云南省个旧地区三叠系层序地层学研究及大地构造背景分析

发布时间：2018-05-04 13:51

本文选题：个旧地区 + 海相盆地　；参考：《昆明理工大学》2015年硕士论文

【摘要】：云南省个旧地区位于华南板块南缘处的右江盆地(或称南盘江盆地、滇黔桂盆地)之西南隅,并以生产锡矿而闻名中外。工作区位于云南省个旧市南部,前人对该区域进行了大量的地质填图及矿产勘查,但对地层层序特征的研究普遍较弱,因此本文以层序地层学、造山带地层学、岩相古地理学、板块学说等理论为指导,在前人研究的基础上,结合主干剖面的测制与区域构造背景,对个旧地区三叠系进行层序地层学研究,查明各层序的沉积相及沉积体系特征,并对所处右江盆地进行该时期大地构造背景的分析。总体上工作区内地层接触关系清楚,所涉及的三叠纪地层剖面包括三条实测剖面与三条前人测制剖面,包括三叠系下统冼马塘组(Tlx)与嘉陵江组(T1j)、中统个旧组(T2g)与法郎组(T2f)、下统把南组(T3b)与火把冲组(T3h)。现将其共分为3个二级层序,具体分为7个三级层序,由2个陆棚边缘体系域(LST)、6个海侵体系域(TST)和7个高位体系域(HST)组成,层序界面多为岩相转换面与火山事件界面,沉积体系包括碳酸盐台地沉积体系、浅海陆棚沉积体系以及滨岸沉积体系。结合三叠纪地层的沉积相环境以及对大地构造背景的整合分析,认为右江盆地为印支运动的产物,为受古特提斯构造与滨太平洋构造作用下的复合盆地,经历由志留纪末期开始的陆内裂谷盆地阶段—被动边缘裂谷盆地—弧后裂谷盆地—前陆盆地阶段受充填消亡的演化过程,其浅海相台地不断消亡并最后接收陆源沉积物的充填。
[Abstract]:Located in the southwestern corner of the Youjiang basin (or the Nanpan River Basin, the Yunnan Guizhou Guangxi basin) in the southern edge of the Southern China plate, the old area of Yunnan province is famous for the production of tin deposits. The working area is located in the southern part of the old city of Yunnan province. The predecessors have carried out a large number of geological mapping and mineral exploration in the region, but the study of the sequence sequence characteristics is generally weak. Therefore, based on the theory of sequence stratigraphy, orogenic belt stratigraphy, lithofacies palaeogeography, plate theory and so on, based on the predecessors' research, the sequence stratigraphy of the Triassic System in the old area is studied, the sedimentary facies and depositional system characteristics of each sequence are identified, and the Youjiang basin is located. The geodetic background of this period is analyzed. In general, the contact relationship between the interior layers of the working area is clear, and the Triassic stratigraphic sections involved include three measured sections and three previous measurement sections, including the lower Triassic Xian Ma Tong formation (Tlx) and the Jialingjiang group (T1j), the middle old group (T2g) and the franc group (T2f), and the lower Southern Group (T3b). T3h, which is divided into 3 two sequence sequences, is divided into 7 three order sequences, consisting of 2 continental margin system domains (LST), 6 transgressive system domains (TST) and 7 high position system domains (HST). The sequence interface is mainly the lithofacies transition surface and volcanic event interface, and the sedimentary system includes carbonate platform sedimentary system and shallow sea shelf depositional system. With the sedimentary facies of the Triassic strata and the integration of the tectonic setting of the Triassic strata, the Youjiang basin is considered to be the product of the Indo branch movement. It is a complex basin under the action of the ancient Tethys structure and the shore Pacific structure, which experienced the stage of the intracontinental rift basin from the late Silurian period to the passive marginal rift. The basin - back arc rift basin - foreland basin stage is affected by the process of backfilling and extinction, and its shallow sea platform is constantly disappearing and finally receives the filling of terrigenous sediments.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P534.51;P548

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