The Idol Rock
Brimham’s most remarkable rock
The power of the wind
The effects of wind erosion, combined with thaw-freezing cycles and rock layers with different ratios of hard and soft components, have created one of the most remarkable rocks on the site.
The differing effects of wind, sandblasting and rock components lead to the maximum erosion at the base of the rock whilst higher up the harder layers resist erosion.
The explanation of why the sandblasting effect greater nearer to the ground is because the grains of sand that have been eroded off the Millstone Grit are heavy and will not lifted high by the wind.
How big and how heavy is the Idol Rock?
The Idol Rock weighs in the region of 188,000 kilos, about 185 tons, and this rests on a base that is only a quarter of a square metre in area.
The pressure on the base is enormous, approximately 751,000 kilos per square metre, and this has profound effects on the resistance of the base to erosion.
