The allochthonous genesis model about the extra-thick and high-quality coalbed in Xianfeng basin, Yunnan Province, China

Abstract

An extra-thick high-quality brown coal was found to have accumulated in the Xianfeng basin in Yunnan Province, China. There are also abundant sedimentary marks of allochthonous genesis in the extra-thick coalbeds. These genesis indicators reveal a new submodel about allochthonous accumulation, which is: the long-distance river transportation of detrital plant and inorganic matter!?the sedimentation of detrital plant fan delta+the hypautochthony accumulation of local lakeshore swamp peat!?the autochthonous accumulation of local lacustrine peat+the sedimentation of fine inorganic matter!?the mixing and transportation by flood current or weak storm flow or underwater gravity flow!?the mechanical differentiation and their resedimentation between detrital plant and inorganic matter. This submodel can be called the double accumulation of lacustrine detrital plant fan delta and underwater gravity flow  or Xianfeng submodel , which supplements the allochthonous-hypautochthony lacustrine combination accumulation model  of the extrathick coalbeds. The combination accumulation model is based on the Fuxin submodel and Fushun submodel in the Chinese Mesozoic and Cenozoic intarcontinental fault basin.