摘要:
海底残留沉积约占世界陆架面积的70%[3],而残留沉积中分布最广的是残留砂.有孔虫、介形虫等微体化石,其壳体大小与砂粒相当,而不同的属种又有特定的生活环境,因此它们在沉积过程中可以反映沉积条件,在搬运作用中又可看作指相颗粒.研究残留沉积物中微体化石的属种组合、保存状况、数量和大小等特点,应能为研究陆架残留沉积的产生与变化过程提供某种依据.关于陆架残留沉积的化石资料不少,但大多局限于脊椎动物,软体动物等大化石,而对有孔虫、介形虫等微体化石群的详细情况尚缺乏分析.
Abstract:
Up to now,in literature,the paleontologic characteristics of relict sediments concern mainly macrofossils,Micropaleontolegic analysis of relict sediments in the East China Sea has revealed some distinctive features in their associated microfossils,1.unusual state of preservation, 2.low content of tests,and 3.environmental conditions reflected by the faunal assemblage is different from those of the modern environment, According to microfauna,five types of formation of relict sediments may be recognized:1.brackish-water nearshor area,2,shell beach,3.estuaries,4. littoral marsh,and 5.continental environments.
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