noun which may take the genitive case particle 'no'
basaltic
Geological term used to describe rocks, lava, or terrain composed of or resembling basalt.
See also: 玄武岩 (げんぶがん)
Basaltic lava flows spread across this region.
Basaltic magma has relatively high fluidity.
玄武岩 is the noun 'basalt', while 玄武岩質 is the no-adjective meaning 'basaltic'.
Compound of 玄武岩 (basalt) + 質 (quality, nature), literally 'of basalt nature'.