Geology of Ruffner

Red Mountain forms the backbone of the Ruffner Mountain Nature Preserve. The mountain and its adjacent valleys lie within a portion of the Valley and Ridge physiographic province. This province extends from central Alabama to New York and is known for its elongated ridges and valleys. Its origins date back 300 million years to the growth of the Southern Appalachian Mountains in the Pennsylvanian geologic period.

The mountains arose as the North American, South American, and African continents slowly collided over the span of 50 million years. The collision caused the earth’s crust to buckle and fault. Massive sections of crust were folded or thrust up and over one another. The distorted landscape became the Valley and Ridge province. A more detailed overview of the region’s geology can be found here.

Red Mountain is all that is left of a huge folded section of crust that once spanned the valley in which Birmingham was founded. The mountain’s folded and fractured rock eroded away over the past 250 million years. Red Mountain and a parallel line of hills to the north are all that remain. Jones Valley, where Birmingham was founded, is the low area between these ridges.

At Ruffner Mountain Nature Preserve there are several types of rocks left exposed at the surface as the original mountain eroded away. Two of these rocks – limestone and hematite, also known as iron ore, – were key ingredients for Birmingham’s iron industry and the city’s creation. A detailed description of Ruffner Mountain Nature Center’s rock types can be found here.

Red Mountain’s geologic complexity also means that this park offers a range of topography to explore, from the highest peak, which is 1,246 feet above sea level, to the quarries and mines offering a glimpse of the mountain’s rocky interior. Stand on the edge of the crater-like limestone quarries for sweeping views of the mountain, the forest, and the city below. From Hawk’s View Overlook or the Cambrian Overlook you can see over 20 miles away.

The geologic complexity of Ruffner Mountain Nature Preserve provides numerous ecosystems to explore. This includes small caves and sinkholes in the limestone where salamanders and roosting bats may be found. A low ridge of the Hartselle Sandstone to the south of Red Mountain provides acidic soils and the remnants of Longleaf and Shortleaf Pine woodlands. Alkaline soils on the northern slope of Red Mountain are the foundation for lush moist forests.