| dc.description.abstract | This thesis presents a comprehensive exploration of Mesozoic Oceanic Plate Stratigraphy (OPS) within accreted orogenic belts, with a specific focus on identifying and compiling Mid-Ocean Ridge Basalts (MORB) and Ocean Island Basalts (OIB) to reconstruct subducted hotspot tracks. The study encompasses diverse geological locales, especially in the Circum Pacific, including Japan, Russia, the Philippines, Costa Rica, Mexico, California, Alaska, and New Zealand, leveraging extensive geological data to unravel the historical trajectory of ancient Pacific Plates. The research primarily centers on elucidating the geological history of ancient oceanic remnants associated with the Izanagi Plate, Farallon Plates, and Phoenix Plates, emphasizing the geochemical affinity of the volcanic features and the ages of oceanic floor and seamount birth. The study reveals that ocean floor and seamounts accreted from the Late Carboniferous to the Late Cretaceous in various geological timeframes. A key contribution of this research lies in refining the early formation of the Pacific Plate, drawing on geochronological affinity and volcanic feature ages within the OPS Sequence. These findings offer a nuanced perspective, potentially revising previous estimations and enriching our comprehension of early plate tectonics.
Furthermore, the study identifies a slight predominance of Mesozoic hotspot distribution in the southern hemisphere, aligning with the contemporary configuration of the Pacific Plate. The research underscores the importance of further analyses, including dating ages, paleomagnetic studies, and geochemical assessments of selected volcanic features. These endeavors are pivotal in advancing our understanding of plate tectonics and the evolution of the Pacific Plate, ultimately contributing to a more accurate portrayal of Earth's dynamic geological history. | |
