A finer-grained material making up the main body of a rock, in which larger units appear. Related Articles: Urban geology: Two granitesGlossary: AgglomeratesGlossary: LatiteThe Deccan Traps, India (Part 2): Its geomorphology and stratigraphyThe Deccan Traps, India (Part 3): Evidence of recent tectonic activities in Deccan basalts« Back to Glossary Index