Centrally located in the interior southeastern United States, Tennessee has a land area of 26,443,500 acres or 41,318 square miles. The topography of Tennessee is among the most varied in the United States, ranging from wide level river bottoms in the west to high mountain peaks in the east, with valleys, plateaus, basins, and other features in between. Physiographic regions are important background knowledge for archaeologists, due to the often extensive interaction between human culture and the local environment.
Nine physiographic regions of Tennessee are described following.
The Unaka Mountains are a portion of the Appalachian Mountains in Tennessee (called the Blue Ridge elsewhere). The Unakas include the Great Smokies (ranges included within the Great Smoky Mountains National Park), and such mountains as Chilhowee, English, Bean, Meadow Creek, Holston, Starr, Roan and others (Miller 1974:3). These mountains are characterized by rugged terrain, heavily forested slopes, and rushing streams with waterfalls. Interspersed among these ranges are large coves, such as Cades, Wear, Tuckaleechee, and Bumpass. The valleys range in elevation from about 1000 feet above sea level in the south to 1500 feet in the north, and several peaks are more than 6000 feet in elevation.
The Unaka Mountains lie in the northwestern portion of the Blue Ridge subdivision of the Southern Appalachian Mountains. Mountains in this region consist of heavily forested ridges with rugged terrain and many rushing streams (Miller 1974:3). Elevations in the valleys range from 1000 feet AMSL in the south to 1500 feet in the north with ridges and peak s reaching between 2500 and 6300 feet. The Unaka range, the crest of which forms the Tennessee-North Carolina state line contains many westwardly oriented ridges separated by steep narrow valleys, although the general trend is northwesterly. Major streams such as the French Broad, Ocoee, and Watauga Rivers tend to have cut channels through rocks with the least resistance.
Mountains in the Northern part of the range are composed of
Lower Paleozoic limestone, dolomites and shale with exposures of
Precambrian igneous and metamorphic basement rocks such as tuff, rhyolite,
granite, schist and quartzite. The many formless mountains to the south
along the state line are mainly composed of Precambrian sedimentary and
metamorphic sandstone, conglomerate, arkose and siltstone. These include
the Great Smoky Mountains (King and Ferguson 1960:9).
The Unaka Mountains are part of the Southern Appalachian section of the
Oak-Chestnut Forest region. The lower slopes of the Unaka range are
mostly dominated by Oak-chestnut and mixed mesophytic forests including
such species as buckeye, sugar maple, yellow birch, beech, and hemlock.
The higher slopes are occupied by beech-maple and spruce-fir communities
with grassy and rhododendron balds occurring above 5500 feet. In many
other areas, including the Great Smoky Mountains, valleys and flats at low
elevations support mixed deciduous-coniferous and spruce-fir communities
(Braun 1950:201,214-215).
The climate of the region varies considerably between the high and low
elevations. Summers are normally hot in the valleys and cooler in the
higher elevations. Average yearly temperatures range from 50 in the
mountains to 55 degrees Fahrenheit in the valleys. Yearly precipitation
ranges from about
45 to 50 inches, much of it occurring in the summer months. Snowfall
occurs frequently at higher elevations (USDA 1953b:6, 1955:8, 1956:10).
The Valley and Ridge is sometimes referred to as the Valley of East
Tennessee. Numerous elongate ridges and intervening valleys, all trending
in a northeast-southwest direction, characterize this physiographic
region. This orientation is the result of folding and fracturing during a
mountain building episode 230 to 260 million years ago.
The Valley and Ridge extends from the Unakas on the east to the escarpment
of the Cumberland Plateau on the west. The most prominent ridges are to
the north -- Clinch and Powell Ridges, and Bays Mountain. To the south
the highest and longest ridge is Whiteoak Mountain, between Chattanooga
and Cleveland. These ridges range in elevation from 1495 feet (Whiteoak
Mountain) to 3097 feet (Bays Mountain). Valleys to the north average
about 1000 feet in elevation and to the south about 750 feet.
The Valley and Ridge physiographic province occurs in Tennessee as a
section of a long narrow belt of the Folded Appalachian geosyncline
(Southern Appalachian Mountains) and ranges in width from 100 to 30 miles
from north to south (Fenneman 1938:265). Folding and fracturing during
late Paleozoic times resulted in the northeast-southwest orientation of
ridges and intervening valleys, which are underlain by respectively
resistant and weaker rocks. Valley elevations are about 750 feet AMSL in
the south and 1000 feet further north. Ridges generally reach to about
1500 feet with some mountains approaching 3000 feet. The eastern
escarpment of the Cumberland Plateau and the Blue Ridge subdivision (Unaka
Mountains) of the Appalachian Foldbelts mark the boundaries of this
region. Bedrock is shown through folding activity to be composed of
Ordovician and Cambrian limestone, shale, and sandstone with outcrops of
Devonian and Mississippian limestone and chert in northern areas (Miller
1974:3). Cave development occurs at lower elevations.
