江浙一带现代海滩的生物扰动构造及其指相意义

底栖生物在沉积物表面及其内部留下的各种活动痕迹——生物扰动构造(Bioturbation)具有指示环境的重要意义,这是由于底栖生物的生存和发展与沉积物的性质和沉积作用过程休戚相关,对沉积环境有极大的依赖性。同时,生物又通过其自身的觅食和摄食活动,反过来影响沉积作用过程,并可破坏和改造沉积物的原生构造。因此,这种原地生成的生物扰动构造如能保存在地层中,它们就可以为沉积环境的判别提供可靠的信息。

BIOTURBATION STRUCTURES OF MODERN BEACH SEDIMENTS AND THEIR SIGNIFICANCE IN DETERMINING OF SEDIMENTARY ENVIRONMENTS IN JIANGSU AND ZHEJIANG PROVINCES

In light of the recent study of bioturbation in the coast areas of Jiangsu-Zhejiang, it has been shown that the burrow forms of benthos are related to water depths. Most of shallow benthos tend to live in various vertical burrows in order to avoid or reduce the influences of changeable environmental variables. The intensity of bioturbation is obviously different and closely related to the rates of sedimentation. In general, the lower the rate of sedimentation the more intensive the bioturbation.In addition, the bioturbation can affect directly the microchemical environment near the interface between water and sediment and even changes the extension of oxidation zone within sediments. Perhaps, it not only influences the determination of ancient redox environment, but also shows indirectly some critical environmental factors.