Chronostratigraphic Methods Using Global Time Markers

Several widely applied chronostratigraphic dating methods are based on globally distributed strata that contain physical or chemical anomalies, climatic rhythms or seasonal cycles resulting from global events (Walliser 1983/1984). To yield time marks, these globally present anomalies or stratigraphic records must be very accurately dated by suitable methods. Paleomagnetic remanence in magmatic rocks and sediments (Sect. 7.1) recording changes in the Earth’s magnetic field is an example of time markers. Variations in the stable oxygen isotope ratio in planktonic foraminiferal tests from pelagic sediments caused by variations in climate (Sect. 7.2) are another example of a natural stratigraphic record.