Streams generally follow the narrow valley floors or cut across the strike
of the ridges. The Tennessee River flows southwest through the region.
Principal feeders from the north are the Clinch, French Broad, and Holston
Rivers. Major tributaries from the east are the Hiwassee and Little
Tennessee Rivers.
The Valley and Ridge section is located in the Ridge and Valley Section of
the Oak-Chestnut Forest region. Ridge crests support such species as
white and red oak, sour gum, sassafras, and chestnut. Lower mountain
slopes contain mixed mesophytic communities of beech, white oak, and
buckeye. Valleys floors are dominated by white oak and occasionally tulip
and hickory. In the large valleys to the south, there occurs a gradual
change from an oak-chestnut to an oak-pine type forest (Braun 1950:232,
238).
The climate of this region varies locally depending on topography and
prevailing winds, but is generally characterized by warm summers and
short, mild winters. The average yearly temperature ranges from 50 to 60
degrees Fahrenheit north to south. Rainfall is abundant in winter and
spring, averaging between 45 and 55 inches per year. Fall is typically
the driest season (USDA 1953c:6, 1958:2, and 1979:2).
The Cumberland Plateau is part of the Appalachian Plateau Physiographic
Province as described in Fenneman 1938, which consists of a tableland
region that extends from western Pennsylvania to northeastern Alabama.
The portion of the Plateau that lies in Tennessee forms a striking cuesta
thirty to fifty-five miles wide and averages from five hundred to over a
thousand feet higher than the adjacent Valley and Ridge to the east and
the Interior Low Plateau to the west. This elevated tableland is the
result of highly resistant caprock of Pennsylvanian age sandstone and
conglomerate. Because of its striking geologic and physiographic
features, the Cumberland Plateau has long been accorded regional
distinction by geographers (Fenneman 1938; Thornbury 1965). The
Cumberland Plateau is part of the Appalachian Plateau Physiographic
Province as described by Fenneman 1938), which consists of a tableland
region that extends from western Pennsylvania to northeastern Alabama.
The portion of the Plateau that lies in Tennessee forms a striking cuesta
thirty to fifty-five miles wide and averages from five hundred to over a
thousand feet higher than the adjacent Ridge and Valley Province to the
east and the Interior Low Plateau's Province on the west. This elevated
tableland is the result of highly resistant caprock of Pennsylvanian age
sandstone and conglomerate that has impeded the erosional processes
exposing the limestone regions to the east and west. The Plateau is
considered a true peneplain, exhibiting a broad, undulating surface
submaturely dissected by young valleys whose steepness and depth increase
toward its edges (Fenneman 1938:337).
High escarpments having an average elevation of approximately 900 feet
above sea level mark the eastern and western boundaries of the Plateau.
On the east the escarpment is a high, almost unbroken linear scarp that in
places rises a thousand feet above the Ridge and Valley region. This
portion of the Plateau is known as Walden's Ridge. The western escarpment
is less pronounced and very irregular due to the number of deeply
entrenched drainages that have sapped the caprock at its edges carving
deep valleys into the underlying limestone and leaving numerous sandstone
capped outliers isolated from the main body of the Plateau. Although the
northern and southern boundaries of the Plateau are less pronounced, the
northern portion of the region consists of the Cumberland Mountains with
elevations exceeding 3000 feet above sea level (Miller 1974:3). The
selection of a northern boundary for the Cumberland Plateau is arbitrary,
the division being based on the greater degree of dissection of the
Plateau to the north (Fenneman 1938:333).
The most uniform area of the Plateau includes all formations of
Pennsylvanian age that are bounded by the escarpment of Walden's Ridge and
Cumberland Mountains on the east, by the Tennessee River on the south, by
the Cumberland River on the north, and by the continuous escarpment along
the western edge of the caprock. These boundaries delineate an upland
area of approximately 13,000 square kilometers, which is relatively
uniform with respect to salient characteristics of physiography, geology,
hydrology, and the biotic and edaphic factors typical of the submaturely
dissected Cumberland Plateau. In this manner a relatively homogenous
study unit is defined in which the influence of environmental attributes
may be expected to have a direct and observable influence on the structure
of human adaptive systems (Ferguson and Pace 1981:2).
