APPLYING CYCLE-SCALED MAGNETOSTRATIGRAPHY FOR GLOBAL CORRELATION OF SELECTED MAJOR PALEOCLIMATIC EVENTS IN THE TRIASSIC, CRETACEOUS AND QUATERNARY

Reversals of the Earth’s magnetic field are recorded by preferential orientation of iron oxide grains during their deposition in all types of sediments. When combined with cyclostratigraphy, magnetostratigraphy has proved to be one of the robust ways to build portions of the geologic timescale and to enable global correlation among various settings. For this PhD program, Yang Zhang utilized the combination of magnetic polarity scales with astronomical-cycle tuning to resolve long-debating time scaling of time intervals where major climate shifts (e.g., major excursions in Earth’s carbon cycle reflected in isotopic anomalies) took place. Other stratigraphical tools such as geochemistry data, radiometric dating, and biostratigraphy help constrain the validity and accuracy of cycle-scaled magnetic polarity scales.