前言前寒武纪地层在地球上有广泛分布。由于已往未发现大量可靠的古生物化石,在很长一段时期内,主要限于岩石地层学方面的工作,划分、对比相当紊乱。近来,由于人们找到了大量的叠层石(Stromatolites)、核形石(Oncolithes)和微古植物(Micro-flora) 等低等生物,并在地层学上进行了较多工作,使前寒武系的划分、对比前进了一大步,尤 Preface Precambrian strata are widely distributed on Earth. Since a large number of reliable paleontological fossils have not been found in the past, the work, division and contrast of the lithostratigraphy are mainly confined for quite a long period of time. Recently, as people have found a large number of lower organisms such as Stromatolites, Oncolithes and Micro-flora, and have done more work in stratigraphy, Division of the division, compared to a big step forward, especially