前言在迭层石学的学科分枝上至少有五个方面:生物地层学、沉积学、生物学、地球物理学以及形态测量学。这些方面都不是互相孤立的,但它们在研究目的、所用概念和使用的独立命名上所强调的方面是不同的。一种人,是“生物地层工作者”(“biostratigraphers”),它们的主要任务,是根螺化石迭层石组合的详细研究,并结合它们上下地层的放射性年令测定,进行地层划分 Preface There are at least five aspects in the subject branch of the petrology: biostratigraphy, sedimentology, biology, geophysics and morphometry. None of these aspects are isolated from each other, but they differ in their research objectives, the concepts used and the independent naming of the use. One type of person, “biostratigraphers,” whose main task is the detailed study of the combination of the genus Heliconia and the dating of the upper and lower strata by radioactivity, stratigraphic division