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 on top, by siliciclastic, eolian, playa and other sediments characteristic of arid terrestrial environments closer to shore, implying that at certain times during deposition, sediments accumulated almost up to sea level. 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. Nearer the depocenter, which for the Gulf of Mexico basin was towards the spreading center, terrestrial sediments grade into marine shales and limestones. Post salt deposition, the strata recorded millions of years of marine flooding sediments, carbonates from coral reefs, thick sandstones, and eventual