TILE GULF PLAINS. These are most simply de fined as a continuation of the Atlantic Coastal Plain, or another part of the younger fringe of the continent. In central Georgia and Alabama the younger formations abut on the older rocks of the southern Appalachians and mark approxi mately the encroachment of the later seas.. By gentle uplift the marginal sea bottoms of the Gulf were laid bare, and form the fiat lowlands of this semi-tropical region. This explains in brief the origin of the peninsula of Florida, most of whose surface has now an altitude of less than 100 feet. A gentle uplift of the sea bottom brought this land into existence. Cavernous openings in the rocks, underground streams, and springs of great volume result from the presence of extensive limestone formations as part of the bed rock of the region. The seaward edge of this land abounds in sand bars, coral reefs, and man grove swamps, and this single State, counting its main shores, its bays and numberless islands, has more than 4000 miles of shore line. It is
proposed to open a way for quiet water navi gation down the entire east coast of Florida.
Westward from Alabama, the Mississippi River (q.v.) becomes the controlling feature in the topography of the Gulf region. The broad Gulf plain occupies a large part of southern and east ern Texas. Assin the region to the eastward, the younger rocks have been made into land by uplift and retreat of the sea. As a rule the surface slopes gently toward the Gulf, but with escarp ments and great local variations of topography. Sonic areas are prairie, while others are heavily forested, and the rise to the northwest leads first to the great plateau, or Llano Estaeado, and then to the mountains of the lloeky Mountain Mange. The shore line is a long crescent, bordered by ex tensive sand bars, which inclose stretelies of quiet water. Galveston is On one of these bars, and it is thus exposed to the Golf hurricanes.