651-4047-00L  Microscopy of Magmatic Rocks

SemesterAutumn Semester 2016
LecturersP. Ulmer
Periodicityyearly recurring course
Language of instructionEnglish


AbstractThis course provides basic knowledge in microscopy of igneous rocks. Apart from the identification of common igneous minerals in thin sections, mineral assemblages, textures and structures will be investigated and the results of microscopy will be combined with igneous phase equilibria to understand generation, differentiation and emplacement of igneous rocks.
ObjectiveThe principal goal of this course is to acquire expertise in :
(1) optical determination of minerals in igneous rocks using the polarizing microscope
(2) Identification of igneous rocks basing on modal mineralogy, structure and texture;
(3) Interpretation of textures and structures and associated igneous processes;
(4) Application of igneous phase diagrams to natural rocks.
ContentThis practical course bases on the course 'Microscopy of metamorphic rocks' (P. Nievergelt), that is taught immediately before this course, where basic knowledge in optical mineralogy and the use of the polarizing microscope is acquired.
In this course, the most important (common) igneous minerals and rocks are studied in thin sections under the polarizing microscope. Mineral assemblages, structures, textures and crystallization sequences are determined and utilized to understand the generation, differentiation and emplacement of igneous rocks. In addition, we will apply igneous phase equilibria that have been introduced in other lectures (such as magmatism and volcanism at ETH/Uni Zurich or an equivalent igneous petrology course) to natural rock samples in order to constrain qualitatively parental magma compositions and crystallization conditions.
The range of investigated rocks encompasses mantle rocks, tholeiitic, calc-alkaline and alkaline plutonic and volcanic rocks that contain the most common igneous minerals.
Lecture notesBasis of the optical determinations of (igneous) minerals using the polarizing microscope are the tables of Tröger ('Optische Bestimmung der gesteinsbildenden Minerale', Optical determination of rock-forming minerals, 1982) that are available in sufficient volumes in the class room.
Some loose sheets will be distributed during the lecture providing additional information and templates for thin section descriptions.
Additionally, I recommend the lecture notes of H.-G- Stosch (University of Karlsruhe, in German) that can be provided in printed form upon request.
LiteratureThere are several good textbooks on the subject of ´mineralogy in thin sections´ that I can suggest upon request.
Prerequisites / NoticeThis course does not include an introduction in optical mineralogy and the use of a polarizing microscope and, therefore, bases on the course ¨Microscopy of metamorphic rocks¨ taught by P. Nievergelt immediately before this course where these basic principles are provided. Alternatively, e.g. for external students, an equivalent course is required to follow this practical course.

Other microscope courses taught at ETH Zurich at the D-ERDW are:
Microscopy of metamorphic rocks (P. Nievergelt, required for this course)
Microscopy of sedimentary rocks (W. Winkler & Blaesi)
Reflected light microscopy and ore deposits practical (T. Driesner)
Microstructures (deformation structures, B. Cordnonnier)