Introduction

Basalt is the most abundant rock on Earth. It forms the ocean ridges, slides off onto the ocean floor, and eventually dives back down. Basalt is the lava which pours out of Kilauea in Hawaii, and maybe crosses a tar road without melting it (we love to play that ace). Basalt is the rock that formed the island of Surtsey, off Iceland, as people watched. It springs up here and there on continents (Japan, USA in Washington or New York). The name is applied to the solid rock, the lava, and to the magma which, on eruption, becomes lava.