Paleomagnetism, magnetostratigraphy

Abstract

Magnetic stratigraphy is now one of the principal tools that allow the precise, high-resolution correlation of geologic events in the stratigraphic record, especially climatic events. It is unique among stratigraphic methods in that global high-resolution correlations are possible between terrestrial and marine records, and does not suffer from issues of local facies changes or limited lateral extent of most other stratigraphic markers. Of course, the researcher must be aware of the limitations: relatively complete well-exposed sections of fine-grained rocks are required, as is an independent form of time control to allow calibration. Every sample must be carefully analyzed by multiple techniques to insure that the primary or characteristic remanence has been recovered and overprinting removed. Nonetheless, magnetic stratigraphy has improved our correlations of global events by several orders of magnitude, and corrected many erroneous correlations that were once widely accepted. It has allowed for many other interesting studies, such as analysis of rates of sedimentation, and tests of the isochroneity of biostratigraphic events. In short, the horizon is limitless for the application of paleomagnetism to stratified rocks.