Petrology I

obligatory courses

Petrology describes the genesis of three main rock types - igneous, metamorphic and sedimentary through the different processes leading to their formation. Petrology describes mineralogical composition and geochemical features of rocks as well as conditions of their formation. The subject is closely connected with geodynamics, structural geology (in particular with the plate tectonics), sedimentology (particulary analysis of sedimentary basins), geochemistry of igneous and metamorphic rocks and with mineralogy.

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.

to recognize under the microscope constituents of the studied 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 processes leading to the present rock state (reactions between the minerals, alterations, deformations),

- to describe in systematic way: the texture, name the rock and recognize the minerals composing it.

The acquired skills are monitored during exercises by constant interaction between teacher and students. Final assesment of skills acquired during classes is done by examining 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 Mineralogy and the assessement of crystal optics knowledge.