Magnetic Anomalies Indicate Gulf of Mexico Originated by Counterclockwise Rotation of Yucatan from Gulf Coast: ABSTRACT

Abstract

Although the Gulf of Mexico is much studied, little is as yet known about the basement underlying its huge thicknesses of Mesozoic and Cenozoic sediment. They suggest that oceanic crust occupies the central gulf and is surrounded by a broad zone of transitional material because they recognize linear magnetic anomalies that are attributable to sea-floor spreading about a pole near 27/sup 0/N, 78/sup 0/W, for a period of roughly 8 m.y. close to the time of the Jurassic-Cretaceous boundary. This interpretation is compatible with several models based upon geologic evidence involving the counterclockwise rotation of Yucatan away from the northern Gulf Coast. Because of low amplitudes and the small number of anomalies observed, this cannot be a very strong attribution, but closely spaced, high-resolution magnetic surveys particularly in the southwestern gulf would go far toward testing the validity of their interpretation.