摘要
华南中-新生代红盆与热液铀矿具有密切的关系。文章通过对中-新生代红盆的空间分布、沉积特征、形成条件、形成时代和演化特征的总结,研究了红盆与热液铀矿的空间、时间和成因联系,探讨了两者的动力学机制。研究认为,华南中-新生代红盆演化可划分为6个阶段:早白垩世晚期断陷沉积阶段、早白垩世晚期-晚白垩世早期抬升剥蚀阶段、晚白垩世早期断陷沉积阶段、晚白垩世中期抬升剥蚀阶段和晚白垩世晚期-古近纪坳陷沉积阶段、古近纪末萎缩封闭阶段;红盆与热液铀矿具有时空双重叠特征,两者在空间上共(伴)生、时间上重叠,其中3个拉张下陷沉积阶段与热液铀成矿3个主成矿期高度重合;两者都受区域控盆断裂带控制,都是在岩石圈减薄事件的构造背景下形成的,红盆参与了热液铀成矿作用,控盆深断裂带成为深部高温还原性含铀热液向上运移、浅部红层含铀淋滤流体向下运移的通道,两种流体在断裂带中混合,在物理化学条件急剧变化过程中,铀析出、富集成矿;两者是岩石圈伸展减薄事件作用于浅部地壳的两种地质作用形式,其共同的动力学机制为:受古太平洋俯冲作用变化的影响,地幔对流重建-软流圈物质的上涌填充,致使华南陆块发生岩石圈减薄事件。
The Mesozoic and Cenozoic red basins in South China are closely related to hydrothermal uranium deposits.The authors summarized the spatial distribution,sedimentary characteristics,formation conditions,formation times and evolution characteristics of the Mesozoic and Cenozoic red basins,studied the spatial,temporal and genetic relationships between the red basins and hydrothermal uranium deposits,and discussed the dynamic mechanisms of the two.The research showed that:1)The evolution of the Mesozoic and Cenozoic red basin in South China can be divided into six stages:the late Early Cretaceous rift deposition stage,the late Early Cretaceous-early Late Cretaceous uplift and denudation stage,the early Late Cretaceous rift deposition stage,the mid-Late Cretaceous uplift and denudation stage,the late Late Cretaceous-Paleogene depression deposition stage,and the late Paleogene shrinkage and closure stage.2)The red basin and hydrothermal uranium deposit have the characteristics of double overlapping in space and time.3)They are co-occurring in space and overlapping in time.The three stages of extensional subsidence and sedimentation are highly coincident with the three main mineralization stages of hydrothermal uranium mineralization.4)Both of them are controlled by the regional basin-controlling fault zone,which was formed under the tectonic background of lithosphere thinning event.The red basin participated in hydrothermal uranium mineralization.The basincontrolling deep fault zone became a channel for the upward migration of deep high-temperature reductive uranium-containing hydrothermal solution and the downward migration of uranium-containing leaching fluid from shallow red beds.The two fluids mixed in the fault zone,and uranium separated out and enriched into ore during the rapid change of physical and chemical conditions.5)They are two geological processes in which lithosphere extension and thinning events act on the shallow crust.Their common dynamic mechanism is the mantle convection of reconstruction-upwelling
作者
胡志华
林锦荣
陈柏林
陶意
王勇剑
HU Zhihua;LIN Jinrong;CHEN Bailin;TAO Yi;WANG Yongjian(CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;CGNPC Uranium Resources Co.,Ltd.,Bejing 100029,China)
出处
《铀矿地质》
CAS
CSCD
2022年第2期221-237,共17页
Uranium Geology
基金
国家重点研发计划项目(编号:2017YFC0602600)
国家自然科学基金面上项目(编号:41573051)联合资助。
关键词
中-新生代红盆
热液铀矿
时空双重叠
动力学机制
华南
Meso-Cenozoicred basin
hydrothermal uranium deposit
double overlap of time and space
dynamic mechanism
South China
