The only show cave known to boast a Palaeozoic reef. (July 2017)

• Record Type: Journal Article
• Authors: Painter, Deborah
• Is Part Of: Geology today. Volume 33:Number 4(2017)
• Page Start: 138
• Page End: 141
• Publication Date: 2017-07
• Subjects: Geology -- Periodicals; 551
• DOI: 10.1111/gto.12191
• Languages: English
• ISSNs: 0266-6979

Abstract

Abstract : In south‐central Pennsylvania, USA, is the world's only Upper Silurian/lower Devonian period shallow water marine reef, located deep within a cave and operated for the tourist trade. Other unusual features in the cave include black basaltic rock, the presence of nearly perfect clear calcite crystals and varied cave decorations. The reef is primarily composed of stromatoporoids with brachiopods and crinoids and is part of the Upper Silurian Jersey Shore Member of the Keyser Formation siliciclastics and carbonates. Just outside the cave itself is a transition to the Devonian New Creek and Corriganville formations, also siliciclastics and carbonates. In these formations are the only actual fossil corals in the vicinity of the cave discovered by Boy Scouts in 1928 by climbing through a natural entrance. 'Wonderland Coral Caverns' was opened to the public in the 1930s and closed in the 1980s until a safer entrance could be created. The cave is the result of the Alleghanian Orogeny in which Silurian and Devonian sedimentary strata were buried without metamorphism beneath the encroaching northwest African continental mass as the proto‐Atlantic Ocean and the Rheic Ocean closed. The mass eroded completely and the resulting sediments were transported to the west of modern day Pennsylvania, leaving a karst topography and a well preserved fossil reef.