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A final climate consideration for outdoor travel is severe weather, especially tornadoes. In north and central Georgia, a tornado can strike anytime, but the greatest activity occurs from April to June.

Geology

The area of Georgia covered in this book includes four geologic zones: Valley and Ridge in northwest Georgia, the Blue Ridge in the northeast, Piedmont in the central area of the state, and the Fall Line separating the Piedmont from the Coastal Plain.

VALLEY AND RIDGE

As its name suggests, the Valley and Ridge area in northwest Georgia is comprised of a series of ridges and valleys that generally run from northeast to southwest. In the Paleozoic Era, this land was the bed of a shallow sea, and the landscape is comprised of limestone, sandstone, shale, and coal. Near the end of the Paleozoic Era, two tectonic plates collided, and metamorphic rock was pushed up and over sedimentary stone in northwest Georgia. This process bent the land into large folds, and a ripple effect to the northeast formed the Appalachian Mountains. Over time, erosion created what we see today—long ridges covered mostly with pine and oak forest and valleys between that serve as pastureland and farm fields.