陆相断陷盆地超厚煤层异地堆积的新模式  

New Evidence and New Model about Allochthonous Accumulation of Extra-Thick Coalbeds in Continental Fault Basin, China

作　　者：吴冲龙[1] 李绍虎[1] 王根发[1] 罗映娟[1] 

机构地区：[1]中国地质大学资源学院,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2003年第3期289-296,共8页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目 (No .495 72 12 8) .

摘　　要：在云南先锋盆地和小龙潭盆地的超厚煤层中 ,有丰富的异地成因的沉积学标志 .这些成因标志揭示了 2种新的异地堆积亚模式 ,即“先锋亚模式”和“小龙潭亚模式” .其中 ,“先锋亚模式”可归纳为“湖相植物碎屑扇三角洲 -水下重力流二次堆积” ;“小龙潭亚模式”可归纳为“湖相植物碎屑三角洲 -水下重力流二次堆积” .综合这 2种亚模式及笔者原先所建立的“阜新亚模式”和“抚顺亚模式” ,可以进一步概括出完整的中国中、新生代内陆断陷盆地超厚煤层的“异地 -微异地二次湖泊复合堆积模式” ,即“腐植型植物碎屑河流远源搬运→植物碎屑扇三角洲或植物碎屑三角洲沉积 +湖泊漂浮异地植物碎屑沉积 +湖滨沼泽泥炭微异地堆积 +湖泊原地藻类泥炭原地堆积 +泥质碎屑或砂质碎屑或生物壳屑沉积→洪水、弱风暴流或水下重力流的混合和搬运作用→植物碎屑与无机碎屑的机械分异和再沉积” .Abundant sedimentary marks of allochthonous genesis are present in the extra-thick coalbeds both in Xianfeng basin and in Xiaolongtan basin in Yunnan. These genesis indicators reveal two new submodels about allochthonous accumulation: Xianfeng submodel and Xiaolongtan submodel. Xianfeng submodel can be reduced to the twice accumulation of lacustrine peaty fan delta and underwater gravity flow, and Xiaolongtan submodel can be reduced to the twice accumulation of lacustrine peaty delta and underwater gravity flow. Integrating these two submodels with Fuxin submodel and Fushun submodel previously established by the authors of this paper, a complete allochthonous-hypautochthony twice lacustrine combination accumulation model for the extra-thick coalbeds in Chinese Mesozoic and Cenozoic intracontinental fault basin is thus established, as shown below: the river distant transport of humic-peat detritus → the sedimentation of peaty fan delta or peaty delta + the allochthonous sedimentation of lacustrine drift peat + the hypautochthony accumulation of local lakeshore swamp peat + the autochthonous accumulation of local lacustrine algae peat + the sedimentation fine detritus, medium-macro-grained detritus or biostromal shelly detritus → the mix and transportation because of flood current or weak storm flow or underwater gravity flow → the mechanical differentiation and resedimentation of peat and inorganic detritus.

关 键 词：陆相断陷盆地 超厚煤层 云南 先锋盆地 沉积学标志 异地堆积亚模式 小龙潭盆地 新生代 聚煤模式 中生代 

分 类 号：P618.11[天文地球—矿床学]