REMARKS: One of the best, if not the best, example of a tight anticline and syncline in the anthracite basin. These folds are located in, and are part of, the northern limb of the Western Middle Anthracite field; the Mammoth coal beds (no. 8 and no. 9) are involved in the folds.
REFERENCES: Arndt, H. H. [1971], Geologic map of the Ashland quadrangle, Columbia and Schuylkill Counties, Pennsylvania, U. S. Geological Survey Geologic Quadrangle Map GQ-918.
Haley, B. R., Arndt, H. H., Rothrock, H. E., and Wagner, H. C. [1953], Geology of anthracite in the western part of the Ashland quadrangle, Pennsylvania, U. S. Geological Survey Coal Investigations Map C-13.
REMARKS: An ancient meander of Roaring Creek has almost been cut off; only a thin sliver of land, Sharp Ridge (279) (Montour County), remains. Today Roaring Creek flows into the Susquehanna River at a different location, and the west half of the meander is a stagnant lake. Outcrops of red and green siltstones (Catskill Formation, Devonian age) are exposed on the crest of the ridge.
A vertical cliff of red and green shales and siltstones (Catskill Formation) is exposed beneath The Pinnacle, another narrow strip in a meander of Roaring Creek.