Insights on Formation of the Gulf of Mexico by Rayleigh Surface Wave Imaging

Abstract

Introduction Geographic SettingPassive margins mark the region where the lithospheric plates break apart and the transition from continental to an oceanic domain takes place. This geologic region preserves a record of the tectonic, magmatic, and sedimentary processes that accompany continental extension and therefore is important to the understanding of plate tectonics. In this study, we investigated the margins surrounding the Gulf of Mexico (GOM), as well as the deep GOM ocean itself, to better understand the Triassic-Jurassic breakup of the North and South American plates during the opening of the Atlantic. The GOM is a relatively small ocean basin situated south of the continental US that is surrounded on the east, north, and west by the North American plate, and on the south by Cuba. The GOM is connected to the Atlantic Ocean through the Florida Straits and to the Caribbean Sea through the Yucatan Channel (Figure 1). A large part of the GOM is occupied by continental margins made up of stretched continental lithosphere with a small ocean basin in the center. The US Gulf Coast margin and the margin offshore Yucatan formed as a conjugate pair during a period of rifting beginning in Late Triassic (∼200 Ma) followed by seafloor spreading starting and ceasing between ∼160 and ∼140 Ma (