Plate Rotation of the Northern Antarctic Peninsula Since the Late Cretaceous: Implications for the Tectonic Evolution of the Scotia Sea Region

Abstract

AbstractPlate reconstructions provide basic constraints on the tectonic evolution of the Antarctic Peninsula but they are limited by a scarcity of paleomagnetic data. Here, using a combination of new and published paleomagnetic data and geological evidence, we present an updated reconstruction of the plate rotation and spatio‐temporal history of magmatism of the northern Antarctic Peninsula since ∼90 Ma. The Phoenix Plate‐Antarctic Peninsula convergence variation and back‐arc extension of the Scotia Plate are correlated to five distinct plate rotation periods. The initiation of the ancestral South Sandwich subduction zone and the late Paleocene separation between the Antarctic Peninsula and South America may be explained by the small‐ and large‐scale clockwise rotation of the Antarctic Peninsula starting at ∼80 and 62 Ma, respectively. Furthermore, we have identified five pulses of magmatism, which are correlated to the Phoenix Plate‐Antarctic Peninsula convergence rates. The Antarctic Peninsula plate rotation fits well with the process observed in the Phoenix Plate subduction, long‐term variation of the magmatism and tectonic evolution in the Scotia Sea, clarifying the relationship between these geological events.