Authorised by Academic Registrar, April 1996
Objectives On the completion of this subject students will be able to characterise the external form of crystals from the various crystal systems and be able to identify minerals in hand specimen; understand the structural controls on the chemistry of minerals; understand the operation of the petrographic microscope and mineral identification in thin section; describe and classify the common igneous and metamorphic rock types in hand specimen and thin section; understand the behaviour of major and trace elements in natural magmas as a function of magmatic processes; describe the relationships between distinctive mineral assemblages and physical/chemical variables during metamorphism
Synopsis This subject consists of two units, each six weeks long, both compulsory. (1) Crystallography, optics and mineralogy. External form of crystals; crystal systems; stereographic projection in crystallography; packing of atoms and ions in crystals; structural controls on the chemistry of minerals. Transmission of light by crystals; the polarising microscope; optical properties of common minerals and mineral identification. Structure and chemical compositions of common mineral groups; properties of minerals. (2) Igneous and metamorphic geology. Chemistry of common igneous rock groups and their parental magmas. Behaviour of major and trace elements during crystallisation of natural magmas and simple analogues. Development of characteristic mineral assemblages and textures during igneous crystallisation and metamorphism. Relationships between distinctive mineral assemblages and physical and chemical variables during metamorphism.
Assessment Examinations (4 hours): 65% + Practical work/fieldwork: 35%