Advanced petrology

obligatory courses

Students should have the proper skills to handle the microscope and to recognize rock-forming minerals and rocks before they start the “Petrology II” subject. Therefore, they are advised to familiarize themselves with the following subjects and issues:

Mineralogy – properties of rock-forming minerals.

Dynamic geology – geotectonics, processes forming igneous, sedimentary and metamorphic rocks, igneous and post-igneous processes, sedimentary environments.

Petrology – recognizing rock-forming minerals with the use polarizing microscope, recognizing main rock types.

Paleontology – recognizing fossils, habitat and age of main fossil groups.

Classes:

Classes on igneous petrology are devoted to an advanced recognition of igneous rocks and magmatic processes based on microanalysis. 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 following types of sedimentary rocks: clastic, carbonate, siliceous, iron-rich, phosphatic, organic-rich, and evaporite rocks. 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.

Specific themes taught during the classes on sedimentary petrology include:

• Methods of identifying minerals, mineraloids and other components of sedimentary rocks.

• Recognizing the effects of different secondary alterations (including diagenetic processes) with the use of analytical methods (polarizing microscope, scanning microscope, X-ray diffraction, cathodoluminescence, electron microprobe, etc.).

• Various types of cement and matrix.

• Microscopic techniques for identifying pyroclastic rocks.

• Analysis of heavy minerals – various methods for separating these minerals, preparing samples for microscopic observation, and identifying them.

• Investigating the effects of secondary alteration in sedimentary rocks used in the building industry and arts.

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.

1). After completing a part dedicated to metamorphic petrology students are able to recognize under the microscope constituents of the studied metamorphic rock (rock-forming minerals) both main and accessory (altogether a few dozens of minerals), to classify and name rocks on the basis of recognized mineral phases and using classification diagrams, to recognize metamorphic processes leading to the present rock state (reactions between the minerals, alterations, deformations), recognizing under the microscope main phases and textures describes metamorphic rock, approximately determine physical conditions of the rock formation using characteristic equilibrium assemblages.

2/3). The practical training in sedimentary petrology allow the students to acquire the necessary experience to recognize various sedimentary rock types and to interpret their formation, geotectonic settings, diagenetic evolution, provenance of clastic material, and potential practical use. These effects of teaching should be accomplished after the entire cycle of lectures (30 hours per semester) and classes (45 hours per semester).

4).Classes on igneous petrology are devoted to an advanced recognition of igneous rocks and magmatic processes based on microanalysis. 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.

1). Acquired skills are monitored during exercises by constant interaction between teacher and students. Final assesment of skills acquired during classes on metamorphic petrology is done by examination of thin sections under a polarizing microscope and describing mineral composition and texture, naming the rocks, assessing conditions of their formation, and identifying the effects of other important processes. Student activity during classes is also taken into account in the final marking. Indispensable condition for participation in this course is a passed exam of the subject Petrology I.

2/3). After classes on sedimentary petrology students are evaluated/rated on the basis of a colloquium consisting of the examination of thin sections and a full petrographic description of two different sedimentary rock samples. This description encompasses the determination of mineral composition, texture, rock type, precise classification, and naming of the rock. Then, students have to characterize processes of deposition and sedimentary environment. Moreover, they are to identify the effects of diagenesis and arrange them into a diagenetic sequence. Student activity during classes is also taken into account in the final marking.

4). Igneous petrology - credit points are given to a student on a basis of individual analysis of igneous processes as recognized in a thin section (microscopic identification of phase mineralogy, analysis of phase diagrams), as well as rock classification.

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