A Geologist’s Dream: The Rock Behind Stone Mountain Park

Stone Mountain Park is every geologist’s dream due to its prehistoric history and is one of Georgia’s most popular places to visit. Children visit on school field trips to learn more about the rock behind Stone Mountain Park and its importance to the state of Georgia. Stone Mountain Park features 3,200 acres of preserved natural land, including oak and hickory forests, rocky terrain, lakes, streams, and waterfalls. In the center of it all stands Stone Mountain itself, which is what the park and the nearby city of Stone Mountain are named after. Stone Mountain has an elevation of more than 1,600 feet, and when you reach the summit, you will take in panoramic views that include the Atlanta skyline and the Appalachian Mountains.

Stone Mountain Is Made of More Than Granite

Many visitors to Stone Mountain are surprised to learn that this stunning dome is actually a large piece of granite. In fact, Stone Mountain is the largest piece of exposed granite in the world! Granite is an igneous rock that was formed millions of years ago in the magma near the Earth’s core. In fact, geologists have determined that the dome of Stone Mountain formed more than 300 million years ago, along with the formation of the Blue Ridge Mountains and the Appalachian Mountains.

As magma welled up below the Earth’s crust, it formed these large granite pieces that now make up the most well-known mountain ranges in the southeastern United States. As the magma cooled, it created this igneous rock with unique texture and composition. Stone Mountain is known as an inselberg or monadnock, which refers to a small mountain or rock hill that rose abruptly from an otherwise level surrounding area. That makes Stone Mountain Park particularly unique because it features relatively flat plains of forests, lakes, and lawns with a stunning dome in the center.

Rocks and Minerals Found at Stone Mountain Park

Stone Mountain is primarily known for its granite composition, though it is also comprised of quartz monzonite, and granodiorite. When you see a rock made of granite, you notice it has stark veins and granules are larger in size. Quartz monzonite is also lighter in color like granite and has a grainy, highly detailed composition. From afar, Stone Mountain looks solid gray, but when you get up close, you are able to see the exquisite detail of this incredible rock formation. A wide variety of minerals can be found in the rock at Stone Mountain Park, including quartz, microcline, and muscovite.

Natural and Geological History of Stone Mountain

Many visitors to Stone Mountain Park are surprised to realize just how many forests and trees surround the area and also occur on this rock dome. The lower slopes of Stone Mountain are home to Georgia oaks and pines, while the top of the mountain features a more bare rock landscape with rock pools. The summit of Stone Mountain is 1,686 feet above sea level and offers amazing views of the North Georgia Mountains and even downtown Atlanta. Visitors to Stone Mountain Park can get an up-close look at the composition of Stone Mountain by taking the Walk-Up Trail to the summit and back down! This trail is one mile long, and you will walk right up the mountain, passing rock formations, rock pools, indigenous trees, and views of forest all around. Visitors interested in a more challenging adventure will also appreciate the five-mile Cherokee Trail around the base of Stone Mountain with a dirt tread path and some steep sections as you actually hike up and over the west side of the mountain. This five-mile trail features views of Stone Mountain, lakes, streams, and forests full of oak and hickory.

Geologists and history buffs can learn more about the rock behind Stone Mountain and its history at the Quarry Exhibit at Stone Mountain Park. This exhibit and the many miles of trails inside Stone Mountain Park are free with your daily or annual parking pass.