This Study will conduct a marine geophysical, geological, geochemical, and chronological investigation of 19 seamounts in the Magellan, Marshall, and Wake provinces in the western Pacific ocean. The goal is to document the Cretaceous Expression of the South Pacific Isotopic and Thermal Anomaly. Laser fusion 40Sr/39Ar dating will provide the age control on the samples. Radiogenic isotope geochemistry of mineral Separates of phenocrysts will be used to avoid seawater alteration effects. Gravity data will be inverted with respect to elastic thickness of the lithosphere and magnetic surveys will serve to determine the magnetic paleopoles. Thus this work will provide constraints on the Cretaceous extent of South Pacific Isotopic and Thermal Anamaly on Pacific plate motion prior to 100 Ma, constraints on the Cretaceous apparent polar wander path, and identification of potential hotspot chains.
