Development of the Geomagnetical Polarity Time Scale: A Review

Abstract

For Middle Mesozoic to Quaternary times,the geomagnetic polarity record is central to the construction of geologic time scales.The precision of the standard geomagnetical polarity time scale (GPTS) strongly influences the development of related disciplines,such as stratigraphy,paleontology,paleoclimatology and so on.We review the history of the developments in GPTS,and mainly present the recent progress in calibration of the astronomical polarity time scale (APTS),as well the shortages of the present APTS.It can be divided into three stages according to the characteristics of the GPTS development:(1) early stage,during the 1960s,is characterized by K/Ar dating and measuring the magnetization of igneous rocks,constructed the recent 5 Ma GPTS;(2) middle stage,from late 1960s to early 1990s,is characterized by analysis of marine magnetic profiles from the world′s ocean basins,constructed the integrated GPTS since Middle Mesozoic;and (3) in the last three decades,with the developments of the Milankovitch theory (astronomical climate theory) and the astronomical calculation of the Earth′s orbit,the geological time scale can be constructed by orbital tuning,which have being successfully developed as a powerful geochronometer in calibration the APTS.The precise APTS is expected to replace the CK95 GPTS and will be widely used in related disciplines.