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How did Jurassic rifting help begin the formation of the Atlantic Ocean and Gulf of Mexico?

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Jurassic paleogeography — Jurassic Period Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the late Jurassic Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.

During the Jurassic Period, the fragmentation of the supercontinent Pangea progressed as North America began pulling away from Eurasia and Gondwana. This continental rifting created linear troughs along the continental margins where thick sequences of sediments accumulated.1

As these rifts widened, oceanic spreading centers formed, initiating the development of new ocean basins. In the early stages of the Atlantic’s formation, these basins were restricted, leading to the accumulation of nonmarine sediments and, in areas like the Gulf of Mexico, significant marginal marine deposits such as evaporites (salt). These salt deposits, which formed through prolonged seawater evaporation, are characteristic of the Gulf Coast region's Jurassic geologic history. As the basins continued to grow and connect with the open ocean, they eventually filled with marine waters, facilitating the deposition of organic-rich shales due to restricted circulation. This tectonic activity was fundamental to the structural evolution of the Atlantic basin and the Gulf of Mexico.213