泗洪、城岗地区金刚石及其指示矿物特征和供源方向

Characteristics and Origin of Diamond and its Indicating Minerals in Sihong and Chenggan Area, Jiangsu

泗洪、城岗地区晚新生代地层中选获大量金刚石及其指示矿物。这些金刚石与山东蒙阴金刚石原生矿和郯城砂矿中金刚石具明显区别。其指示矿物一部分来自含矿的金伯利岩。本文在泗洪、城岗地区晚新生代地层及其沉积特征一文的基础上,依据各方面对比资料进一步探讨金刚石及指示矿物的来源。

There have found many diamonds and its indicating minerals in the Late Cenozoic sediments in Sihong.Chenggang area,Northern Jiangsu Province. All these diamond are different from those found in the Menying primary diamond deposit and those in Tanchen placer deposit. The indicating minerals are from ore —bearing kimberlite. Based on the statistical data, the paper studies the characteristics of diamond and genetic origin of pyrope, chromite and picotite. The author proposes the direction of origin and that the diamond and indicating minerals in the area come from multiple—nearby origins after careful research on the pebble composition in sediments, paragenetic association of minerals and its maturity, abrasion of pebble, surface feature of pyrope, direction of shingle and imbricate arranged pebbles and paleogeographic characteristics. Through above analysis and studies. the paper points out two hopeful prospecting area for primary diamond deposit. One is between Tanchen — Lujiang wrench fault and Huaiying —Xiangshuikou fault and the other is betewwn Tanchen —Lujiang fault and Lianyungang — Suqian fault.