粤北大宝山矿区中生代叠加褶皱特征及其地质意义

发布时间：2018-06-30 10:43

本文选题：叠加褶皱 + 陆内变形　；参考：《科学技术与工程》2017年04期

【摘要】：大宝山矿区位于南岭地区南部,中生代印支期-燕山期至少发生了两期褶皱作用,清楚地记录了自身的构造变形历史;为了解大宝山矿区构造演化提供了非常有利的条件。通过矿区内褶皱、石英脉、劈理、膝褶等变形构造的分析,首次识别了矿区内两个世代不同方向的褶皱构造的横跨叠加型式。发现早期褶皱(轴面走向NW-NNW向)形态较为紧闭,为斜卧褶皱;晚期褶皱(轴面走向为NE-NEE向)形态较为宽缓,为直立倾伏褶皱。结合大区域褶皱构造线的分析,提出华南地区横跨型叠加褶皱的早期褶皱应为近南北向,晚期褶皱为近东西向。基于矿区内多期变形构造的交切关系、石英脉辉钼矿年龄数据以及区域相关地质事件分析,这两组褶皱构造反映了大宝山矿区乃至华南地区中生代陆内两次变形事件:NW-NNW向褶皱是印支早期华南板块内部强烈构造-岩浆活动的结果;NE-NEE向褶皱是燕山早期华南板块陆内部变形作用的结果。大宝山矿区叠加褶皱变形研究不仅为研究华南大陆叠加褶皱变形特征提供了具体例证,而且对大宝山矿区多金属矿的勘探起重要指导作用。
[Abstract]:The Dabaoshan mining area is located in the south of Nanling area. The Mesozoic Indosinian to Yanshanian period has at least two stages of folding, which clearly records its tectonic deformation history and provides a very favorable condition for understanding the tectonic evolution of the Dabaoshan mining area. Based on the analysis of fold quartz vein cleavage knee fold and other deformational structures in the mining area the superposition patterns of two generations and different directions of fold structures in the mining area are identified for the first time. It is found that the early fold (NW-NNW direction of axis strike) is closed, and the late fold (NE-NEE direction) is relatively wide and gentle, and is vertical inclined fold. Based on the analysis of large area fold tectonic lines, it is proposed that the early fold should be near S N and the late fold be near E W in South China. Based on the intersecting relationship of multi-stage deformed structures in the mining area, the age data of molybdenum quartz veins and the analysis of regional related geological events, These two sets of fold structures reflect two deformation events in the Mesozoic in the Dabaoshan mining area and even in the South China area. The result of the strong tectonic-magmatic activity in the early Indosinian South China plate is that the NE-NEE fold is the early Yanshanian South China. The result of intracontinental deformation of the plate. The study of superimposed fold deformation in Dabaoshan mining area not only provides a concrete example for studying the characteristics of superimposed fold deformation in South China continent, but also plays an important guiding role in the exploration of polymetallic ore deposits in Dabaoshan mining area.
【作者单位】：中国科学院广州地球化学研究所;中国科学院大学;
【基金】：中国地质调查局地质矿产调查评价专项(04-025-046) 国土资源部公益科研专项(201211024-03) 国家自然科学基金(41576040,40872080,41072081)资助
【分类号】：P542;P618.2

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