REMARKS: This is one of the world's largest known potholes, formed by swirling meltwater during the retreat of the Wisconsinan ice sheet, it is 38 feet deep and 42 feet in diameter.
REFERENCES: McGlade, W. G. [1969], Archbald Pothole State Park: Archbald Pothole, Pennsylvania Geological Survey, 4th ser., Park Guide 3.
REMARKS: A magnificent gorge and waterfalls on Roaring Brook, which passes through Nay Aug Park. Dark-gray to black shales and siltstones of the Llewellyn Formation (Pennsylvania age) are exposed in the walls of the 75-foot-deep gorge. The park is also the site of the Brooks mine, the only model coal mine in Pennsylvania.
REMARKS: An outcrop of Catskill conglomerate (Devonian age) forms a prominent outcrop; a first-order triangulation station marker is located in the rock. From "Pinnacle Rock" the northernmost extension of this province can be seen. Mountain ridges common to this section are less distinct here, and the topography tends to blend with that of the Glaciated Low Plateaus section of the Appalachian Plateaus province.
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