Examples from literature

• It was built upon a conical peak of basalt, and was surrounded by four deep valleys, one on each side, another in front, and the fourth in the rear. 
• The hills which bound the valley of the creek are basalt, sandstone, and schist. 
• The right bank of the river rose into steep cliffs of basalt, under which the clustered fig tree, with its dense foliage, formed a fine shady bower. 
• The soil is chiefly volcanic ash, disintegrated basalt and alluvium. 
• The spot was quite surrounded by high sloping walls of basalt, except to the west, where they opened in a three-foot cleft to the shore, and the ground was strewn with slabs and boulders of granite and basalt.