[Geography Notes] on Petrology Pdf for Exam

Geology is defined as the study of the Earth, studying the materials by which it is made. Geology also studies the structure of those materials and the processes which act upon them. This also includes the study of other organisms that thrive on our planet.

The Geologists for this matter study the materials, its process-related, products, the physical nature, and the history of the Earth. The Geomorphologists study the Earth’s landforms and its definite landscapes which is in relation to the geologic and the climatic processes and they also study human activities. 

Petrology is another branch of geology that studies the rocks and the conditions under which they structure out. Petrology has three other subdivisions, they are – igneous, metamorphic, and sedimentary petrology.

Petrology Meaning 

Petrology is defined as the study of rocks – namely igneous, sedimentary and metamorphic rocks. The process and forms and thus get transformed. While mineralogy is the study of chemistry, it studies the crystal structure and physical properties of the mineral constituents of rocks. Both these processes – petrological and mineralogical are very much sensitive to the environmental conditions. Hence, the compositions of rocks, and the minerals they consist of, are quite interesting to answer the most basic questions which also satisfy a wide range of geological disciplines.

We use petrology to study how the volcanoes were formed and their magmatic sources, via this study we also get to know the evolution of continental crust during the growth and destruction of the mountain belts, the genesis of the accessory minerals like the REE phosphates in all rock types, the origins of economic concentrations of minerals and the petroleum, the make-up of the atmosphere, ocean and life on Earth through the passage of time, and the geological processes which occur on other planets.  

Igneous Petrology

Igneous petrology studies the identification, classification, origin, evolution, and also processes of formation of the crystallization of these igneous rocks. Most of the rocks which are available for study thus come from the Earth’s crust, while a few like eclogitic are derived from the mantle. 

While studying igneous petrology, the researcher generally employs a phase of equilibrium approach that is very much comparable to the mineral assemblages which are found in the naturally occurring and synthetic rocks. 

From this, we can learn quite a good deal about the melting of an igneous rock. We also can study the reverse process of the crystallization of these minerals that are from a melt (or from the liquid phase). 

Mineralogy and Petrology 

Mineralogy and Petrology embrace and include manuscripts from the classical fields of crystallography, mineralogy, petrology, geochemistry, along with their applications in academic experimentation and also in research. Here the materials science and engineering, for technology, industry, environment, or society. The journal also strongly promotes the cross-fertilization which occurs among the Earth-scientific and they are applied materials-oriented for the disciplines. These are purely descriptive manuscripts based on regional topics which will not be considered.

Sedimentary Petrology 

In the field, where sedimentary petrology is studied, the main concern is with the description and with the classification of the sedimentary rocks, it studies the interpretation of the processes of the transportation and also the deposition of these sedimentary materials which forms the rocks. The environment which prevailed during the sediments was responsible for this. 

Metamorphic Petrology

Metamorphic petrology majorly covers the chemical and also the physical work which is done in the natural systems quite in response to the changing physical conditions. The petrogenetic processes like recrystallization, continuous and discontinuous reactions, mixed volatile reactions, and also deformation is being addressed here. The principles which are related to metamorphic petrology are applied to a number of orogenic events through geologic time, and modern advances in research in metamorphic petrology are then explored.

Igneous and Metamorphic Petrology 

Igneous Petrology

In this section we are aware of the principles of Igneous and Metamorphic Petrology which features over 250 contributions that are from more than 100 earth scientists based from 18 countries, In the Encyclopedia of Igneous and Metamorphic Petrology studies the nature and genesis of these igneous rocks which have crystallized into the form of molten magma. They are the metamorphic rocks which are residues of re-crystallization that are associated with the increases in temperature and pressure, this is mainly at considerable depths hidden in the Earth’s crust. 

The entries which range from the alkaline rocks to the rocks which are known as zeolite facies – provide other information on the concept of mineralogical, chemical and textural characters of these rock types.

Metamorphic petrology also covers the chemical and also the physical work which is done in natural systems, which is in response to changing the physical conditions. Petrogenetic is the processes like the recrystallization, continuous and the discontinuous reactions, which are mixed volatile reactions and the deformation is addressed thereby.