Tripod Rock

{{Short description|Balancing boulder in Kinnelon, New Jersey}}

File:A608, Tripod Rock, Pyramid Mountain Natural Historic Area, Morris County, New Jersey, United States, 2019.jpg)]]

File:3D Model of Tripod Rock.stl]]

Tripod Rock is a glacial erratic,{{cite journal |last1=Becker |first1=Martin A |last2=Bartholomew |first2=Alex |title=Lower Devonian glacial erratics from High Mountain, northern New Jersey, USA: Discovery, provenance, and significance |journal=Atlantic Geology |date=2013 |volume=49 |pages=194-203}} in this specific case a balancing rock,{{cite web |last1=Volkert |first1=R |last2=Witte |first2=R |title=Geologic history and virtual field trip of the New Jersey Highlands |publisher=New Jersey Geological Survey}} 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 {{cvt|6|m}} long, {{cvt|3|m}} wide, and {{cvt|2.5|m}} high, weighing approximately {{convert|127|tonnes|lb}}. A triangular crest runs the length of its top. The boulder is balanced on three smaller stones roughly {{cvt|1|m}} in diameter that raise it above the bedrock by about {{cvt|0.5|m}} at its lowest point. The point of contact between the boulder and its support stones forms an approximate 3-4-5 triangle.

About {{cvt|12|m}} 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 {{cvt|3|m}} to the northeast. Two smaller perched boulders are located northeast of Tripod Rock (not shown on diagram) measuring approximately {{cvt|1-3|m}} 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.{{cn|date=December 2021}} Bear Rock has a large overhang making it a possible rock shelter.