wall rock

American  

noun

Mining.

1. the rock forming the walls of a vein.

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wall rock British  

noun

1. rock that is immediately adjacent to a mineral vein, fault, or igneous intrusion

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Etymology

Origin of wall rock

An Americanism dating back to 1855–60

Example Sentences

“They were pioneering techniques that didn’t exist at the time. They were kind of inventing the sport of big wall rock climbing,“ said Daniel Duane, author of “El Capitan: Historic Feats and Radical Routes.”

From Seattle Times

"The passengers are solid chunks of wall rocks that carry a wealth of details on conditions far beneath the surface of our planet over time."

From BBC

All I could make out was the endless ramp, the wall rock, thick cables bolted to the granite, looping on ahead until they disappeared where the headlights lost themselves in the dark air.

From The Wall Street Journal

I could soon talk glibly of "blossom rock," "pay streaks," "cap rock," "wall rock," "rich color," and use the common terms of miners.

From Project Gutenberg

They also replace the wall rocks; limestone is especially susceptible.

From Project Gutenberg