华南东部中新生代火山岩型铀矿成矿规律、勘查模式及找矿远景

METALLOGENEITC REGULARITY EXPLORATIONMODEL AND PROSPECTING POTENTIAL OF THE MESOCENOZOIC VOLCANIC TYPE URANIUM DEPOSITIN THE EAST OF SOUTH CHINA

中新生代时期，华南东部地壳经历了挤压－松驰拉张－局部裂解的演化过程。相应地发育３期火山活动，构成初火山族回、主火山旋回和破火山旋回。破火山使回出现双峰式岩套，标志着已进入胚胎型裂谷演化阶段。火山岩型铀矿具有破火山族回成矿、破火山旋回活动带控矿、二次迭加富集特性，可称其为破火山系列新不整合脉型铀矿。划分为体型、层型和脉型３种形态类型和相应的勘查模式。华南东部破火山系列新不整合脉型铀矿具有巨大的找矿潜力，在花岗岩基底上发育的破火山旋回构造－岩浆杂岩区，是今后寻找大型铀矿的有利靶区。

During the Meso-Cenozoic era, the crust in the east of South China experienced an evolutional process of compression-relaxed extension-local disintegration, correspondingly, threeperiods of volcanic activity were developed,forming initial volcanic cycle, principal volcaniccycle and caldera volcanic cycle. The caldera volcanic cycle was expressed as a 'bimodaltype'rock suite,indicating the entering of the region into an evolutional stage of new embryonic rifting. The volcanic type uranium deposit is characterized by ore-formation duringcaldera volcanic cycle,ore control by the mobile belt of caldera volcanic cycle and double superposition and concentration, and it can be summarized as a new unconformity-related typeuranium deposit of caldera volcanic series, which is divided into three morphological types:body type,layer type and vein type and relevant exploration models are proposed. The newunconformity-related type uranium deposits of the caldera volcanic series in the east of SouthChina have a great prospecting potential. The tectonomagmatic complex area of the calderavolcanic cycle developed on the granite basement is the favourable target area in searching forlarge uranium deposits from now on.