豫西济源谭庄组河流沉积特征

豫西济源晚三叠世谭庄组下段为河流体系沉积，其河近沉积可分出块状含砾砂岩相（Ｃ＿ｘ）、平行层理砂岩相（Ｓ＿ｈ）、块状砂岩相（Ｓ＿ｍ）、板状交错层理砂岩相（Ｓ＿ｐ）、槽状交错层理砂岩相（Ｓ＿ｔ）及波纹层理砂岩相（Ｓ＿ｒ）；河道间沉积可分出土黄色泥岩相（相１）、灰色泥岩夹煤线相（２）、透镜状砂岩相（相３）与薄层粉砂岩相（相４）．据纵向相组合特征，可识别出高弯度（曲流）河流沉积体系与低弯度暂时往河流沉积体系两种类型，气候条件对河流类型及河流沉积作用过程起重要控制作用。

The fluvial Sedimentary Features of Tanzhuang Formation in Jiyuan, westen Henan

The lower section of Tanzhuang Formation in late Triassic in Jiyuan, Western Henan, is interpreted as fluvial deposits.The channei deposits of the fluvial depositional system can be divided into massive gravel-bearing sandstone facies(C_m)sandstone facies(S_h),massive bedding sandstone facles(S_m), planar cross-bedding sandstone facies(S_p),trough cross-bedding sandstore facies(S_t)and riple bdding sandstne facies; The fluvial piane deposite can be divided into yellow mud facies (facies 1),grey mud facies with very thin coal bed(facies 2),lenticular sandstore facies(facies 3)and thin siltstone facies (facies 4).Two types of fluvial depositional system are identified according to the facies scquence in the sectlon One is high sinuosity fluvial depositional system, and another is low sinuosity tempora-ry fluvial depositional system .The decisive factor which controls the type and depositionai pro-cess of the fluvial depositional system is the climate condition during that time。