| 粤北长江铀矿田棉花坑断裂、油洞断裂特征及其与铀成矿关系 |
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| 引用本文： | 陈柏林,高允,申景辉,曾广乾.粤北长江铀矿田棉花坑断裂、油洞断裂特征及其与铀成矿关系[J].地质力学学报,2022,28(3):367-382. |
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| 作者姓名： | 陈柏林 高允 申景辉 曾广乾 |
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| 作者单位： | 1.中国地质科学院地质力学研究所, 北京 100081 |
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| 基金项目： | 国家重点研发计划项目（2017YFC0602602，2016YFC0600207）；中国地质科学院地质力学研究所基本科研业务费专项（JYYWF20180602） |
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| 摘 要： | 长江铀矿田位于广东仁化县，是中国华南地区最重要的硬岩型铀矿田。铀矿田内发育北北西（近南北）向含矿构造和北东东向棉花坑断裂及北西西向油洞断裂。棉花坑断裂、油洞断裂与铀成矿的关系涉及到矿田控矿构造格局构建和进一步找矿预测等关键问题。通过精细野外地质调查，重点研究棉花坑断裂、油洞断裂与北北西（近南北）向含矿断裂的相互关系，特别是断裂构造发育的特点和相互配套关系，取得如下认识:棉花坑断裂为脆性断裂破碎带，以未胶结的含有磨圆的花岗岩角砾的构造角砾岩和断层泥为特征，线性构造和负地貌特征明显，属于成矿后压扭性断裂，断错铀矿体和铀矿化带，但位移不大；油洞断裂为脆性破碎带，具有线性构造和负地貌特征，为北北西（近南北）向控矿构造的伴生张扭性断裂，并局部被其后的基性岩脉充填，它不是高级序控矿断裂，仅仅起局部含矿构造作用；油洞断裂带附近的韧性变形不是油洞断裂的连续韧性变形带，而是油洞岩体内小规模、零星不规则、多方向韧性变形的一部分；基于含矿构造呈北北西（近南北）向的展布特征，矿田内进一步的找矿方向不是沿着棉花坑断裂或油洞断裂的方向，而是沿着北北西（近南北）向含矿构造及现有矿化带的走向和倾向深部，在现有矿带间空白区的深部也很可能存在隐伏矿带。
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| 关 键 词： | 棉花坑断裂 油洞断裂 控矿构造 找矿方向 长江铀矿田 |
| 收稿时间： | 2021/7/15 0:00:00 |
| 修稿时间： | 2021/10/5 0:00:00 |
Characteristics of the Mianhuakeng fault and Youdong fault and their relation to uranium mineralization in the Changjiang uranium ore field, northern Guangdong |
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| CHEN Bailin,GAO Yun,SHEN Jinghui,ZENG Guangqian.Characteristics of the Mianhuakeng fault and Youdong fault and their relation to uranium mineralization in the Changjiang uranium ore field, northern Guangdong[J].Journal of Geomechanics,2022,28(3):367-382. |
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| Authors: | CHEN Bailin GAO Yun SHEN Jinghui ZENG Guangqian |
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| Affiliation: | 1.Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China2.Key Laboratory of Paleomagnetism and Tectonic Reconstruction of Natural Resources, Beijing 100081, China |
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| Abstract: | The Changjiang uranium ore field, located in Renhua county of Guangdong province, is the most important granite-type uranium ore field in southern China. There developed the NNW-trending (nearly SN-trending) ore-bearing fault structures, NEE-trending Mianhuakeng fault and NWW-trending Youdong fault. Understanding the characteristics of the Mianhuakeng fault and the Youdong fault and their relation to uranium mineralization is conducive to the building of ore-controlling structure system and further prospecting for uranium deposits. We carried out detailed field investigations, and focused on the analysis of the correlation between the Mianhuakeng fault, Youdong fault and NNW-trending (nearly SN-trending) ore-bearing faults, especially the development characteristics of fault structures and their combination with each other. Our key findings are as follows. (ⅰ) The Mianhuakeng fault is a brittle fracture belt, characterized by uncemented tectonic breccia and fault gouge containing well-rounded granite rubbles. It has obvious linear structures and negative geomorphic features, belonging to a post-mineralization compresso-shear fault, and it dislocates uranium ore body and uranium mineralization zone with small displacement; (ⅱ) The Youdong fault is a brittle fracture zone with linear structures and negative landforms. It is a tensional-torsional fault associated with NNW-trending (nearly SN-trending) ore-controlling structure and partially filled by subsequent mafic dikes. It is not a high degree ore-controlling fault and only plays a role of local ore-bearing structure; (ⅲ) There are several small ductile deformations near the Youdong fault, not that they formed a continuous ductile deformation belt resulting from the Youdong fault, but that they are ductile deformations inner the Youdong granite body with small scale, different strike and sporadic occurrence. (ⅳ) Based on the distribution of NNW-trending (nearly SN-trending) ore-bearing fault structures, the further prospecting for uranium deposits should be not along the Meihuakeng fault and Youdong fault, but along the NNW-trending (nearly SN-trending) fault belt, concentrated on the strike extending area and dipping deep area. In the meantime, there is a good chance for concealed ore zone at the surface and shallow parts of the vacancy for prospecting between existing ore zones. |
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| Keywords: | Mianhuakeng fault Youdong fault ore-controlling structure further prospecting for uranium deposits Changjiang uranium ore field |
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