Petrology I 1300-OPT3W

The purpose of the lectures on igneous petrology depicts geochemical modeling of igneous processes; the modeling of various petrogenetic mechanisms which it is possible to reconstruct on the basis of examination of igneous rocks. They include: melting and crystallization, magma mixing, contamination, and metasomatism. First, the processes and the possibilities of their identification by microscopic observations are presented. Then, the identified processes are modeled using geochemical databases and available software. The lecture is mostly interactive. The students participate in discussions on each stage of the identification of the processes and they attempt to model the processes themselves.
During the lecture on sedimentary petrology the following issues are discussed in detail:
• Formation of sedimentary rocks in various environments and climatic settings.
• Minerals indicative of various environments and climatic conditions.
• Provenance of detrital material; reconstructing the transport directions and the potential source areas.
• Transport and sedimentation of detrital material; analysis of various sedimentary environments, criteria for differentiating between sediments deposited in aqueous and in aeolian/eolian environments.
• Diagenesis of clastic, carbonate, and clayey rocks – types of diagenetic processes and their pathways, textures and minerals characteristic of different diagenetic stages.
• Applications of petrological reconstructions in geology: e.g. palaeogeographic, palaeoecologic, palaeoclimatic reconstructions.
•Practical use of sedimentary rocks.
The lectures devoted to metamorphic petrology aim at comprehensive presentation of issues related to the formation of metamorphic rocks, their differentiation in relation to the pressure-temperature conditions, the chemical composition of the rocks and the resultant textures. It explains how important information recorded in a rock, such as the temperature and pressure of formation, direction, style, conditions, and age of deformation, can be deciphered. Different kinds of metamorphism are characterized and compared. Students become familiar with the range and conditions of activity of metamorphic processes, with the equilibrium associations being formed in different environments (depending on the chemical composition of the protolith). In particular, the metamorphism of pelitic, basic, carbonate, and ultramaphic rocks is presented. The following types of metamorphism are explained in detail: Barrow and Buchan type regional metamorphism, high-pressure regional metamorphism typical of subduction zones, contact metamorphism of different facies, dynamic, impact, sea-floor, and hydrothermal metamorphism. Students are taught how information on phase equilibria are depicted on tenary compositional diagrams (ACF, AFM, SCM, and others), about the ways of reconstructing P-T-t conditions (pressure-temperature-time) using the so-called geological thermometers, barometers, and chronometers. The results of the lectures depend on the time spent by the students at the microscope. The estimated minimum time necessary to maximise the results of the teaching is around 100 hours.
Classes on igneous petrology are devoted to recognition of rock forming minerals of igneous rocks Students perform detailed analyses of textures and relationships between rock-forming minerals in thin sections. The aim of this is to reconstruct P-T conditions of magma generation and the following evolution of magma from which the rock was formed.
Classes on sedimentary petrology consist of individual work with the use of a polarizing microscope. Students examine thin sections of the main types of sedimentary rocks: clastic, carbonate, siliceous, They are taught how to make a full description of a sedimentary rock based on the determination of its mineral composition and texture which is necessary for proper recognition and classification. Students learn to recognize the effects of the primary processes which led to the formation of the rocks and to interpret their sedimentary environments. Moreover, students familiarize themselves with techniques used for identifying secondary alteration so that they are capable of reconstructing the diagenetic histories of these rocks.
Classes on metamorphic petrology are also taught in the microscope lab, where rock samples in the form of thin sections are observed in polarized light. This method allows the students to develop their skills in identifying minerals and rocks typical of metamorphic conditions. They learn to describe rocks: to determine their mineral composition, texture, characteristic mineral parageneses defining their genetic conditions, to select material for further studies, and to draw conclusions concerning the genesis of these rocks.