Explore the many rocks of the central Pa. region with Centred Outdoors
Five hundred million years ago, the geology and life forms on Earth and in present-day Pennsylvania were nothing like they are today. Complex life did not exist, and the small amounts of algae that were present could not prevent erosion like plants that hold together rocks and soil can. As a result, during the rainfalls of this time, huge swaths of sediment were frequently washed down rivers and across wide, flat river deltas.
These deltas existed in the area we now call Pennsylvania. Tiny silica particles in the deltas slowly accumulated and were eventually pressed into some of the strongest rock in the world by the weight of the above layers. These are the rocks that form our mountains today and are widely classified as siliciclastic, meaning made mostly out of silica. This classification is in the same groups as quartz, and indeed many of the rocks in our region contain small quartz inclusions.
A series of massive collisions between the areas that would become North America, Europe and north Africa pressed these layers into a jumble. Fascinating geologic features slowly began to rise from the previously smooth surface. Unlike in other mountainous areas however, the mountains were not pushed up from below. Instead the rocks folded like wrinkles forming on a blanket. These wrinkles ended up becoming the Proto-Appalachian Mountains, whose peaks rivaled that of the modern-day Himalayas.
Eventually the other continental plates shifted and began to move apart, creating the Atlantic Ocean and leaving mountains behind. The mountains began eroding, and as the hard outer layers of the mountains cracked, softer layers of inner limestone were revealed. The cores of these gargantuan hills washed away to form much of the east coast, leaving behind just the roots of the old mountains.
The massive parallel mountains presented many challenges to early native people, and eventually to European settlers during their colonization efforts. While settlements quickly spread across areas with large placid rivers or coastal seaways, the heart of Pennsylvania remained mostly untouched wilderness until the late 1700s when people finally began flocking to the wide, fertile valleys.
There are fascinating geologic formations across our entire region, but here are some of the best places to experience some of the more prominent features during your next outdoor adventure.
Hiking along the Lower Trail gives a glimpse into the incredible power water has to shape our landscape. The adjacent Juniata River has spent tens-of-millions of years carving its way through that tough silica-based rock, leaving behind a meandering path. Nearby, roadway cuts into the mountain give a clear sight into the intricate folds and faults that make up the layers of stone. The 17-mile trail runs between an area near Canoe Creek State Park in Blair County to near Alexandria in Huntingdon County.
Mount Nittany in Lemont is a prominent landmark that just so happens to be a perfect example of the inverted geography. When making the trek to the top, people often become puzzled as to why there is so much sand at the top. The top of Mount Nittany is the original bottom of the rivers that eroded the first peaks of the Appalachians. The parking area to Mount Nittany can become congested on weekends, especially when the weather is beautiful, so consider hiking early or during business hours to avoid crowded trails.
A trip to Poe Paddy State Park near Millheim gives guests the opportunity to not only hike on the ancient rocks, but also to go through them via the Poe Paddy Tunnel. After passing through the tunnel, the Mid State Trail continues past a series of large boulder fields that are the collapsed slopes of mountains. Here guests can see the effect the fast eroding materials have on the stronger ones that lay above them.
The Scotia Barrens, aka State Game Lands 176 in Warriors Mark, is a unique geologic destination because of the features it possesses that are beneath your feet. The underlying limestone is so porous, and the soil is so well drained that surface water features are almost nonexistent here. The water that falls in this area quickly enters the ground and makes an incredible subterranean journey before emerging well-filtered and chilled at several springs feeding into Spring Creek, including Big Spring in downtown Bellefonte.
The Spring Creek Canyon, as the name implies, is a gorgeous feature carved out by the waters of Spring Creek. At the southwest trailhead on Rock Road in Benner Township, the many layers of limestone and shale that form the valley floors are exposed and readily observed. Trails along the Spring Creek Canyon can also be accessed via the Fisherman’s Paradise parking lot located off Spring Creek Road in Bellefonte, and from the Shiloh Road exit off 322 in State College.