某产铀岩体锆石的标型特征及其地质意义

Typomorphic Characteristics of Zircon from a Uranium-bearing Rock Body and Their Geological Significance

某岩体为一产铀的加里东期复式岩体。本文研究了该岩体中副矿物锆石的形态、包体和环带及其延长度、粒度的变化,将其与围岩中副矿物锆石进行对比并结合岩体中锆石的稀土元素地球化学特点,表明该岩体是区域上的沉积变质岩重熔交代的产物。笔者还从岩体中锆石的含铀性,ZrO_z/HfO_2值与岩石中Na_2O的关系探讨了成矿中铀和钠的来源,并从副矿物锆石的标型方面提出了产铀岩体的评价标志。

The J rock body formed in Caledonian period mainly consist of greyish white medium-coarse grained biotite diorite granite and yellowish red porphyritic biotite granite. Through the study on inclusions, length/ width ratio, grain size, rare earth, uranium and thorium of zircon and other accessory minerals, the authors consider that the original rocks of the J rock body are sedimentary metamorphic rocks.The rich uranium, rich HREE in zircon and the hydrothermal type accessory mineral assemblage of the rock body provide basis for the evaluation of uranium potential in the studied area.