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Staff involved: Dr Geoffrey Clarke and Prof. Bas Hensen.
Module Objectives: his sub-module will introduce how whole rock and mineral geochemical data may be used to quantitatively constrain the P-T-X conditions that formed some common metamorphic rocks, and the application of phase diagrams to common metamorphic problems. We will cover elementary thermodyamic theory, concentrate on the use of data that has already been aquired via electron microprobe analysis of rock thin sections, and the principles of Schreinemakers analysis. At the end of the course you should have sufficient knowledge of, and confidence in, thermobarometric and phase diagram methods to (1) competently analyse a given metamorphic rock; (2) describe the minerals present in terms of their composition and potential end-members; (3) apply common, experimentally calibrated thermometers and barometers; and (4) construct simple phase diagrams that complement quantiative methods of analysis. Since the conditions of formation of many common mineral assemblages may not be precisely defined, a thermobarometric method that uses an approach involving an internally consistent thermodynamic dataset will also be introduced and applied.
Module program: Following introductory lectures, you will complete tasks that involve the calculation of mineral end-member concentration in minerals that show ideal and non-ideal solid solution, calculate P-T conditions for some common mineral assemblages using experimentally calibrated thermometers and barometers and the average PT method using an internally consistent thermodynamic dataset. Topic dealing with schreinemakers analysis will address the information recorded by mineral corona reaction textures in granulite facies rocks. Morning lecture sessions cover theories that will be used in completing related problems in the afternoon of each day. You should complete most tasks using Excel spreadsheets; this is the easiest way in most cases and will teach you how to use that software. Some course notes will be provided as a guide only; they vary in detail and for parts of the lectures you will need to take notes.
Format, duration and timing: Lectures and practical sessions. Lectures/tutorial discussions; computer practicals; computer demonstrations. Not offered in 2004.
Assumed Knowledge: Third year metamorphic petrology or geochemistry.
Text and/or reference material:Recommended general references:
Wood, B.J. & Fraser, D.G., 1976. Elementary thermodynamics for geologists. Oxford University Press, 303pp
Assessment: Practical assignment.
Module contact person and coordinator: