第3章 地层学Stratigraphy 3.1 概念、定律和地层的接触关系3.1 Concepts,laws & contact relationships of strata3.2 地层划分和对比3.2 Stratigraphic subdivision and correlation 3.3 地层单位和地质年代3.3 Stratigraphic units and geological times 3.4 地层的形成作用3.4 Stratigraphic formation3.2.1 Concepts of Stratigraphic subdivision and correlation地层划分：根据地层的特征和属性（如岩性、化石和不整合面等）将地层组织成相应的单位。Stratigraphic subdivision: The systematic organization of the Earths rock bodies, as they are found in their original relationships, into units based on any of
