内蒙古桌子山中奥陶统拉什仲组深水水道沉积  

Submarine Channel Complex Deposits of the Middle Ordovician Lashizhong Formation in Zhuozishan Area,Inner Mongolia

作　　者：肖彬[1] 何幼斌[1] 罗进雄[1] 苑伯超[1] 

机构地区：[1]长江大学地球科学学院,武汉430100

出　　处：《地质论评》2014年第2期321-331,共11页Geological Review

基　　金：国家自然科学基金资助项目(编号41072086);高等学校博士学科点专项基金资助项目(编号20104220110002)的部分成果

摘　　要：内蒙古桌子山中奥陶统拉什仲组发育一套典型的浊流沉积。通过详细的野外观察和室内岩石薄片鉴定,分析了拉什仲组的岩石类型及其组合关系,划分出5种岩相类型及3个深水水道复合体。在此基础上,综合分析了拉什仲组水道复合体沉积特征,建立了拉什仲组深水水道沉积模式。研究表明,下部水道复合体砂岩具有向上变细变薄的特征,水道侧向迁移加积趋势明显,可能位于深水水道的弯曲带;而中部及上部水道复合体水道砂体侧向延伸稳定,二者上部均为一套粉砂岩、页岩薄互层沉积,水道复合体以垂向加积作用为主,可能发育于水道末端。Turbidity current deposits of the middle Ordovician Lashizhong Formation well developed in Zhuozishan Area. Based on field work and thin section analysis, the lithotypes and its relationship have been studied, and five lithofacies and three submarine channel complex deposits have been identified. According to integrated analysis on sedimentary characteristics of channel complex deposits, a depositional model for the submarine channels of Lashizhong Formation is proposed. The study indicates that the lower submarine channel complex deposits mainly consisted of sandstones with fining and thinning upwards stacking patterns, resulting from obvious lateral migration and vertical aggradation of the channel complex, which probably located at the region of sinuous submarine channel;The middle and upper channel complexes consist of sandstones extending stably on the lateral side, both with the thin alternating layers of siltstones and shales in the upper part, resulting from vertical aggradation of the channel complex, which probably located at the terminus of channels.

关 键 词：深水水道沉积 水道复合体 中奥陶统 拉什仲组 桌子山 

分 类 号：P512.2[天文地球—地质学]