江西萍乐凹陷构造-沉积演化的基本特征及对找煤预测的启示  

Tectonic-Sedimentary Characteristics of the Ping(Pingxiang)-Le(Leping) Depression in Jiangxi Province and its Implications on Coal Mineral Resource Prospecting

作　　者：许德如[1] 王力[1,2] 王智琳[1,2] 吴俊[1,2] 吴传军[1,3] 

机构地区：[1]中国科学院广州地球化学研究所矿物学与成矿学重点实验室,广东广州510640 [2]中国科学院研究生院,北京100049 [3]中国科技大学地球和空间科学学院,安徽合肥230026

出　　处：《大地构造与成矿学》2011年第4期513-524,共12页Geotectonica et Metallogenia

基　　金：全国危机矿山接替资源找矿项目(项目编码200736030)资助

摘　　要：中新生代以来,江西萍乐(萍乡-乐平)凹陷带的构造-沉积演化经历了三期四个阶段,即:印支期大规模的推覆、燕山早期晚三叠世末的基底拆离和褶皱-逆冲以及早侏罗世末的盖层滑脱、喜山期新近纪盖层和基底的滑覆,反映盆地性质具有断(裂)陷与坳陷的多次转换特征。构造运动对煤层的控制也表现为坳陷导致煤系地层盖层加厚、埋藏加深及错断、重复,以及由断陷导致的煤系地层地堑式错断、不连续或埋藏加深。位于萍乐凹陷中段的丰城地区,因远离凹陷带南缘的武功山和北缘的九岭两个巨型隆起带,储煤构造相对简单,晚二叠世龙潭组煤系地层受推覆构造作用影响较小,B4煤层保存条件较好,是有利的储煤区块。据此,建立了丰城地区构造控煤模式。The formation of the Ping（Pingxiang）-Le（Leping） coal-bearing depression zone was strictly controlled by three-period and four-stages of tectonic-sedimentary evolution from Mesozoic to Cenozoic.These include Nappe-stage in Indosinian,basal-detachment and fold-thrust stage in the end of the Late Triassic and cover strike-slip stage in the end of the Early Jurassic,and cover and basal sliding stage during Himalayan.Thus,multistage conversion between sag and fault depression made the basin type of the Pingle depression showing different geotectonic features.And different geotectonic features lead to diverse occurrence features of the coal seam.Sag led to thicker cover strata,greater depth of coal seams,stratigraphic leap and repetition;while fault depression led to stratigraphic leap,discontinuity or the greater buried depth like graben.The Fengcheng region is favorable location for coal mine as is it located in the middle of the Pingle depression and far away from the southern Wugongshan and the northern Jiuling uplift of the Pingle depression,its structural styles are relatively simple and the B4 coal stratum was well preserved.As a result of this study,we establish a coal-controlling structural model which could be a guide for coal mine exploration in the Fengcheng region.

关 键 词：萍乐凹陷 构造演化 推覆构造 找煤预测 

分 类 号：P542[天文地球—构造地质学] P612[天文地球—地质学]