he Southeast is divided into several physiographic divisions, including the Coastal Plain Province, Piedmont Province, Blue Ridge Province, the Southern Section of the Ridge and Valley Province, the Cumberland Plateau (part of the Appalachian Plateau), the Interior Low Plateau and other areas to the west of these. Bartram traveled in only the first three and these are the ones that will be discussed in detail.
The physiographic provinces that we see today are a result of climatic effects on the past and present geologic environment; the interrelation of wind, frost, heat, rain and snow and the different kinds of rocks in the area. Over time, and depending on the geologic structures, hogback ridges, gently rolling plains, sinkhole topography, sand hills, broad uplands and other features of the landscape have been formed. Each area tells its own story; limestone, for example, is altered both
chemically and physically, to form sinkhole topography with its interior drainage, as in the Dougherty Plain. Thick beds of sand for the Sand Hills. Large granitic masses form features like Stone Mountain and other rocks form the rolling Piedmont. Dipping quartzite beds form the prominent parallel hogback ridges. The foremost characteristic of the Cumberland Plateau is seen in broad remnants of a surface in which only shallow valleys of an older generation are found. Other areas in the region have equally distinctive characteristics, and all tell the story of time.
Despite the difference of their size, their political boundaries, physiographic provinces, or human occupancy (described elsewhere in this report), the subdivisions are interrelated with respect to water resources. Within the region, all water flows to the Atlantic Ocean or the Gulf of Mexico above ground in river systems and underground in aquifers. The routes intermingle—some of the water may be above or below ground several times before it reaches the sea, but regardless of its name and location at any given time, water is the common resource that unites the Southeast.
Coastal Plain Province
The Coastal Plain Province is divided into several aquifer areas, each area being determined by the geologic formations of which the aquifers are composed. The Coastal Plain is underlain by a thick sequence of permeable sedimentary deposits and rocks which contain relatively large amounts of usable water. The Coastal Plan aquifers are: 1. sand aquifers of Cretaceous age; 2. limestone and sand aquifers of early Tertiary age; 3. principal artesian (limestone) aquifer; 4. other aquifers, including the sand and gravel aquifer of Miocene and post-Miocene age of the area along the Gulf Coast to Louisiana; and the aquifers of Miocene and Pliocene age of the Atlantic Coast from Florida to North Carolina.
The Coastal Plain is an area of low topographic relief, but having considerable diversity in the hydrologic characteristics of a stream, particularly with reference to low flows. Because of this diversity it is convenient to subdivide the province into upper and lower parts.
Today, as during Bartram’s travels, agricultural and most other commercial activities are concentrated on the higher and drier ground of the Lower Coastal Plain. The depth of water here fluctuates with rainfall and the seasons. The sand tends to absorb streamflow, especially during drought when the water table falls. The sand also acts as temporary storage space to absorb some of the flood flows.
The land surface of the Upper Coastal Plain is composed of exposed sediments of sand aquifers of Cretaceous age, limestone and sand aquifers of early Tertiary age, and limestone of the principal artesian aquifer. This is believed to be their primary recharge area. The large base flow of the streams is recharge which has been rejected by the saturated aquifers to the south.
The topography of the Lower Coastal Plain is low, flat, and swampy where it borders the Atlantic Ocean and the Gulf of Mexico, and grades to low rolling hills at the inner margin. It is at lower altitude and has less relief than the Upper Coastal Plain.
In southern Louisiana, Mississippi and Alabama, low swales and flats occur between ridges that are poorly drained with wet acid soils. These contain unique and varied herbaceous flora. The Coastal Pine Meadows or Coastal Terraces border Mississippi Sound like a penumbra five to fifteen miles in width, except around bay heads and rivers where it widens to 25 to 30 miles. This region provides the upland border for most of the coastal marshes. The tree cover is predominantly pine in open stands which are often called savannahs; however, the oaks (Quercus Virginiana—live oak), magnolias and other hardwoods occur in abundance, especially along the coast.(2)
The Atlantic Coast Flatwoods Land Resource Area extending from North Carolina to Florida is the part of the Coastal Plain Province in which Bartram spent most of his time, and is therefore worthy of special attention. The soils in this area have developed from nearly level beds of unconsolidated sands, clays, and soft limestones; most are poorly drained. Erosion has been slight. Extensive areas of tidal marshlands occur along the coast and extend for several miles up the rivers. Beaches are wide with gentle slopes and backed by parallel ridges of sand dunes.
In December, 1977, the National Aeronautics and Space Administration compiled for this study the tidal marshland acreage for five of the seven Atlantic and Gulf Coast states in the region:
State Acreage
Georgia 429,294
South Carolina 427,652
Florida 169,708*
Mississippi 66,933
Alabama 38,259
Total 1,131,846
*(Does not include mangrove swamp.)
Comparable data for the other two states—North Carolina and Louisiana—is not readily available.(3)
The overall value of this 1.1 million acres is incalculable due to the manifold contributions which the complex coastal environmental area contributes to the populace.
