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以秦皇岛柳江盆地新元古界为研究对象,重点研究长龙山组沉积特征、沉积相及古水流。通过野外踏勘、大比例尺剖面测量、岩层结构构造描述、交错层理及面理的测量分析,表明秦皇岛柳江盆地新元古界长龙山组发育多套粗粒石英砂岩、中粒石英砂岩、细粒石英砂岩、粉砂岩、泥岩、页岩、灰岩旋回,反映出长龙山组时期到景儿峪组时期曾发生多次海进海退事件。得到秦皇岛柳江盆地长龙山组-景儿峪组两条剖面(张岩子剖面、李庄北剖面)剖面测量结果,显示长龙山组以砂岩为主,分选较好,磨圆度较高。通过室内薄片观察,粒度分析结果显示秦皇岛柳江盆地长龙山组时期主要发育海相沉积,且底部有河流相参与,砂岩粒度主要分为海滩相及浅水陆棚相两个相带。根据层理产状玫瑰花图推断长龙山组时期古水流方向为135°左右。
Taking the Neoproterozoic in the Liujiang Basin, Qinhuangdao as the research object, the paper focuses on the sedimentary facies, sedimentary facies and paleocurrent of the Changlongshan Formation. Through field reconnaissance, large-scale profile measurement, structural description of rock strata, cross bedding and the analysis of surface texture, it shows that there are many sets of coarse quartz sandstone, medium quartz sandstone and fine grain Quartz sandstone, siltstone, mudstone, shale and limestone are cyclic. This shows that several sea-going retreats occurred during the Changlongshan Formation to the Jing’eryu Formation. The Changlongshan Formation-Jingeryu Formation two sections (Zhangyanzi section and Lizhuangbei section) of Liujiang River basin in Qinhuangdao are obtained. The results show that the Changlongshan Formation is mainly sandstone with good sorting and high degree of roundness. The results of grain size analysis showed that the sediments of Changlongshan Formation in Liujiang Basin, Qinhuangdao mainly developed marine sediments with river facies at the bottom, and the sandstone grain size was mainly divided into two facies belonged to beach facies and shallow water shelf facies. According to the bedding-like rose map, the paleo-water flow direction of the Longsonshan Formation was estimated as 135 °.