Gulf of Mexico basin

The formation of the Gulf of Mexico, an oceanic rift basin located between North America and the Yucatan Block, was preceded by the breakup of the Supercontinent Pangaea in the Late-Triassic, weakening the lithosphere.

Rifting between the North and South American plates continued in the Early-Jurassic, approximately 160 million years ago, and formation of the Gulf of Mexico, including subsidence due to crustal thinning, was complete by 140 Ma.

[2] Beneath the sediments of the Gulf of Mexico basin, most of the pre-Triassic basement rocks are believed to be allochthonous thrust sheets sutured during the formation of Pangaea.

[1][2] In addition to the basalt flows, other important igneous rock types include diabases associated with the grabens and red beds, and overlapping, north-northwest trending dike swarms related to the tectonic volcanism of the breakup of Pangaea.

[4] As mentioned above, the pre-rift stratigraphy of the central Gulf of Mexico basin, which now lies beneath nearly 20 kilometers of sediment deposited during the Jurassic through the Holocene, is made up primarily of extensional graben formations filled with "red beds," basalt flows, and diabase dikes and sills deposited and intruded during the break-up of Pangaea and the explosion of the Central Atlantic Magmatic Plume.

The Gulf of Mexico basin red beds are specifically named the Eagle Mills formation, located directly beneath the salt, evaporate, and marine sediments deposited during the Jurassic, and often found with the diabase dikes and basalt flows mentioned above.

[6] Basement rocks in the northeastern region of the Gulf of Mexico basin are fragments of the African Plate, which remained behind during the breakup of Pangaea and date back to the late Precambrian through the Cambrian.

[8][12] The salt structures, which include anticlines, pillows, plugs and walls, in addition to extensive sheets, were created long after deposition by the rapid overlying sedimentation.