【作者】 刘加强；

【导师】 王训练；

【作者基本信息】 中国地质大学（北京） ， 古生物学与地层学， 2013， 博士

【摘要】 本文定位于滇东南铝土矿主要成矿期构造背景和岩相古地理研究。结合前人资料及相关研究成果,以野外露头、钻孔、探槽为主要依据,运用沉积学、古生物学、岩相古地理学、层序地层学等,采用地球化学的手段对研究区构造背景进行系统研究,建立研究区晚二叠世吴家坪早期沉积相模式,并对滇东南铝土岩主要成矿期—晚二叠世吴家坪早期岩相古地理进行了系统研究。取得以下主要认识：1、通过对研究区及邻区建水、桂西地区中、晚二叠世火成岩地球化学研究,认为晚二叠世早期研究区处于弧后盆地的构造环境,受峨眉山地幔柱和洋壳俯冲的双重作用。对铝土矿和碎屑岩综合研究认为研究区铝土矿和顶部砂岩的源岩为峨眉山玄武岩,而底部的砂岩的源岩则为长英质岩石；硅岩地球化学特征反映其受到一定程度热液的影响,表明晚二叠世时该地区受峨眉山地幔柱或(和)断裂的共同影响。2、在前人对研究区晚二叠世吴家坪期岩相古地理研究基础上,结合研究区吴家坪阶下部岩石类型和组合特征、沉积特征、沉积相类型,认为滇东南地区晚二叠世吴家坪早期处于滨岸-陆表海环境,研究区吴家坪早期含铝土岩的沉积相模式为包括局限浅海和低能海岸两种类型低能泥质海岸的沉积相模式,并进一步划分沼泽、潮坪、局限浅海上部、局限浅海下部亚相及潮上带、潮间带、潮下带微相。3、运用“单因素分析多因素综合作图”法,对研究区晚二叠世吴家坪早期岩相古地理进行研究,研究认为：研究区西南部为屏(边)马(关)—越北古陆,西缘存在康滇古陆,共同为研究区提供物源,并导致研究区沉积相带呈“L”型展布,沉积相带变化的方向为由南西向北东海水逐渐变深；晚二叠世吴家坪早期沉积开始时,文山天生桥附近地区的古地形可能相对低洼,导致该区沉积厚度较大,构成盆地的沉积中心。更多还原

【Abstract】 This paper focuses on the geological setting and palaeogeography of the main metallogenic epochs of southeastern Yunnan. On the basis of the summary of previous research and related research achievements, this paper regards lots of outcrop section, drill holes and renches as the main basis, based on the theory of sedimentology, palaeontology, palaeogeography and sequence stratigraphy tectonics, by using of geochemistry, the tectonic setting of the studied area was studied systematically. On this basis, build up sedimentary facies model of the Late Permian of Early Wuchiapingian in this district, and then We systematic study the palaeography of Early Wuchiapingian.The main results as follows:1. Based on geochemical characteristics of volcanic rocks from studied area and its neighboring areas, i.e. Jianshui of southeastern Yunnan and Western Guangxi Province, the author draw a conclusion that the tectonic setting was influenced by both Emeishan mantle Plume and the subduction of oceanic crust, resulting its tectonic setting of back-arc; the geochemical characteristics of sedimentary rocks and bauxites results suggest that the Emeishan basalts, granites are the main source of material for the bauxite ores and siltstone, sandstones, respectively. The precursor rocks for silty mudstone are basalts and granites; the geochemical characteristics of cherts implies the dual effects of both Emeishan mantle Plume and rupture.2. On the basis of predecessors study, combining with the rock styles and their combinatorial feature, depositional features, facies types, the paper puts forward a sedimentary facies model of offshore-epicontinental sea of the Late Permian of Early Wuchiapingian in this district.The types of subfacies and micro-facies of each sedimentation have been distinguished further, including swamp, supratidal, intertidal, subtidal and restricted shallow sea subfacies and micro-facies.3. On the basis of the quantitative and qualitative data of outcrops and well sections, according to the single factor analysis and multifactor comprehensive mapping method, the lithofacies palaeogeography of Wujiaping Early Stage of Late Permian in Wenshan, Southeast Yunnan, was studied and mapped, the research results as following:Kangdian old land and North Vietnam old land located to the west and Southeast of Wenshan during Late Permian Wuchiaping age; Kangdian old land and North Vietnam old land were the common material sources provider; the sediments of Tianshengqiao deposited in low-lying peat, which constituted the depocenter.更多还原