Igneous Rocks: Formation, Composition, Naming

Igneous rocks crystallize from molten silicate material called magma that forms at high temperatures and pressures deep in the Earth. Magma rises through the crust and either reaches the surface by volcanoes (extrusive) or cools below surface (intrusive). How Magmas Evolve – according to Bowen’s Reaction Series: discontinuous (different molecular structures of olivine [single tetrahedra],…

How Rocks Form: Igneous Rocks, Sedimentary Rocks, Metamorphic Rocks

Why Study Rocks? -Many, many uses! – writing tools (chalk, pencils), building materials (marble, concrete), fuels (coal), scouring powder (pumice, sand), weapons (flint, obsidian) Rock: a group of minerals bound together –  Found in the Earth’s crust and mantle The Rock Cycle: the continuous process of rock formation and change – Presents a “map” of the…