Greenstone belts are generally elongate, Archean to Proterozoic terrains comprising intrusive and extrusive mafic to ultramafic igneous rocks, felsic volcanics, and inter-flow or cover sedimentary rocks. Greenstone belts occur sandwiched between regions dominated by granitoids and gneiss. Greenstones are generally of low to moderate metamorphic grade. The term greenstone comes from the green color of many mafic to ultramafic constituents due to an abundance of chlorite. A common igneous rock in greenstones is komatiite. Komatiites are rocks with greater than 18 weight percent magnesium oxide and a well-developed spinifex texture of inter-locking bladed or acicular (pointed) crystals of olivine or pyroxene. Spinifex texture (named after similarities in crystal shape and pattern to the pointed spinifex grass that grows in South Africa and Western Australia) implies rapid cooling or decompression of the magma. Komatiites formed as volcanic flows and less commonly as intrusive sills. Sedimentary sequences within greenstone...