Tripod Rock

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.

References

^ 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. {{cite web}}: Missing or empty |url= (help)

External links

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

40°57′41″N 74°23′06″W / 40.9613°N 74.385°W / 40.9613; -74.385

[Becker-1] 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.

[2] Volkert, R; Witte, R. "Geologic history and virtual field trip of the New Jersey Highlands". New Jersey Geological Survey. {{cite web}}: Missing or empty |url= (help)

[1]

[2]