定年的非生物地层学方法

将目前见诸报道的各种非生物地层学定年方法(未包括主要针对年轻沉积物和岩浆岩体的方法) 概括为6类, 从基本原理、具体方法、适用条件、应用实例等多方面对每种方法进行了评述。磁性地层学方法、米兰柯维奇旋回法和锶同位素地层学方法的共同优势在于其测年的全球等时性和可对比性, 但它们都属间接测年。宇宙尘埃元素法优势在于对沉积间断时间的确定。裂变径迹法与放射性同位素法的优点能对地层绝对年龄进行直接估测, 但对样品类型及保存程度要求较苛刻。综合印证、学科交叉、全方位开发和提取沉积记录中蕴涵的各类年代学信息, 是地层定年应用和研究中应遵循的原则。

Non-Biostratigraphical Methods for Dating

Dating of the absolute ages of strata is one of the fundamental topics in the field of geology.All kinds of non-biostratigraphical methods for dating(not including the methods for young sediments and magmatic rock herein) reported at the present time are summarized as 6 categories.Their basic theories,operating processes,working conditions and successful cases and so on are commented one by one.The common advantages of dating methods based on magnetostratigraphy,Milankovitch cycles and Strontium isotope are global correlativeness and isochronism,but they all belong to indirect dating methods.The merit of methods based on cosmic dust elements is to determine the interrupted interval of sedimentation.The common advantage of methods based on fission track or radioactive isotopes is to directly estimate the absolute ages of strata,but rigorous limits on sample type and conservation degree are required at the same time.The principle that we should follow with regard to strata dating is integrated verifying,multi-discipline intercrossing,all-directionally developing and extracting the information contained in strata.