GEO E111 Lecture Notes - Lecture 30: Silicate Minerals, Talc, Basalt
Document Summary
Inorganic substances occurring naturally at or below the earth"s surface. Ferrous minerals - limonite, magnetite, siderite and haematite. Non-ferrous minerals - copper, aluminium, gold, lead, etc. Non-metallic minerals - graphite, diamond, asbestos, coal, etc. A consolidated material composed of grains of one or more minerals. Rocks formed when molten material from the earth"s interior cools and solidifies on or beneath the earth"s surface. Types of igneous rocks a) intrusive igneous rocks. Rocks formed when magma cools and solidifies below the earth"s surface e. g. granite, diorite, gabbro, peridotite. Have coarse texture as a result of slow cooling giving minerals more time to form large crystals. Are classified further into two: (i) hypabyssal rocks - intrusive igneous rocks which are near the earth"s surface. (ii) plutonic rocks. Intrusive igneous rocks which are deep below the surface: extrusive igneous rocks. Rocks formed when lava solidifies on the earth"s surface.
