Metamorphosed Basalt

This rock is part of a 1,000-cu-km (240-cu-mi) lava flow -- one of Earth's largest. It solidified from basaltic magma that erupted during rifting 1.1 billion years ago.

Mineralized Basalt

This mineralized basalt was metamorphosed by hot water near a black smoker. Hole 504B: 83-504B-80-1. 106-120 cm, #7B