摘要:
近河口处的潮间分流河道充填沉积速率较高,但仍有海产双壳类Cyclina Sinensis(Gmelin)等生活在那里,伴随堆积而向上逃逸,其逃跑遗迹长可达40cm之多.根据沉积速率,可将软体动物扰动分为三种基本类型,即潮坪型、分流河口型和独流河口型.黄河分流河道的边滩上长有phragmites CommunisTrin和Polygonum hydropipe L.,在丰水期,堆积相对缓慢时,植物在接近地表处长出新的根系而取代堆积较快时被埋藏的根系,由此维持着生命的延续,其逃逸迹可达0.9—1.2m长.
Abstract:
Some Mollusks such as Cyclina sinensis (Gmelin) could live in the distributary channel deposits very close to Yellow River mouth, although the sedimentary rate is high there. The escape traces can over 40cm long, accompaning with the thichening deposition. Following results were presented in the paper. 1. Distribution of mollusks in the Huanghe Horbour's intertidal zone: Above the mean high tidal line was Glaucomya chinsis ( Gray) zone. Under the mean high tidal line was Aloidis laevis- Cyclina sinensis-Sinonovacula zone. Glaucomya chinensis (Gray) was considered to be of greater significant for analying Huanghe River delta's fades. 2.Bioturbation models of Mollusks: There are three main types: tidal flat, distributary mouth and single river mouth.The tidal flat type may be a characteristic bed for us to divide defferent Yellow River delta lobes. 3. Sedimentary rate is the main factor that affect the Mollusks' living. The stage of deposition, such as season, could be shown through study bio-escape sedimentary structure. The plants, Phragmites communis Trin.and Polygonum hydropiper L., can live in lateral bar deposits of the active Yellow River distributary channel. During the flood season in 1988, the stems of these plants were partly buried by silt, but sprouted new roots and revived when sedimentary rate decreased. The longths of these plants escape traces can as long as 90-120cm.
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