During Bartram’s travel, he noted trees were being cleared so that rice, indigo, corn and potatoes could be planted. Indigo and rice are no longer grown in the region to any significant extent, but corn and potatoes are still significant crops. In addition to these, other kinds of vegetables, soybeans, and pasture land for cattle are much in evidence along the coast. The most important use for the land, however, is the production of timber.
Since the early 1930’s nearly all of the salable cypress has been removed from the region for fence posts, canoes and lumber. The cypress that remains is of inferior quality.
Several times in his Travels Bartram remarked on the stands of large size, native longleaf pine. Since the advent of wood pulp mills in the 1930’s, much of the longleaf pine has been cut for pulpwood and lumber. In an effort to fill the ever increasing demand for pulpwood, slash pine seedlings have been planted on millions of acres of this region. The slash pine’s more rapid rate of growth shortens the pulpwood rotation. Thus, commercial factors have affected a major silvicultural change in the Upper and Lower Coastal Plain portions of the region. Blackbeard Island, Georgia, has one of the remaining larger stands of virgin longleaf pine.
Fall Line
The Fall Line is a transition zone five to forty miles wide, between the Piedmont Province lands and the Coastal Plain Province. This line was created by the downward-cutting streams stripping the more easily eroded sands of the Coastal Plain from the underlying crystalline rocks. It is an area of considerable botanical and zoological interest, for here the flora and fauna of the Coastal Plains and Piedmont Provinces intermingle to produce a diversity unmatched in either province alone.
Piedmont Province
North and West of the Coastal Plain is the Piedmont Province. The area is underlain by massive crystalline rocks, both metamorphic and igneous. Among the igneous are granites, pegmatites, and diabases. The metamorphic rocks consist of a variety of gneisses, schists, phyllites, meta-sediments, and meta-volcanics.
The rocks yield small amounts of water to domestic users, small cities and low water demanding industries. The crystalline rocks’ area is considered as a single aquifer area because of the relatively low yield of the rocks. The province extends from the Gulf Coastal Plain to the Atlantic Coastal Plain to the Central Lowland.
The Piedmont Province is the non-mountainous portion of the older Appalachians. Its surface is the result of degradation, since the underlying rocks are deformed. Rarely is the surface parallel to the beds of rocks, and nowhere is the original surface preserved.
So far as this extensive region has unity, it is found in the results of repeated uplifts, involving for the most part greater altitude and stronger relief than that of adjacent regions. The most pronounced differences in present topography are due to differences in rocks, either in their material constitution or in structural features made during older uplifts. Most of the province boundaries may be defined in terms of rocks and structure as well as those of topography.
The typical landscape of the Piedmont is a rolling surface of gentle slopes with minimal relief (averaging about 50 feet) cut by or bounded by valleys of steeper slope and greater depth (often several hundred feet). Near the larger streams, tributaries cut through deep and steep valleys, which, traced headward, become wide, shallow, and of gentle gradient. The deeper valleys are those of rejuvenated streams.
Ground water was the principal source of water supply for the colonists during the early development of the region. It wasn't until the end of the 19th century that many of the larger cities in the Piedmont outgrew their well fields and springs and developed water supplies from the rivers.
When white men moved into Indian lands in the Piedmont, they found areas with wonderful soil and large deciduous and evergreen trees. In these places the decayed vegetation compost was a foot deep. Bartram appreciatively described the forests and bright clear streams filled with beautiful fish. In the nineteenth and early twentieth century, land clearing was accelerated so that cotton could be planted. The cotton gin was indirectly responsible for stripping most of the land of trees. Careless practices led to a rapid loss of topsoil and exposure of the red clay that Bartram described as “tough” soil. The beautiful streams became silted, making navigation difficult, and leaving only certain varieties of fish.
Blue Ridge Province
The Blue Ridge Province is the belt of mountains west of the Piedmont Province. The mountains are remnants of a former highland which antedated the lower peneplains on either side. Peneplain is a land surface worn down by erosion nearly to a plain. The northern half of the province is a narrow belt, rarely 14 miles wide. The southern half broadens to a maximum of 70 miles and it increases in height. It extends from northwest Maryland, southwest through North Carolina, into and ending in north Georgia. Remote valleys shelter people who preserve old ways of life and speech. Compared to the Piedmont and Coastal Plain Provinces, the Blue Ridge Province is thinly populated. There are 46 peaks and 41 miles of divide above the level of 6,000 feet; also, 288 more peaks and 300 more miles of divide are above 5,000 feet.(4) Many of the most extensive high levels are near the margins on the southeast and northwest sides, both fronts being steep. Most of the boundary is also fairly simple, but it is complicated by a few large outliers in North Carolina and somewhat obscured by smaller ones in Georgia. The main divide is near the southeastern margin and bears the name Blue Ridge.
2. Lionel N. Eleuterius, “The Plant Life of the Coastal Mainland Associated Waters and Barrier Islands of Mississippi,” Guide to the Marine Resources of Mississippi, Irby McCaughan, Editor.
3. The Bartram Trail Conference would like to thank the National Aeronautics and Space Administration for compiling this information.
4. Horace P. Morgan, Bartram Trail Conference Technical Study, op. cit.; see also: Nevin M. Fennemen, Physiography of the Eastern United States, New York, 1938.
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