Why would the crystals in an intrusive igneous rock be larger than the crystals in a chemical sedimentary rock?

1 Answer
Feb 21, 2016

sedimentary rocks have smaller crystals because they have been weathered and eroded away from parent rock


sedimentary rocks are formed on surface of earth by sediments of other rocks or by chemical formation of rocks. intrusive igneous rocks are made in sub-surface of earth where the temperature and pressure conditions are high. the crystals of intrusive igneous rock are big because they have been given more time to grow and no external processes like weathering and erosion are acting on it. but in sedimentary rocks they crystals are actually the weathered pieces of other rocks