WSP02127

• File Number: 8112.600
• Description: Arkansas White Red Basins Interagency Committee - AWRBIAC
• Basin: Arkansas
• Water Division: 2
• Date: 8/1/1976
• Title: Technical Memorandum - State Regional Futures and Problem Lists -- Activity 2 Phase II -- 1975 National Assessment --- part 1 of 3 -- Cover Page - page 134
• Water Supply Pro - Doc Type: Report/Study

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A. State-Regional Futures.

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ARKANSAS

Introduction

Physical Description

The landform of Arkansas belongs to two major physiographic
divisions of the nation--the Atlantic Plain and the Southern Interior
Highlands. Physiographic divisions are divided into provinces; and
those in turn into sections. The following outline will illustrate
the relationships between these units.

Atlantic Plain Division
Coastal Plain Province
West Gulf Coastal Plain
Mississippi Alluvial Plain
The Ozark Plateaus Province covers northern Arkansas and extends into
eastern Oklahoma and to the Missouri River to the north. They consist
of sedimentary rock which has undergone massive uplift and which remains
relatively horizontal with only minor deformations. Stream erosion has
removed much of the original surface rock and has dissected the area
into hills and low mountains although some plains occur.

Southern Interior Highlands Division
Ozark Plateaus Province
Ouachita Mountain Province

The Ouachita Mountains Province lies in the west central part of the
state. The Ouachita Mountains are also of sedimentary rock but here it
has been folded to create generally parallel ridges and valleys which
have an east-west orientation. Most of the mountain ridges are narrow,
with steep slopes; crests tend to be sharp; valleys are generally rather
broad. Within the Ouachitas, the sections are distinguished largely by
the spacing of the folds. Through the Ouachita Mountain Province passes
the Arkansas River.

The West Gulf Coastal Plain covers the southwestern part of Arkansas
and extends eastward about three-fourths the width of the state. This
section stands between 100 and 500 feet above sea level. It has a gently
rolling surface, only moderately dissected by streams. Much of the sur-
face material is unconsolidated sands deposited in the sea which once
covered the area.

The Mississfppi Alluvial Plain is generally the eastern fourth of
the state; it is a trough filled by stream sediments of great depth.
The surface is generally flat, with local relief of less than 100 feet.
Elevations range from 500 to 100 feet, decreasing southward. Crowleys
Ridge is a striking irregularity upon the Plain. It is 3 to 12 miles wide,
rising 200 feet above the Plain in the north and 100 feet in the south.
It has a deep cover of loess, fine wind-deposited material, and is
dissected into a rolling hill region.

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