinjiang.