Mississippi Gulf Coast Mississippi Gulf Coast The Mississippi Gulf Coast, also known as the Mississippi Gulf Coast region, or simply The Coast, is the area of southern Mississippi along the Mississippi Sound along the Gulf Of Mexico. The term has traditionally referred to the three counties that lie directly on the Mississippi Sound that meet up with the Gulf of Mexico within the state: Hancock County, Harrison County, and Jackson County. The U. S. Census Bureau divided the Metropolitan Statistical Area (MSA) for the Mississippi Gulf Coast in 2003, which previously had been the three coastal counties, into two MSAs that included two
Gulf of Mexico basin wherein thick Jurassic salts and evaporites could be deposited. These evaporites overlay a thick transitional crust, the local basement rock prior to rifting, and deposition of salts continued over the forming oceanic crust as rifting spread the sea floor throughout the Jurassic. It was during the Jurassic, approximately 140–160 million years ago, that the shape of the Gulf of Mexico as we know it was formed. The unique shape of the Gulf of Mexico, surrounded on all sides by continental crust, is the result of two different tectonic boundaries: an ocean-continent transform boundary, and a magmatic plume fueled seafloor spreading