新疆青河县博特一带变质岩原岩恢复研究

Reconstruction of protoliths of metamorphic rocks in the Bot segment of Qinghe county of Xinjiang,China

根据变质岩产出特征、主量元素岩石化学和微量元素特征,依据相关图解对研究区变质岩进行了原岩恢复,结果显示:蚀变火山岩的原岩为基性火山岩和中酸性火山岩,可能与板内裂解或者与板块俯冲作用相关的亏损型地幔岩浆有关,是同源岩浆演化的产物;热接触变质岩长英质角岩和角岩化闪长岩的原岩可能为中酸性火山岩。

The protoliths of the metamorphic rocks in the Bot section of Qinghe county of Xinjiang is reconstructed according to the occurrence of the metamorphic rocks,the petrochemical characteristics of the main elements and the trace elements in the metamorphic rocks and by means of related graphs.The result shows that the protoliths of those metamorphic rocks are basic volcanic rocks and neutral-acid volcanic rocks,which may be related to the cracking within the plate or the depleted mantle magma related to plate subduction,and they are the evolution products of cognate magma;the protolith of thermal contact metamorphic felsic hornfels and hornfels diorite may be neutral-acid volcanic rocks.