Structure, age, and tectonic evolution of the Gulf of Mexico

Andreína García-Reyes (1) , Jérôme Dyment (1)

1 IPGP (UMR_7154) - Institut de Physique du Globe de Paris

The Gulf of Mexico is an isolated oceanic basin whose nature, structure and age are not fully elucidated, mostly because seafloor spreading isochrons have not been identified in this basin so far. We compiled and processed all publicly available marine magnetic data to produce a new magnetic anomaly map of the Gulf of Mexico. This map reveals a fan-like set of intermediate-wavelength (>100 km) magnetic anomalies related to seafloor spreading. Our magnetic anomaly-based plate reconstructions (1) support a counterclockwise rotation of the Yucatán Block around a pole located NW of Cuba, (2) accommodate the fracture zone trends depicted by the gravity data, and (3) suggest that the Continent-Ocean Boundary lies immediately south of the Houston magnetic anomaly, close to the shoreline, implying that oceanic crust underlies a significant part of the Sigsbee salt province. Our attempt to identify the intermediate wavelength anomalies by comparison with filtered Geomagnetic Polarity Time Scales dates the onset of seafloor spreading before the Tithonian (>150 Ma) and its cessation at the Berriasian (140 Ma).

Domains: Sciences of the Universe [physics]

Andreína García-Reyes, Jérôme Dyment. Structure, age, and tectonic evolution of the Gulf of Mexico. Earth and Planetary Science Letters, 2022, 577, pp.117259. ⟨10.1016/j.epsl.2021.117259⟩. ⟨insu-03452882⟩