安徽枞阳县黄龙桥地区隐爆角砾岩筒特征及其与铀成矿关系

安徽枞阳黄龙桥地区隐爆角砾岩筒地处庐枞盆地黄梅尖A型花岗岩体内，是岩体内发育的规模最大、最为典型的隐爆角砾岩筒。文章在详细的野外地质调查、物化探测量和钻孔岩心地质编录的基础上，通过显微岩石学、元素地球化学特征研究，分析其地质特征并探讨其与铀成矿的关系。分析研究表明：隐爆角砾岩具有角砾成分杂、隐爆作用强度大、“隐爆源”埋藏深特点，其自身并不含有铀矿化现象，铀元素平均含量远远低于石英正长岩；ΣREE为293.16×10-6~453.45×10-6，LREE/HREE为6.71~11.00，δCe为0.89~1.02，δEu为0.46~0.57，呈现较明显的负Eu异常，稀土元素配分模式呈右倾斜型，具有轻稀土分馏明显，重稀土分馏不明显的特点；隐爆角砾岩内部发育的大量赤铁矿形成于岩浆“隐爆”作用之前，铀成矿作用发生在隐爆角砾岩筒形成之后，推测隐爆角砾岩爆发时间在124~115 Ma；隐爆角砾岩筒主要为铀成矿提供了重要的导矿通道，外围具有较好的铀矿找矿潜力，而其深部具有寻找铁矿的潜力。

Characteristics of cryptoexplosive breccia pipe and their relationship with uranium mineralization in the Huanglongqiao area of Zongyang County, Anhui Province

The cryptoexplosive breccia pipe in the Huanglongqiao area of Zongyang County, Anhui Province is located within the Huangmeijian A-type granite body of the Luzong Basin. It is the largest and most typical hidden explosive breccia pipe developed within the rock mass. On the basis of detailed field geological surveys, geophysical and geochemical surveys, and geological logging of drilling cores, this work analyzed its geological characteristics and explored its relationship with uranium mineralization through microscopic petrology and elemental geochemistry characteristics. The cryptoexplosive breccia has mixed breccia composition, strong hidden explosive effect, and deep burial of cryptoexplosive sources. It does not contain uranium mineralization itself, and the average uranium element content is much lower than that of quartz syenite; ΣREE is between 293.16×10-6 and 453.45×10-6, LREE/HREE is between 6.71 and 11.00, δCe is between 0.89 and 1.02, and δEu is between 0.46 and 0.57, indicative of significant negative Eu anomalies. The rare earth element distribution pattern shows a right-inclined pattern, with obvious light rare earth fractionation and unclear heavy rare earth fractionation. A large amount of hematite developed within the hidden explosive breccia was formed before the magmatic "cryptoexplosive" process, and uranium mineralization occurred after the formation of the cryptoexplosive breccia pipe. The explosion time of the cryptoexplosive breccia was inferred to be between 124 and 115 Ma. Cryptoexplosive breccia pipe mainly provides important conduits for uranium mineralization, with good potential for uranium exploration in the periphery and iron ore exploration in the deep part.