论文部分内容阅读
中国大陆科学钻探工程使用石油大学研制的岩心地面伽马测量仪对主孔2000m岩心进行了连续测量,并记录峰、谷的伽马值及其对应的岩性、构造和矿化等特征。通过系统测量,建立了主孔2000m自然伽马值剖面,发现榴辉岩具有较低的伽马值,并从榴辉岩→角闪岩→花岗片麻岩,伽马值逐渐增大。伽马值与变质岩的岩性具有明显的对应关系。并从放射性元素U、Th和K含量的角度来看岩石中放射性元素的变化规律,探讨这些元素变化的成因,指出变质基(中)性岩原岩反映的岩浆岩成因,不同于变质泥质沉积岩;岩石高Th/U比值与岩石曾经经历了近地表环境有关。主孔深变质岩自然伽马测量的系统研究对主孔岩心深度归位、探讨岩石成因和区域岩石圈热状态和大地构造演化具有重要的作用。
The Chinese Continental Scientific Drilling Project used the core-ground gamma meter developed by the University of Petroleum to measure the 2000m core of the main hole continuously and record the gamma values of the peaks and valleys and their lithology, tectonics and mineralization. Through the systematic measurement, a 2000 m natural gamma ray profile of the main hole was established, and the eclogite was found to have a lower gamma value. From eclogite to amphibolite to granite gneiss, the gamma value gradually increased. There is a clear correspondence between gamma value and lithology of metamorphic rocks. The changes of radioactive elements in rocks from the perspective of the content of U, Th and K of radioactive elements are discussed. The causes of the changes of these elements are discussed. The origin of metamorphic rocks is different from that of metamorphic muddy sedimentary rocks ; The rocky high Th / U ratio has been associated with rock near-surface environments. The systematic study of the natural gamma ray measurement of the main deep pluton plays an important role in determining the core depth of the main hole and exploring the genesis of the main rock and the thermal state of the lithosphere and the tectonic evolution of the area.