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OA北大核心CSTPCD

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.