Gulf Coast of the United States Pensacola, St. Petersburg, Tampa, and increasingly, Sarasota. All are the centers of their respective metropolitan areas and contain large ports. (Baton Rouge is relatively far from the Gulf of Mexico; its port is on the Mississippi River, as is the port of New Orleans.) The Gulf Coast is made of many inlets, bays, and lagoons. The coast is also intersected by numerous rivers, the largest of which is the Mississippi River. Much of the land along the Gulf Coast is, or was, marshland. Ringing the Gulf Coast is the Gulf Coastal Plain which reaches from Southern Texas to the western
Gulf of Mexico the present Gulf of Mexico basin originated in Late Triassic time as the result of rifting within Pangea. The rifting was associated with zones of weakness within Pangea, including sutures where the Laurentia, South American, and African plates collided to create it. First, there was a Late Triassic-Early Jurassic phase of rifting during which rift valleys formed and filled with continental red beds. Second, as rifting progressed through Early and Middle Jurassic time, continental crust was stretched and thinned. This thinning created a broad zone of transitional crust, which displays modest and uneven thinning with block faulting, and a broad