CAJ | 학술논문

该文通过薄片鉴定、扫描电镜等手段，结合分析化验数据，分别对鄂尔多斯盆地纳岭沟地段和大营地段直罗组下段砂岩碎屑及填隙物的成分、含量及微观结构特征进行对比研究，确定微观特征差异并初步探讨差异原因，建立其与铀矿化的关系。研究表明，纳岭沟地段与大营地段，在碎屑成分和填隙物方面均存在一定的差异。纳岭沟地段碎屑含量高，而胶结物及粘土含量较低，这一方面表明纳岭沟地段相比大营地段更靠近物源，长石风化程度相对较低；另一方面，由于目的层埋深不同而导致的成岩强度的差异也是造成岩石微观特征差异的重要原因。基于对含矿砂岩微观特征的研究，笔者认为纳岭沟和大营地段与东胜皂火壕地段经历了基本相同的铀成矿作用，大致可分为早期主成矿和后期再改造两个阶段。造成绿色调砂岩的主要原因是由于后期油气还原蚀变而形成的绿泥石。在成矿过程中，方解石与铀矿物的沉淀有着密切的联系。这为下一阶段东胜西北部地区铀矿勘查预测提供了理论依据。
해문통과박편감정、소묘전경등수단，결합분석화험수거，분별대악이다사분지납령구지단화대영지단직라조하단사암쇄설급전극물적성분、함량급미관결구특정진행대비연구，학정미관특정차이병초보탐토차이원인，건립기여유광화적관계。연구표명，납령구지단여대영지단，재쇄설성분화전극물방면균존재일정적차이。납령구지단쇄설함량고，이효결물급점토함량교저，저일방면표명납령구지단상비대영지단경고근물원，장석풍화정도상대교저；령일방면，유우목적층매심불동이도치적성암강도적차이야시조성암석미관특정차이적중요원인。기우대함광사암미관특정적연구，필자인위납령구화대영지단여동성조화호지단경력료기본상동적유성광작용，대치가분위조기주성광화후기재개조량개계단。조성록색조사암적주요원인시유우후기유기환원식변이형성적록니석。재성광과정중，방해석여유광물적침정유착밀절적련계。저위하일계단동성서북부지구유광감사예측제공료이론의거。
In this paper, we examine the composition and content of interstitial material and the microscopic structure characteristics through the microscopic observations, scanning electron microscopy analyses combined with XRD data of the lower member of the Zhiluo Formation in Nalinggou and Daying areas. The microscopic characteristics were identified and preliminary discussion on the differences of sandstones from the two areas were made to establish the relationship between the microscopic characteristics of ore-hosting sandstone and uranium mineralization. Research results show that there is certain difference between the clastic composition and the interstitial material in Nalinggou and Daying areas. The sandstones in Nalinggou area have higher detrital content and lower cement and clay content as compared to that in Daying area. On one hand, Nalinggou area is located closer to the provenance as compared to Daying area, leading to the disintegration of feldspar. On the other hand, the differences of microscopic characteristics in ore-hosting sandstone resulted from the difference in the intensity of diagenesis that was caused by the depth of the lower member of the Zhiluo Formation. As mentioned above, we consider that Nalinggou and Daying areas experienced the same uranium ore-formation process as Zaohuohao area. The uranium mineralization can be divided into two stages, i.e., the early main mineralization and later reconstruction enrichment. And the green color of the sandstone came from the chlorites formed by the asending reduction fluids. In the process of mineralization, uranium minerals and calcite were precipitated simultaneously. The study results provide a theoretical basis for the uranium exploration in the northwest of Dongsheng area.