​Geol 244 Physical Earth Sciences and Structural Geology

Prof. Alex Kisters

Course Synopsis

This course is composed of two components

13375 244 - Physical Earth Science and Mapping (second semester, first term)

'There is no substitute for the geological map and section - absolutely none. There never was and there never will be. The basic geology still must come first - and if it is wrong, everything that follows will probably be wrong." (Wallace, 1975, Mining Engineering, vol. 27, 34-36) The 7-week course 'Physical Earth Science and mapping' (Geol. 244) is an introduction to the techniques of geological field mapping, map analysis and structural geology. Students will be introduced to the use of the geological compass, map symbols, the construction of topo- and structure contours, simple cross-sections and cross-section techniques, stereographic projection, interpretation of maps and aerial photographs. The emphasis of this course is on the practical aspects of geological mapping - although the module consists formally of 3 lectures and 1 practical per week, most lectures will involve practical work. The aim of the course is to enable the student to produce a geological map from the initial steps of data gathering in the field to the final product of a map, a section or a block diagram, that involves geological interpretation of the data. The course entails a 1-week field school at Laingsburg in the Cape Fold Belt (led by DeVille Wickens).

13374 244 - Introduction to Structural Geology (second semester, second term)

Structural geology is concerned with the deformation of rocks. A geological structure is a geometric feature in a rock whose shape, orientation and distribution can be described – this applies to almost any rock of whatever origin and illustrates the significance of structural geology in the Earth Sciences.

With this course, we attempt to integrate all scales of deformation and deformation processes. From atomic- and crystal-scale deformation mechanisms to deformation features in hand-specimen and outcrop which ultimately leads to an understanding of continental-scale deformation, or tectonic processes.

The basic principles of stress and strain are discussed, rheological models and factors that determine the rheological behaviour of rocks. Brittle deformation mechanisms and structures, ductile deformation mechanisms. Folds and fold-related structures, mechanics and kinematics of folds and boudinage. Types and styles of faulting, crustal deformation and faults, mechanics of faulting. Origin and significance of tectonic fabrics, planar and linear fabrics, their interpretation.

The aim of this course is to convey the common techniques, fundamental terminology and concepts of structural geology that allow the student to map, describe and interpret geological structures. Practicals are intended to apply the theoretical knowledge to geological problems and to develop a solid perspective on structural geology and deformation of rocks. Special field schools and excursions will be used to apply the structural knowledge to real rocks. A 1-week structural field mapping excercise in Bushmanland in the 3rd year will round this course off.