Geologically, the Plateau is formed from horizontal rock strata; however,
the development of several structural folds and fault systems has had a
pronounced effect on local topography. The most obvious of these systems
is along the eastern escarpment, particularly in northern Tennessee and
southern Kentucky, where a great block fault forms the structural basis
for the Cumberland Mountains, an area of pronounced elevation and relief.
Likewise the Crab Orchard Mountains of the central Plateau are the
remainder of an anticlinal system that elsewhere developed into the
Sequatchie Valley.
The Sequatchie Valley extends 200 miles from the east-central portion of
Tennessee into northeastern Alabama (Sterns 1954). Throughout its length
the valley is almost perfectly straight. The valley is bound
latitudinally by the notched escarpments of Walden's Ridge to the east and
the Cumberland Plateau to the west (Elder 1958:2). The Sequatchie Valley
is considered a part of the Cumberland Plateau and represents the most
striking topographic feature of the Plateau region (Thornbury 1965:148).
Along much of its length, the valley is representative of an asymmetrical
anticlinal fold. This structure begins at the northern portion of the
valley in the Crab Orchard Mountains as a nearly symmetrical fold
involving Pennsylvanian sandstones and conglomerates. The fold is
breached just south of the Crab Orchard Mountains in a karst basin known
today as Grassy Cove.
Drainage of the Plateau (including the Sequatchie Valley) is
characteristically dendritic in pattern. Major drainage systems of the
Plateau may be divided into two principal groups, consisting of those that
are tributary to the Cumberland River system and those that are tributary
to the Tennessee. The Cumberland River tributaries include the Caney
Fork, Obey, Wolf, Big South Fork, and Elk Rivers as well as Jellico Creek.
Those of the Tennessee River include the Tennessee, Sequatchie, Emory,
Clinch, and Elk Rivers as well as Battle Creek (Ferguson and Pace 1981:
3). Several of these drainages actually drain relatively small portions
of the Plateau. However, the Emory, Big South Fork, and Caney Fork Rivers
drain in excess of 20% of the area defined, a combined total area of over
7000 square kilometers. The drainage of the Big South Fork of the
Cumberland River contains approximately 3200 square kilometers of the
Plateau or roughly 24% of the total area defined within the study unit.
The Cumberland Plateau is the southern portion of the Appalachian Plateau
physiographic province. The topography is that of a true peneplain,
generally flat with some moderate undulation (Fenneman 1938:337).
Ranging in width from about 30 to 60 miles, the eastern boundary is a
large escarpment with an average elevation of about 900 feet AMSL.
Elevations on the plateau surface range from 1700 feet to about 2000 feet.
The western escarpment rising above the Eastern Highland Rim is irregular
and dissected by steep valleys. Two linear valleys, the Elk and
Sequatchie, an anticlinal valley, were formed from extensive faulting and
folding during a period of Appalachian mountain building. The Cumberland
Mountains, with elevations exceeding 3000 feet, occur in the northern part
of the region (Miller 1974:3).
The Tennessee River, forming the southeastern boundary of the region, has
many east-flowing tributaries that drain the eastern Plateau. These
include Falling Water, Mullens, Piney and Suck Creeks and the North
Chickamauga River. Tennessee River tributaries include the Battle Creek,
and the Clinch, Elk, Emory and Sequatchie Rivers. The region contains the
Cumberland River divide and its tributaries, the Big South Fork, Caney
Fork, Obey and Wolf Rivers that generally flow west-northwest.
A cap of resistant Pennsylvanian sandstone and conglomerate up to 1000
feet thick covers the plateau surface. Much of it consists of the
Rockcastle Conglomerate in the north and Sewanee Conglomerate and Gizzard
Sandstone in the south. Dissecting the plateau are numerous deep gorges
that form prominent cliffs along their perimeters. Paleozoic age
limestone, shales, siltstones, and coal that are exposed in gorges and
valleys underlie the sandstone cap. Karst development is common where
limestone is exposed, with large caves forming generally below 1500 feet.
Soils in the Plateau are chiefly formed from parent material and,
consequently, are sandy loams that are fairly well drained. Silt loams
and residual clays occur on slopes and valley floors. Loess of western
origin is nearly absent from the region (USDA 1981:2).
The Cumberland Plateau falls within the Cumberland and Allegheny section
of the Mixed Mesophytic Forest region. It is described as one of the
oldest and most complex associations of the eastern deciduous forests.
