But the walls were admitting a fragmental echo of what must have been a reverberating voice.
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.
Clastic, klas′tik, adj. breaking into fragments, fragmental.
The rocks, so far as I saw them, are massive lavas, and not fragmental scori or other products of explosive eruptions.
Hence the form or outline of many of these fragmental craters is crescent-shaped.
Ancient tuffs are known by the fragmental character of their volcanic material, even though they have been altered to firm rock.
The result is the production of huge amounts of fragmental volcanic debris.
The cone-building stage may be said to continue until eruptions of lava and fragmental materials cease altogether.