basalt

Somewhere in the basalt hills a lion roared, the sound carrying through the night until another responded.

Here there are many craters and much basalt, or even lava; also hot springs.

The whole is built of basalt with yellow marble columns, and yellow marble bands here and there.

They had also said something about pot holes like shafts in the basalt.

Then she rose up and passing amongst them as a friend amongst friends came towards the caves in the basalt cliffs.

There was no getting round that drop, it was a basalt step that circled the whole Lizard Point on its seaward side.