Where the region is deeply dissected, typical dominant species include
tulip, poplar, white and red oak, hemlock, basswood, beech, chestnut, and
sugar maple. The old peneplain surface is dominated by oak or oak-hickory
forest (Braun 1950:39,114). Because of its higher elevation, the region
maintains a temperate climate with average temperatures lower than the
adjacent regions. General weather conditions are subject to microclimatic
variation between areas. The annual mean temperature is 55 degrees
Fahrenheit in the northern Plateau and about 4 degrees higher in the
south.
Precipitation averages about 50 inches per year, much of it as rain
occurring from late winter through early spring. Snowfall averages about
10 inches per year (Ferguson and Pace 1981:7-10).
The eastern subdivision of the Highland Rim region is characterized by
generally undulating terrain except in the flat south-central portion
known as the Barrens. About 25 miles in width, the eastern Rim is set
apart from the Central Basin by a west-facing dissected escarpment forming
a bench with an average elevation of slightly more than 1000 feet (Miller
1974:6). The constituent bedrock is composed primarily of Mississippian,
St. Louis, and Warsaw limestone with Fort Payne chert underlain by
Chattanooga Shale that forms a large part of the escarpment. Separating
the Highland rim from the Cumberland Plateau are steep-walled valleys
which are often wide in proportion to their length, largely due to
solution (Fenneman 1938:417). The region is more prolific in karst
development than the Western Rim, with the southern portion containing
extensive cave systems. Major drainages of the region are the Caney Fork
and Cumberland Rivers. The Elk River, a tributary of the Tennessee River,
drains the southern Eastern Highland Rim.
Most of the region is covered with a silty mantle of loess underlain by
residual clays or cherty clay. Where the mantle has been thinned by
erosion the clay is red, a typical characteristic of limestone soils with
high iron oxide content. Drainage in the region is moderate to good.
The colluvial soils of the valley floors are rich in organic matter and
are well suited to agriculture (USDA 1963:97).
Similar to the Western Highland Rim, this region is part of the
Mississippian Plateau section of the Western Mesophytic Forest region,
supporting a mixed oak-tulip-chestnut forest with accessory stands of
beech and hemlock. Relic stands of mixed hardwood-white pine occur on
some bluffs above streams. The Barrens are closely related with karst
topography and were once tall grass prairies (Braun 1950:152-155).
Climate of the eastern Highland Rim is seasonally variable with generally
mild winters and warm summers. Rainfall averages between 50 ad 55 inches
per year and is heaviest in late winter or early spring. The average
yearly temperature is variable from place to place and it about 60 degrees
Fahrenheit (USDA 1959a:88, 1972:2).
The Central Basin is an elliptical depression surrounded by the Highland
Rim. It was formed by the relatively rapid erosion of an uplifted area of
bedrock called the Nashville Dome during late Paleozoic times.
Approximately 125 miles north-south and about 60 miles east-west, the
Basin is subdivided into inner and outer sections. The inner section is
generally smooth and gently rolling in contrast to the higher and more
deeply dissected outer Basin (Miller 1974:5). The average elevation of
the inner Basin is about 600 feet above mean sea level while the average
elevation of the outer basin is about 750 feet. Siliceous rocks cap the
hills of the latter, reaching heights of 1,300 feet. Major drainages of
the region are the westward flowing Cumberland River and the Duck and Elk
Rivers flowing northwest and southwest respectively. Two major
tributaries of the Cumberland River draining the inner basin are the
Harpeth and Stones Rivers. Floodplains of these and other streams are
similar in both sections, generally low gradient and meandering (Edwards
et al 1974:4). Bedrock is primarily Ordovician limestone, shale and
dolomite in the outer Basin with the Mississippian Fort Payne formation
overlying Chattanooga shale marking the contact between the Basin and the
Highland Rim (Wilson 1949:2). The inner basin is generally covered with
limestone of the Stones River formation with patches of bare platy rock
and thin topsoil with glade areas supporting red cedar trees. The region
is moderate in karst development with many sinkholes and some large caves
present, notably in the glade areas.
Soils of the Central Basin are for the most part high in silt content and
rich in calcium derived from the parent limestone. Thick deposits of
alluvium and colluvium occur in valley floors and loess covers a small
part of soils throughout the region. Saline groundwater discharge in some
areas has resulted in the formation of salt licks and springs which were
utilized during prehistoric and historic times (Edwards et al
1974:115).
