basaltic

basaltti- Of or pertaining to basalt.
1894, Ivan Dexter, Talmud: A Strange Narrative of Central Australia, published in serial form in Port Adelaide News and Lefevres Peninsula Advertiser'' (SA), Chapter I, http://gutenberg.net.au/ebooks16/1600641.txt

Even the beneficient rainfall had failed to attract animal life to the basaltic waste, and the genius of silence seemed to brood over all.

The island gains its geothermal heat from basaltic magma in the fissure systems of the Mid-Atlantic Ridge.