论文部分内容阅读
沅水流域处于扬子地台的中部偏南位置,其基底由冷家溪群和板溪群组成。呈北北东向的北京—郑州—常德深断裂带、呈北东东—北东向的贵阳—怀化深断裂带和呈北东向的都匀—宜昌深断裂带是本区主要的深断裂带。本区基性、超基性岩岩脉群的出露,从北向南可归纳为三个岩桨岩带。其中,深冲金伯利岩岩脉群在中间岩桨岩带中。在震旦系、三叠系和白垩系的碎屑岩层中分别找到金刚石,但金刚石砂矿富集于第四纪阶地的砾石层中。沉水流域各地段的金刚石物理性质有明显差别,足以说明它们来自不同的源区。这些事实表明,在沉水流域寻找新的金伯利岩是十分有希望的。
The Yuanshui River Basin is located in the central part of the Yangtze Platform in the southerly position, and its base consists of Lengjiaxi Group and Banxi Group. The north-northeast Beijing-Zhengzhou-Changde deep fault zone, the NE-NE-NE direction Guiyang-Huaihua Deep fault zone and the NE-trending Duyun-Yichang deep fault zone are the major deep faults in this area band. The basic and superbasic petrofacies of the area are exposed from north to south and can be grouped into three types of sternolith belt. Among them, the deep-kimberlite dikes are in the middle of the rock-slick belt. Diamonds were found in the Sinian, Triassic and Cretaceous clastic formations, respectively, but diamond sands were enriched in gravel layers of the Quaternary. The physical properties of diamonds in each section of the submerged basin are obviously different enough to indicate that they originate from different source areas. These facts show that it is very promising to find new kimberlites in the submerged basin.