【作者】 孙泽轩；

【导师】 陈洪德；

【作者基本信息】 成都理工大学 ， 沉积学， 2007， 博士

【摘要】 本论文以外生后成砂岩型铀矿成矿理论为指导，通过系统收集滇西地区新生代盆地区域地质、遥感、物探、水文地质与水化学及铀矿床（点）等资料，开展有针对性的野外路线地质调查、放射性物探方法测量、深部钻探验证与室内分析测试，多学科综合研究相结合，重点研究了盆地盖层发育的沉积体系特征、层序地层特征、盆地沉积演化与盆山耦合特征、水文地质与水化学特征、氧化带发育特征与铀矿化特征，系统总结了滇西新生代盆地砂岩型铀矿成矿条件，建立了潜水层间氧化带砂岩型铀矿成矿模式。论文研究取得了以下创新性成果和认识：1．滇西新生代盆地的形成受腾冲微板块上泸水-瑞丽弧形走滑断裂带及其西部次级断裂带走滑活动的控制。根据不同地区走滑造山带走滑活动控制盆地沉积演化与构造演化作用的差异，将滇西新生代盆地划分为2种类型。沉积成盆阶段，北部腾冲地区与南部瑞丽地区走滑造山带走滑活动强烈程度的差异，导致了南北盆地盖层沉积体系发育类型与空间配置、火山活动强烈程度、湖盆发育频率的差异；改造盆地阶段，北部腾冲地区与南部瑞丽地区新生代盆地构造运动形式乃至构造运动强烈程度存在较大差异，从而引起了北部腾冲地区与南部瑞丽地区新生代盆地隆升剥蚀程度、火山活动强烈程度与地貌景观的差异。2．不同类型盆地氧化带发育类型与砂岩型铀矿成矿作用存在差异。北部腾冲地区新生代盆地盖层以发育潜水层间氧化作用为主，南部瑞丽地区新生代盆地盖层以发育潜水氧化作用为主，而滇西地区新生代盆地砂岩型铀矿与潜水层间氧化成矿作用关系密切。3．滇西新生代盆地砂岩型铀矿成矿期处于盆地构造强烈活动阶段，亦即构造层序界面的形成阶段。认为构造层序界面1（TSB₁）为含铀、含氧地下水向盖层深部渗流提供了快速通道，并提供了潜水层间氧化带的发育空间与砂岩型铀矿的储矿空间；构造层序界面2（TSB₂）与构造层序界面3（TSB₃）的形成与潜水层间氧化带砂岩型铀矿的成矿作用存在耦合关系。4．不同类型盆地和盆地演化不同阶段砂岩型铀矿成矿条件存在差异。砂岩型铀矿成矿最有利的是北部腾冲地区区域性隔水层发育、改造盆地阶段盆地持续隆升、发育潜水层间氧化成矿作用、存在大规模火山活动、深切割低山-丘陵-河谷阶地地貌的新生代盆地。5．本论文探讨了滇西新生代盆地潜水层间氧化带砂岩型铀矿成矿模式以及不同构造部位矿体空间定位模式。认为典型的潜水层间氧化带除具有与层间氧化带相似的舌状体前锋氧化还原界面外，在舌状体翼部亦形成上、下翼氧化还原界面，从而发育氧化带前锋与上、下翼3个板状或透镜状铀矿体，既不同于定位于层间氧化带前锋部位氧化还原界面附近的卷状矿体，也与定位于潜水氧化带底部氧化还原界面附近的层状、似层状矿体有所差异。并指出，在斜坡带，铀矿体定位于潜水层间氧化带前锋与上、下翼；在断陷带，铀矿体定位于潜水层间氧化带前锋与上翼。上述研究成果和认识不仅对滇西造山带内部发育的小型山间盆地砂岩型铀矿找矿勘探部署具有重要的指导作用，而且丰富和完善了具中国特色的砂岩型铀矿成矿理论。更多还原

