津巴布韦奇拉色卡矿区金刚石古砂矿地质特征及成因

An analysis of geological characteristics and genesis of ancient diamond placer ore in Cherokee mining area of Zimbabwe

通过对津巴布韦奇拉色卡矿区金刚石古砂矿的地质特征、矿层特征、赋矿规律等的研究,建立了该区矿床勘查模型。研究表明,该区构造上处于太古宙津巴布韦克拉通东部边缘,西部紧邻林波波造山带、莫桑比克造山带,而林波波带为重要的金刚石产地,该区处于金刚石古砂矿成矿的有利位置;矿层赋存于中元古代乌肯多群砂砾岩组沉积岩中。该区金刚石古砂矿为沉积型金刚石古砂矿类型,属滨海环境沉积建造。在中元古代,原生矿中的金刚石被风化剥蚀出来,经流水的搬运,在滨海地区沉积,固结形成金刚石古砂矿床。津巴布韦奇拉色卡矿区金刚石古砂矿的发现及研究对指导中国境内寻找金刚石古砂矿具有重要的意义。

The authors studied geological characteristics, seam features and regularity of Cherokee ancient diamond placer ore of Cherokee mining area in Zimbabwe and then established the exploration model of the ore deposits in this area. It is shown that the region is structurally located at the eastern edge of the Archean craton in Zimbabwe, neighboring the Limpopo orogenic belt and the Mozambican orogenic belt in the west, and the Limpopo belt is an important diamond producing area. The area is in a favorable position for the mineralization of ancient diamond sand ore. The ore deposits occur in sand conglomerate of Proterozoic Ukendo Group, which belongs to sedimentary rocks. The diamond ore in this area is of sedimentary origin and belongs to the coastal environment structure.In the Middle Proterozoic period,the diamond in original mineral was stripped away by the weathering and carried by wind or water, then it deposited in the coastal area. The discovery and study of Cherokee ancient diamond placer ore in Zimbabwe have important guiding significance for finding more ancient diamond placer ores in China.