mining basalt rock locations
basalt mining regions. Basalt, NV · Dicalite Management Group. In the 1850s, mining began on stratiform native copper deposits in felsite-pebble conglomerates and in the upper zones of basalt lava flows (locally called amygdaloids).Although amygdaloid and conglomerate deposits tended to be lower-grade than the fissure deposits, they were much larger, and could be mined much …