Tripod Rock is a glacial erratic,[1] in this specific case a balancing rock,[2] or perched boulder, located in Kinnelon, New Jersey in the Pyramid Mountain Natural Historic Area. This multi-ton Precambrian gneiss boulder, located near the edge of a long ridge, is balanced on three smaller boulders. Tripod Rock is roughly 6 m (20 ft) long, 3 m (9.8 ft) wide, and 2.5 m (8 ft 2 in) high, weighing approximately 127 tonnes (280,000 lb). A triangular crest runs the length of its top. The boulder is balanced on three smaller stones roughly 1 m (3 ft 3 in) in diameter that raise it above the bedrock by about 0.5 m (1 ft 8 in) at its lowest point. The point of contact between the boulder and its support stones forms an approximate 3-4-5 triangle.
About 12 m (39 ft) northwest of Tripod Rock are three other boulders comprising a triangle. The two larger boulders are partially balanced on smaller stones (see diagram). The apex rock is about 3 m (9.8 ft) to the northeast. Two smaller perched boulders are located northeast of Tripod Rock (not shown on diagram) measuring approximately 1–3 m (3 ft 3 in – 9 ft 10 in) in diameter. No specific calendar alignment has been noted. Tripod Rock stands on a ridge overlooking a long valley where a massive glacial erratic named Bear Rock is located near a brook. Bear Rock was thoroughly excavated for archaeological artifacts during the 19th century, some of which are reported to be owned by museums.[citation needed] Bear Rock has a large overhang making it a possible rock shelter.
See also
editReferences
edit- ^ Becker, Martin A; Bartholomew, Alex (2013). "Lower Devonian glacial erratics from High Mountain, northern New Jersey, USA: Discovery, provenance, and significance". Atlantic Geology. 49: 194–203.
- ^ Volkert, R; Witte, R. "Geologic history and virtual field trip of the New Jersey Highlands". New Jersey Geological Survey.
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External links
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Media related to Tripod Rock (New Jersey) at Wikimedia Commons
- Pyramid Mountain Natural Historic Area official website, with trail maps and visitor information for the park that contains Tripod Rock
- Tripod Rock at New Jersey Skylands Visitor website
- Trail description at Trails.com
- Pyramid Mountain and Tripod Rock at City University of New York, Department of Geography