mother rock

mother rock

[′məth·ər ‚räk]
(geology)
References in periodicals archive ?
Decomposed granite can be found in nature and the impurities in the mother rock can add colour to the blemishes.
A quarter of a kilogram, hewn from Mother Rock 70017 in 1972, was split into 1.
We came to a short hill, and after we had reached the top we saw a group of white farm buildings, built just off the road, in the mother rock of the hill.
Then too you will be interested to know that there are many glacial boulders on the island and shore, of a granitic structure similar to the granite of Scotland, so it looks as if they were brought by the ice during the Glacial epoch from their mother rock away off to the northwest in Scotland.