GPHY 102 Lecture Notes - Lecture 12: Geologic Time Scale, Siltstone, Gneiss

• School: Queen's University
• Department: Geography
• Course: GPHY 102
• Professor: Ryan K Danby

Document Summary

Gphy102 lecture 12 earth materials and the rock cycles. Bulk composition of the crust: 47% oxygen, 28% silicon, 8. 1% aluminum, 5. 0% iron, also <4% made up of calcium, sodium, potassium, magnesium and others. Minerals: crustal elements frequently bond with each other to form minerals. Posses specific chemical composition and physical properties. Frequently has crystalline structure: distinguished from each other by their: Color: comprised of mineral assemblages in a solid state, most rocks contain several minerals, many different rock types, generally three-type classification. Igneous rocks: solidified from minerals in a molten state. Formed from lava as same composition as gabbro. Sedimentary rocks: formed from layered accumulations of mineral particles which are derived (mostly) from weathering and erosion, transformed into rock via chemical, physical and biological processes collectively called diagenesis. Original materials transformed into new form: cover about 75% of earths surface, but only 5% of rock mass. Cover igneous and metamorphic rocks: classified based on type of sediment and their formation.