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地质矿产部海洋地质研究所最近在黄河口地区的海岸带调查中发现数条古贝壳堤.长数十公里,宽数百米,厚度较大,十分稳定,埋藏较浅.这些古贝壳堤沿西北走向进入河北省境内,并可能与歧口贝壳堤、巨葛庄贝壳堤、天津育婴堂贝壳堤相连.贝壳堤具向上变细的层序,发育冲洗交错层理和风暴层理.向海一侧陡,向陆一侧缓.其展布方向明显地受风浪和潮流控制.在贝壳堤的向陆一方往往伴随有发育较差的泻湖和滨后沼泽.组成贝壳堤的贝类主要有石蛤、金蛤、文蛤、日本镜蛤、米蛤、锥螺、蛏、牡蛎等.以贝壳碎屑为主.贝壳堤中含少量砂,以石英为主,分选好,磨圆程度甚高,在石英砂中磁铁矿含量较高,显然古贝壳堤是高能环境的产物.从地层层序上看,古贝壳堤以及现在沿低潮线正在发育的贝壳堤,均盖在三角洲河流沉积之上,所以从广意上说,它是海进过程的产物,是相对稳定一轻微蚀退海岸的低潮线的标志.古贝壳堤又往往为沼泽和泻湖相沉积所覆盖.其上为三角洲平原相的河流和分流问沉积.表现了一个完整的海退层序.
Recently, the Institute of Marine Geology of the Ministry of Geology and Mineral Resources discovered a number of ancient shell embankments in the coastal survey of the Yellow River estuary area, covering tens of kilometers in length and hundreds of meters in width with high stability and shallow burying. Northwest into Hebei Province, and may be connected with the Qikou shell embankment, Jugezhuang shell embankment, Tianjin Yuyintang shell embankment connected upwardly thinning of the shell sequence, the development of cross-stratified stratum and storm bedding. Side steep, slow to the side of the land.The direction of its distribution was significantly affected by the storm surge and tidal current.In the shell side of the embankment to the land is often accompanied by poor lagoon and the development of the marsh.Composed shell shell dike shellfish are mainly stone Clams, clams, clams, Japanese mirror clams, rice clams, cones, jackals, oysters, etc .. Shell shell embankment containing a small amount of sand, mainly quartz, sorting well, a very high degree of rounding , With high magnetite content in quartz sand, it is clear that the ancient shell dike is a product of a high-energy environment.From the stratigraphic sequence, the ancient shell dike and the now developing shell dike along the low tide line are all covered by deltaic river sediments Therefore, broadly speaking, it is the product of the sea-going process and is The stability of a slight mark and erosion low tide line the coast of the ancient shell dike is often swamp and lagoon facies covered by its upper delta plain with rivers and diversion ask deposition. Show a complete sequence regression.