【Abstract】 This dissertation was directed by the metallogenic theories of exogenic-epigenetic sandstone-type uranium deposits. By collecting datum of regional geology, remote sensing, geophysics, hydrology and hydrochemistry, uranium deposits and uranium occurrences systematically, developing field geologic investigation, radioactive geophysics method, drilling validation, inside test and combination with synthetical studies, and the central studies concentrated on the characteristics of depositional systems, sequence stratigraphy , evolvement of sedimentary basins and basin-mountain coupling , hydrology and hydrochemistry, oxidation zone and Uranium mineralization. the author summarized the metallogenic conditions on sandstone-type uranium deposits systematically, and established the metallogenic model of phreatic interlayer oxidation zone sandstone-type uranium deposits in Cenozoic basins Western Yunnan. The author acquired some innovative outcomes and recognitions:1. According to the difference of basin sedimentary evolvement and tectonic evolvement controled by strike-slip activity of orogen in different areas Western Yunnan, the author divided in 2 sorts of Cenozoic basins. In sedimentary basin stage, the degree of intense strike-slip activity of orogen was different, it brought difference in the types and space deployment of depositional systems, intense degree of the volcano activity and developable frequency of lacustrine basin.In reformed basin stage, the form even the intense degree of tectonic activity was different, and it brought difference in the degree of uplift and denudation, intense degree of the volcano activity and physiognomy.2. The types of oxidation zone and the metallogenic process are different in different sorts of basins. The cover of Cenozoic basins in northern Tengchong area mostly developed phreatic interlayer oxidation process, and the cover of Cenozoic basins in southern Ruili area mostly developed phreatic oxidation process, and the sandstone-type uranium deposits have relationship with phreatic interlayer oxidation metallogenic process in Cenozoic basins western Yunnan.3. The period of metallogenic process of sandstone-type uranium deposits corresponded with stage of violent activity of basin tectonic, that is to say, it corresponded with forming stage of tectonic sequence boundaries. It is considered that the tectonic sequence boundary one provided the seeped channels for ground water bearing O and U under the cover, and provided the developed spaces for phreatic interlayer oxidation zone, collected spaces for sandstone-type uranium deposits, and the forming of the tectonic sequence boundary two and the tectonic sequence boundary three were correlative with the metallogenic process of phreatic interlayer oxidation sandstone-type uranium deposits.4. The metallogenic conditions of sandstone-type uranium deposits are different in different sorts of basins and different stages of basin evolvement.The advantaged basins for prospecting sandstone-type uranium deposits are those basins that developed regional isolatable water layers, continued rising in reformed basin stage, developed phreatic interlayer oxidation metallogenic process, existed volcano activity and deep incised physiognomy being low mountain-hill-river valley terraces in northern Tengchong area..5. In this dissertation, the author discussed metallogenic model and the located model of uranium orebody in different tectonic position of phreatic interlayer oxidation zone sandstone-type uranium deposits in western Yunnan.It is considered, besides tonguelike vanguard oxidation-reduction interface like interlayer oxidation zone, it also developed oxidation-reduction interface in upper and lower limb inner the typical phreatic interlayer oxidation zone, thereby, it could develop 3 planar or lentoid uranium orebody in tonguelike vanguard, upper and lower limb along the interface of phreatic interlayer oxidation zone, it is neither similar to curly uranium orebody located in vanguard near by oxidation-reduction interface of interlayer oxidation zone, nor to stratiform and stratoid uranium orebody located in floor near by oxidation-reduction interface of phreatic oxidation zone. Moreover, the author pointed out, in slope belt, uranium orebody located in tonguelike vanguard, upper and lower limb along the interface of phreatic interlayer oxidation zone, and fault depression belt, uranium orebody located in tonguelike vanguard and upper limb along the interface of phreatic interlayer oxidation zone.Those innovative outcomes and recognitions acquired by the author will not be only provide with important function in deploying prospecting sandstone-type uranium deposits of the minitype intermontane basins developed inner orogenies belt in western Yunnan, further more, it perfected and enriched the theories of sandstone-type uranium deposits own in china.更多还原