Chemostratigraphy, Magnetostratigraphy, Chronology, Palaeoenvironments and Correlations. Overview

Abstract

The tools of stable isotopes, natural radioactivity, radio-isotopes, paleomagnetic directions, magnetic susceptibility, chemical ratios, and other laboratory or physical-chemical logging methods can detect paleoenvironmental events and provide precise age-control calibrations that not always obvious from visual inspection of the sedimentary and paleontological records. When combined with cycle stratigraphy and other sedimentary features, one obtains fascinating insights into Earth’s history. Two examples are the discovery of a pronounced mid-Valanginian (early Cretaceous) cooling event and the realization that the “100-kyr cycles” of late Pleistocene glaciations are partially an artifact of averaging of doublet and triplet “40-kyr” obliquity-driven glacial cycles. Keywords:Carbon, Oxygen, Paleomagnetism, isotopes, Cretaceous, Valanginian, Weissert excursion, Quaternary, Pleistocene, paleoclimate, cycles, glaciation