Department of the Gulf north. On November 3, 1863, the northern boundary was extended to latitude 33° north. On July 25, 1863, the department/district was transferred to the Department of Mississippi and Eastern Louisiana. It remained in that department only until January 28, 1864, when it was transferred to the Department of Alabama and Eastern Mississippi. Upon being transferred, the department/district boundaries were redefined as beginning at the mouth of the Pearl River, running north to latitude 32° north, east to the Georgia State line and south to the Gulf of Mexico. On May 8, 1864, the boundary was again modified to define the
Gulf of Mexico basin Mexico which penetrated the Late-Triassic and Early-Jurassic strata, filling the extensional graben features. The Gulf of Mexico basin red beds are specifically named the Eagle Mills formation, located directly beneath the salt, evaporite and marine sediments deposited during the Jurassic, and often found with the diabase dikes and basalt flows mentioned above. 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. It is atop these Precambrian plate fragments that the mainly carbonate and