fragmental

Fragmental rocks are often quite indurated—the matrix being as hard as the included stones.

When a fragmental rock is composed chiefly of rocks belonging to the acidic group, we say it is felspathic.

These are overlaid by a series of alternating beds of crystalline (c) and fragmental (t) igneous rocks.

The rocks, so far as I saw them, are massive lavas, and not fragmental scori or other products of explosive eruptions.

The cone-building stage may be said to continue until eruptions of lava and fragmental materials cease altogether.