REMARKS: Large, highly visible outcrops of light-gray quartzite (Weverton Formation, Early Cambrian age) near the summit give this feature its name. Browns Spring (303) is at the base of the mountain.
REMARKS: Weathered outcrops of moderately dipping quartzite (Antietam Formation, Lower Cambrian age) form Eagle Rock. This west rim of South Mountain and discontinuous ridges and knobs are part of a broad symmetric arch (anticline) in this corner of Franklin County.
REFERENCES: Fauth, J. L. (1968), Geology of the Caledonia Park quadrangle area, South Mountain, Pennsylvania, Pennsylvania Geological Survey, 4th ser., Atlas 129a, p. 116.
REMARKS: An outstanding overview from spectacular pinnacles of Weverton quartzite (Cambrian age). Stretched pebbles and crossbedding may be seen in the rocks, which are located approximately 650 feet from the road and Appalachian Trail. Chimney Rocks (311) and Buzzard Peak (312) are visible in the distance.
REMARKS: Erosion by two streams through Front Mountain has produced a broad, flat gap sloping gently on both sides and resembling a saddle in shape. Local folklore says it resembles a young lady lying on her back with her legs outstretched; hence the name, Nancys Saddle.
Both Parnell Knob (247), 5.5 miles to the southwest on Front Mountain in St. Thomas Township, and Nancys Saddle are erosional features sculptured from the hard, dense Tuscarora quartzite (Silurian age).
During the Civil War, Nancys Saddle provided a passageway from the Cumberland Valley to a large intermountain valley to the west. Yankee soldiers used this passageway to the mountain valley to hide their stock of horses. Later the valley became known as Horse Valley.
REFERENCES: XXX
REMARKS: Soft, easily weathered shales (Ordovician age) in the center of a south-plunging anticline have been eroded to expose a large amphitheater-like feature (called "The Punchbowl") surrounded by high ridges of hard, resistant quartzite (Tuscarora Formation, Silurian age).
REMARKS: A breathtaking view (west) from atop Tuscarora Mountain; elevation 2123 feet. The Tuscarora quartzite (Silurian age) underlies the summit and, due to its hardness and extreme resistance to weathering, is responsible for the high mountain. Cape Horn (287), on the south side of the highway at the parking area, provides an excellent view to the north.
REMARKS: Towering spires of white quartzite (Antietam Formation, Early Cambrian age) on the west face of the Montalto Mountain are visible for miles. The almost verticle dip of the rocks, combined with a wide spacing of joint fractures, has resulted in huge, vertical columns of quartzite; through weathering, these columns have attained their present shapes. Eagle Rock (319) to the south is a similar geologic feature. Springs, such as Chestnut Spring (320) and Pearl Spring (321), are common at the base of the mountain.
REFERENCES: Root, S. I. (1968), Geology and mineral resources of southeastern Franklin County, Pennsylvania, Pennsylvania Geological Survey, 4th ser., Atlas 119cd, 118 p.