黄河三角洲的冰融沉积构造及其研究意义

冰成沉积构造是在冰直接控制下而形成的沉积构造，冰融沉积构造是其中的一类。通过对黄河三角洲的野外地质考察，发现并描述了7种冰融沉积构造：冰融水流痕、冰成裂流痕、冰融丘(冰融痕)、冰成泥沙片、冰成泥沙笋、冰成豆粒和冰成根状构造。冰融沉积构定的指示意义。最后，系统总结了冰成沉积构造的分类。

ICE-MOLTEN SEDIMENTARY STRUCTURE AND ITS IMPORTANCE IN THE YELLOW RIVER DELTA

Ice-molten sedimentary structure is a kind of ice-induced sedimentary structure controlled mainly by ice. Ice-molten sedimentary structures produced in not only glacial zone and permafrost but also seasonal frozen zone. Through field observations, seven ice-molten sedimentary structures, i.e. ice-molten water flow mark, ice-induced rip current mark, ice-molten dome (mark), ice-induced silt or mud slices, ice-induced mud-sand stalagmite, ice-induced pisolite, ice-induced rhizome, are recognized in the Yellow River delta and described in this paper. Totally, ice-molten sedimentary structures formed under condition of low temperature, fresh sediments saturated with water. An analysis by synthesis about the characters of modern ice-molten sedimentary structures and ancient ice-molten sedimentary structures in Maershan Member, Laiyang Formation in the Jiaolai basin, east China, shows that ice-molten sedimentary structures are important for the identification of sedimentary environments such as river channel,delta and tidal flat, and low temperature climate. Additionally, systematical classification on ice-formed sedimentary structures is made, and the relationship on characters of ice-formed sedimentary structures between permafrost zone and seasonal frozen zone is discussed in this paper. Though scales and species of ice-formed sedimentary structures produced from permafrost zone and seasonal frozen zone are great different, their mechanisms of formation are basically similar.