Georgia is crossed by five distinct physiographic provinces, based on similarities in land formations, elevation, rocks and minerals, soil, and other characteristics. They are the 1) Coastal Plain, 2) Piedmont, 3) Blue Ridge, 4) Ridge and Valley, and 5) Plateau. You can see this regions marked in the accompanying maps; below is a description of each region.
Coastal Plain
For more on the Lower Coastal Plain, see the New Georgia Encyclopedia.
Georgia’s largest geographical region is the Coastal Plain; it covers approximately 60 percent of the state, from the Atlantic Ocean to the Fall Line. In prehistoric times, this area of what is now Georgia was covered by ocean. Ocean waves slowly wore down hills and other land formations as they advanced inland. As time passed, countless numbers of seashells and other remains of ocean life sank to the ocean floor. Tightly packed, they eventually became beds of soft rock called limestone. Over time, rivers and streams deposited large amounts of soil, clay, and rock that had eroded from the hills and mountains to the north into the ocean. This eventually caused thousands of feet of sediment - or settled deposits - to cover the ocean floor.
Along the eastern states - like Georgia - the Coastal Plain’s interior boundary is marked by the Fall Line. The Fall Line is actually a region several miles across. It marks the area reached by the prehistoric ocean’s shoreline. Land north of the line is higher in elevation than land to the south, causing rivers to pick up speed as they travel - or fall - through this zone. South of the Fall Line - in the Coastal Plain - the ground is soft and sandy. Rivers become wider, deeper, and move more slowly, making navigation by large boats possible. This was very important to Georgia history, as major settlements - later cities - grew along the Fall Line, like Augusta, Milledgeville, Macon, and Columbus.
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Piedmont
Georgia’s second-largest geographical region is the Piedmont; while it is the second largest in size, it contains the highest population. This hilly region makes up approximately 30 percent of the state and lies between the mountainous regions of north Georgia and the Coastal Plain. Along the southern boundary, the Piedmont sits approximately 500 feet above sea level, but elevations can range up to 1700 feet at the southern edge of the Blue Ridge Mountains. This region consists primarily of rolling hills with many valleys. In some areas the hills are quite tall and almost appear to be mountains themselves.
Large areas of solid rock are found just beneath the earth’s surface in the Piedmont. This is called bedrock; consists of such stone as granite, gneiss, and marble. Piedmont bedrock is usually very hard, not like the sedimentary rock of the Coastal Plain. Because of this, it is normal to see large areas of exposed bedrock - called outcrops - where the soil has been washed away. Other evidence of bedrock can be seen in river beds, along highways, and on some hillsides.
For more on the Piedmont, see the New Georgia Encyclopedia
Numerous streams and rivers cross the Piedmont, usually flowing from north to south. Because of the bedrock, streams tend to have shallow beds, with narrow banks. Exposed rocks create rapids - which makess navigation impossible for large boats.
A common feature of Piedmont soil is its distinctive red color- the result of iron minerals found in granite and other rock. Erosion and weathering cause exposed rock in outcrops to break down into iron and other minerals. When Water is mixed in with the iron - it produces rusty red soil often called “Georgia red clay.”
Georgia’s most visually stunning geographical region is the Blue Ridge. The Blue Ridge Mountains are the highest in the Appalachian Highlands. This range reaches from northeast Georgia to southern Pennsylvania; it contains the highest elevations east of the Mississippi River. Georgia’s highest mountain - Brasstown Bald (4784 feet above sea level) - is located in the Blue Ridge region. Springer Mountain (3782 feet) marks the beginning (of the southern end) of the famous Appalachian Trail.
