A large body of magmatic material that cools in the deeper depth of the Earth’s crust and develops in the form of large domes is known as

The correct answer is A, Batholiths. A batholith is a huge mass of magma that cools and hardens deep inside the crust, usually as granite, and takes the form of large domes.

When magma does not reach the surface, it solidifies underground and forms intrusive igneous landforms. Batholiths are the biggest of these, often covering hundreds of square kilometres and forming the cores of mountain ranges. They are exposed only when the rocks above are worn away by erosion. Because they cool slowly at great depth, their rocks have large crystals. Smaller intrusive forms are named by their shape: sills and dykes are sheets lying along or across rock layers, while laccoliths, lopoliths and phacoliths are lens- or saucer-shaped bodies at shallower depths.

B is wrong because a laccolith is a smaller mushroom-shaped body that pushes up the rock layers above it, with a pipe below feeding it. C is wrong because a lopolith is a saucer-shaped body that sags downward. D is wrong because a phacolith is a wavy, lens-shaped mass found at the crests and troughs of folds.

Exam tip: batholith = large deep granite dome; laccolith = dome on a pipe; lopolith = saucer; phacolith = wavy lens in folds.