Experimental Methods in Petrology

Abstract

Overview of the most common experimental methods employed in petrology to determine thermodynamic and physical properties and phase equilibria of minerals, mineral assemblages, magmas and fluids. The basic principals of low, moderate, high and ultrahigh pressure devices are discussed combined with an introduction into the synthesis of starting materials and the evaluation of run products.

Objective

This course shall provide the basics of experimental petrology. The principal goals are the acquisition of basic knowledge about experimental equipment employed in petrology and the design and setup of an experimental study targeted to obtain quantitative data on phase relations, thermodynamic, kinetic and rheologic properties of earth materials as well as the examination, analysis and evaluation of experiments. At the end of the course, the participants should be able to evaluate experimental data independently and design appropriate experiments on their own.

Content

The course 'Experimental methods in petrology' covers the following subjects: (1) Introduction and historical summary of experimental petrology (2) Experimental methods at ambient pressure (1 bar) with practical exercise to determine the free energy of formation of wustite (FeO) (3) Experimental buffering techniques (phase rule, buffering of partial pressures of gases and supercritical fluids, buffering of mixed volatile phases at elevated pressures, buffering of activities and solid-solid solutions in solid phases. (4) High-pressure solid-media experimental techniques (piston cylinders) (5) Ultrahigh-pressure experimental techniques (multi-anvil apparatus, diamond-anvil-cells (DAC) (6) Evaluation of petrologic experiments (preparation of run products, analytical and spectroscopic methods of examination and quantification) Currently, a chapter covering hydrothermal (gas-pressure) experimental techniques is lacking and shall be included in the future (2009) The practical work in the laboratories are conducted (with the exception of exercise #1) on a small research project where the various techniques and equipment are demonstrated and the practical use is trained. This year (2008), the phase equilibria of the Pahoehoe lava-flow of the 1995 eruption of the Pico do Fogo (Cap Verde Islands) volcano are investigated at various pressures.

Resources