The Central Basin lies within the Western Mesophytic forest region and
originally supported a forest of large trees. Climax communities
including oak, hickory, tulip tree, beech and chestnut occur in hilly
areas. Lower hills and flats support hickory, winged elm, hackberry, and
blue ash. Deciduous species within the cedar glades are predominantly
hickory, oak and sugar maple (Braun 1950:132).
The climate of the region is variable between different elevations and
geographic points. The mean annual temperature is 60 degrees Fahrenheit.
Rainfall is uniformly distributed, averaging 45 to 55 inches per year with
most occurring in late winter or early spring. Fall is typically the
driest season (Klippel and Bass 1984:5).
The Western Highland Rim in Tennessee is the western subdivision of the
Highland Rim of the Interior Low Plateau physiographic province.
Entirely surrounding the Central Basin, the Highland Rim is characterized
by rolling terrain dissected by sharply incised valleys with numerous
streams (Fenneman 1938:416). Elevations range from about 700 to 1000 feet
above mean sea level with the topography of the southern part generally
more level than in the north. Major drainages in the region are the Duck
and Buffalo Rivers (tributaries of the Tennessee River), and the
westwardly flowing Cumberland River. Underlying bedrock of the region is
chiefly Mississippian limestone, chert, shale, and sandstone with
exposures of Devonian, Silurian, Ordovician, and Cambrian limestone,
chert, and shale. The latter are exposed primarily in the drainages of
the Buffalo and Duck Rivers. Karst development features such as caves and
sinkholes are present on the northernmost counties of the region (Miller
1974:5).
The well-drained upland and imperfectly drained bottomland soils are
predominately sandy clay and gravelly silt loams. Terraces near the
bottomlands consist mainly of cherty silt loams and silt loams (USDA
1946:16).
The Western Highland Rim is part of the Mississippian Plateau section of
the Western Mesophytic Forest region, where oak forest was formerly
predominant. A mixed oak-tulip-chestnut type forest with accessory stands
of beech, hickory, and sugar maple occupies the well-drained areas.
Poorly drained lowlands contain oak, gum, red maple and beech (Braun
1950:154).
In this region, winters are mild and summers and hot and periodically dry.
The yearly average temperature is 60 degrees Fahrenheit with 50 inches of
precipitation occurring mostly during the winter and early spring (USDA
1959b:2 and 1975:2).
The Western Valley region comprises the channel,
floodplain, and terraces of the northward flowing Tennessee River, along
with the West Tennessee Uploads east of the Tennessee Divide. The uplands
section, is dissected and hilly, and is 20 to 30 miles wide with an
average elevation of about 500 feet above mean sea level. Major drainages
flowing into the Tennessee River are the Beech, Big Sandy, and White Oak
Rivers (Miller 1974:7). Sandy Cretaceous underlies the area and Eocene
deposits. Soils are generally well-drained sandy loams enriched by a thin
mantle of loess (USDA 1960a:7).
The Tennessee Valley proper is in places as wide as 20 miles with the
floodplain portion ranging in width from 3.5 miles near the Alabama state
line to 1.5 miles in Benson and Houston counties in the mid-northern part
of the state. Elevation of the floodplain ranges from about 350 to 400
feet above mean sea level. The dissected meandering river valley, with
ridge crests of the West Tennessee Uplands and Western Highland Rim rising
200 to 300 feet above the floodplain on their side, contains remnants of
alluvial terraces and natural levees. Considerable erosion of these
features has taken place since the impounding of Kentucky Lake Reservoir
by the Tennessee Valley Authority (Miller 1974:7). Major tributaries of
the river in the Western Valley are the Big Sandy and Duck Rivers.
Pleistocene and recent alluvial deposits of sand, silt, clay, and gravel
up to 60 feet thick cover the valley floor. The floodplain and adjacent
ridges are underlain chiefly by cherty Devonian-Mississippian Fort Payne
limestone and Chattanooga Shale (Hardeman 1966). Soils of the floodplain
and terraces are primarily fine sandy loams and silt loams. The
surrounding uplands soils are excessively drained sandy clay loams formed
from cherty limestone and Coastal Plain alluvium (USDA 1948:15 and
1960b:123).
The bluffs of the West Tennessee Uplands comprise the western boundary of
the Mississippian Plateau section of the Western Mesophytic Forest region.
Forests in the valley are of a mixed white oak-hickory type with an
abundance of species in the southern part. Other species occur mainly in
ravine communities and include beech, tulip tree and sugar maple (Braun
1950:154-156).
Short mild winters and warm summers that are hotter in the southern
portion of the state generally characterize the climate of the region.
The mean yearly temperature is between 58 and 60 F with 52 inches of
precipitation that is heaviest during the winter and early spring
months.
The West Tennessee Coastal Plain is defined as the area west of the
Tennessee River divide and to the east of the loess hills that flank the
Mississippi River Valley.
The Coastal Plain region, a portion of the
East Gulf Coastal Plain (Fenneman 1938) is an area of relatively low
relief. Herein, a slight departure from
Fenneman's (1938) division has been made. While Fenneman includes both
the West Tennessee Uplands and the West Tennessee Plains in this region,
the West Tennessee Uplands east of the Tennessee
River divide has been included in the Western Valley. The uplands grade into the extensive West Tennessee
Plain that is less hilly and nearly flat in some areas. Major drainages
flowing west to the Mississippi River are the Forked Deer, Hatchie,
Loosahatchie, Obion and Wolf Rivers. Deposits of loess up to 65 feet
thick underlie the West Tennessee Plain, with the thinnest part located in
the east where it merges with loessic Upland soil. This formation
overlies Eocene sand and clay deposits (Blythe et al 1975:4). The Plain
slopes gently westward extending to and including the Loess Hill Bluffs
(the belt of hills that rise 1250 to 250 feet above the Mississippi River
floodplain). The Loess Hill bluffs range in width from 5 to 15 miles and
extend north-south from Reelfoot Lake to Memphis (Fenneman 1938:80).
The Coastal Plain is included in the Mississippian Embayment section of
the Western Mesophytic Forest Region. The loess hills and upland areas
consist of a mixed mesophytic oak-hickory forest. Other species include
yellow pine, tulip tree, white ash, dogwood, wild black cherry, persimmon
and mulberry. Bottomlands in the region support swamp forests which
include cypress, elm, ash and cottonwood (Braun 1950:158). Relatively
mild winters and hot summers characterize the climate. Average yearly
rainfall is about 50 inches with most occurring in late winter and early
spring. The yearly mean temperature is 60 degrees Fahrenheit. (USDA 1953a:8, 1960a:2).
The Mississippi River Valley includes both the alluvial floodplain and the
adjacent loess bluffs that flank the east side of the Mississippi River
for much of its length. The Mississippi River alluvial valley is as much
as 5.5 km wide in the study area, with the Reelfoot Lake Basin being the
most prominent feature. Numerous oxbow lakes are presents, and the
meandering of the Mississippi River have played a major role in the
deposition preservation, and destruction of archaeological sites and
remains. The loess bluffs rise sharply above the valley floor, reaching
heights of over 40 m and slope gently eastward where they merge with the
Coastal Plain. The Mississippi
River floodplain
ranges in width from 15 miles near the Reelfoot Lake basin to about five
miles in the vicinity of Memphis and rises from 185 to 230 feet above mean
sea level. The line of hill slopes, forming the eastern boundary, is
known as the Loess Hill Bluffs, composed of silty Pleistocene loess up to
80 feet thick and underlain by fluvial deposits of sand, gravel, and
Eocene clay and sandstone of the Jackson formation (Blythe et al 1975:67).
The floodplain exhibits topographic features such as cutoffs, oxbow lakes
and natural levees formed by activities of the meandering river channel
which ceased downcutting about 9,000 year ago (Phillips et al 1951:7).
Soils of the bottomlands generally have been transported from the great
central plains and prairies. They are rich in organic matter and are
among the most fertile soils in the state. They range from excessively
drained sandy loams on the first bottoms to poorly drained clays on the
low floodplains (USDA 1970:6). The Mississippi River Valley in
Tennessee forms the contact between the Southeastern Evergreen and Western
Mesophytic Forest regions. Swamp forests of the alluvial plain consist
mainly of bald cypress and water tupelo with occasional red and silver
maple, pecan and water ash. The hardwood stands of higher elevations
include sweet gum, elm, sassafras, hackberry, and many species of oak.
The loess hills are part of the Western Mesophytic forest and are
dominated by oak-hickory forest which includes other trees such as beech,
tulip, cucumber, sugar maple, and basswood (Braun 1950:159-160 and
292-293). The climate of the region is characterized by generally mild
winters and hot summers with an average annual temperature of 60 degrees
Fahrenheit. Rainfall is abundant, averaging about 48 inches per year,
occurring mostly in winter and early to late spring (USDA 1969:2 and
1970:2).