3.4.4 Igneous Textures: Glassy Texture Rocks, Obsidian from different magma compositions Granite and Basalt Glassy texture. During some volcanic eruptions, molten rock is ejected into the atmosphere where it is quenched quickly. Rapid cooling of this type may generate rocks …

3.4.4 Igneous Textures: Glassy Texture Rocks, Obsidian from different magma compositions Granite and Basalt Read more »

3.4.3 Igneous Textures: Porphyritic Rocks have Phenocrysts embedded in a Groundmass matrix What is Porphyritic texture? A large mass of magma located at depth may require tens to hundreds of thousands of years to solidify. Because different minerals crystallize at …

3.4.3 Igneous Textures: Porphyritic Rocks have Phenocrysts embedded in a Groundmass matrix Read more »

3.4.2 Igneous Rocks: Aphanitic Texture, Phaneritic Texture, and Vesicular Texture Aphanitic texture is fine grained. Igneous rocks that form at the surface or as small masses within the upper crust where cooling is relatively rapid possess a very fine-grained texture …

3.4.2 Igneous Rocks: Aphanitic Texture, Phaneritic Texture, and Vesicular Texture Read more »

3.4.1 Three Factors for Igneous Textures: Cooling Rate, Silica in the Magma, and Gases in the Magma The term texture, when applied to an igneous rock, is used to describe the overall appearance of the rock based on the size, …

3.4.1 Three Factors for Igneous Textures: Cooling Rate, Silica in the Magma, and Gases in the Magma Read more »