龙永煤田隐伏区找煤前景分析

龙永煤田暴露区找煤基本勘查完毕,隐伏区找煤成为今后工作的主攻方向。根据区内地层及构造特征,结合找煤实例分析,认为：①区内地表出露翠屏山组中下部地层的区块以及三叠系下统溪口组与翠屏山组中下部直接接触的区块,由于层间滑脱断层缺失上部地层,使煤系地层埋藏变浅,是找煤的有利范围;②层间逆冲推覆构造主要分布在煤田东部,造成童子岩组的地层重复,由于上盘构造复杂,含煤性变差失去勘查价值,下盘煤系地层保存完整,煤炭资源量可观,其下盘可作为找煤的主要方向;③煤田东部红林坪-白沙-茶林盂一带出露白垩系沙县组（即红层）．如“红层”与下伏地层为小角度不整合接触,则其“红层”与下伏的童子岩组及翠屏山组接触地带为找煤的有利区块;④区内“火山岩”主要分布在东北部,因厚度大,煤系地层埋藏深,找煤难度较大;⑤基底逆冲推覆构造在区内发育规模较小．煤田内出露的“老地层”基本上为基底隆起．其下找煤的可能性较小。

Coal Looking Prospect Analysis in Concealed Area in Longyong Coalfield

Coal looking in exposed area in the Longyong coalfield is basically finished, thus coal looking in concealed area becomes the main thrust from now on. According to the area＇s strata and structural features, combined with coal looking ease studies considered that： （1） middle and lower part block of surface exposed Cuipingshan Formation and thereto directly contacted block of Lower Triassic Xikou Formation absence of upper part strata owing to decollement fault, make coal measures strata shallower buried, thus favorable to coal looking; （2） interlayer ramping nappe structures mainly distributed in eastern coalfield, make the repetition of Tongziyan Formation strata, the upper plate structurally complex, coal-hearing property poor, thus no value of further exploration, while the lower plate coal measures strata perfectly preserved with sizable coal resources, thus can be focus direction of coal looking; （3） Cretaceous Shaxian Formation （red beds） outcropped in Honglinping-Baisha-Chalinyu region in eastern part of the coalfield, if it is small angular unconformity contacted underlying strata, then the ＂red beds＂ and Tongziyan Formation, Cuipingshan Formation contact region is favorable for coal looking; （4） volcanic rock is mainly distributed in the northeastern part, because of its large thickness, coal measures will be buried deeply and adverse to coal looking; （5） basement ramping nappe structures are small sized in the area, outcropped ＂old strata＂ are basically basement uplift, coal looking is on the off chance.