The purpose of petrology is to understand the conditions of the formation of rocks. The first stage of this approach is to describe and classify the rocks; that is the subject of petrography. Many characters can be used: density, hardness, colour, structure (on the scale of the outcrop), texture (on the scale of the sample or of the microscope), mineralogical composition, chemical composition, speed of propagation of the waves, etc. Among all the characters, the mineralogical composition is certainly the most important: it allows us to, more or less, accurately foresee the other characters and it can be used to determine the very conditions of the formation of rocks. Indeed, the nature and chemical composition of the minerals in a rock obey stricter laws, since the formation temperature was higher

The crust of the Earth and underlying relatively rigid mantle make up the lithosphere. The crust is composed of a great variety of minerals and rocks. More than 80% of all raw materials that are used in various sectors of economy, society and the environment are of mineral origin, and demand for them is greater every day. In most countries, the values of raw materials used for the metal industry and building materials exceed the value of the funds allocated for oil and gas, although, we hear more about oil and gas <...>

В монографии приведены результаты современного исследования геологических комплексов, слагающих уникальный ультрамафитовый массив Рай-Из на Полярном Урале, вмещающий промышленные залежи хромовых руд. Прослежена эволюция вещества ультрамафитов в ходе длительной метаморфической истории массива. На основе анализа оливин-хромшпинелевого парагенезиса, выполненного как для ранних ассоциаций ультраосновных пород, так и для продуктов их метаморфизма и локализованных в них хромититов, сделан вывод об P-T-fO2 условиях формирования породных комплексов и оруденения. Приведены результаты минералогического и геохимического исследования хромититов, ультрамафитов, а также жильных образований, участвующих в строении массива Рай-Из.
Работа предназначена для геологов, петрологов и специалистов в рудной геологии, занимающихся ультрамафитами, хромовыми рудами, а также офиолитовыми комплексами в целом.

The science of igneous petrology is founded on astute observation of rocks, guided by the rigorous principles of physical chemistry. It is, perhaps, the wedding of fallible observation with rigorous theory that makes this such a delicious science. In view of this, it is appropriate to study rocks and phase diagrams hand in hand. Good books on petrography abound, but there are few introductory books on phase diagrams, and none that illustrate in detail the quantitative analysis of fractional and equilibrium crystallization and melting, the four limiting processes capable of rigorous discussion. This book is an attempt to remedy the deficiency <...>

Metamorphism refers lo Ihe inineni logical and structural alteration of rock к in Karth's crust, and excludes alteration at or just beneath ihe surface, such as weathering and early diagencsis. However, diagenetic changes grade into mctamorphic changes in burial meuimorphism. In face* metamor-phism may occur in several geological environments, because assemblages react to changes in temperature (T), pressure (iJ) and activities of mobile chemical components, regardless ol the geological processes responsible for the changes. For example, identical or very similar assemblages can be formed by (1) deuleric alteration in an igneous intrusion 12) wall-rock alteration around a hydro! hernia) orebody. (3) low-tempe rat lire alteration around an igneous intrusion, (4) burial metamorphism of sedimentary/volcanic successions and (5) alteration, both local and regional, in geothermal areas (Vernon. 1976f.

This volume is devoted to the memory of the Russian petrologist D.S. Korzhinskiy. The world community of geoscientists has highly valued his contributions to petrology, particularly the discovery and thermodynamic description of open systems with perfectly mobile components. Korzhinskiy's work reached this community's attention because his book Physicochemical Basis of the Analysis of the Paragenesis of Minerals (1959, Consultants Bureau, New York) was translated into English. However, in the Soviet Union D.S. Korzhinskiy is also highly regarded for his contributions to geology and study of ore deposits as well as to theoretical petrology. Stratigraphy and geology of the Precambrian Aldan shield in Eastern Siberia; origin of lapis lazuli and phlogopite deposits and iron formations; boron mineralization; genesis of skarns and general theory of metasomatic zoning; origin of granites, charnockites and anorthosites; theory of the acid-basic interaction of components in the dry silicate melts: all of these were subjects of his more than 200 papers and books. The papers in the present volume span Korzhinskiy's broad interests. These papers were selected with the aim of illustrating the progress made in physicochemical petrology since Korzhinskiy.

Igneous petrology is the study of melts (magma) and the rocks that crystallize from such melts, encompassing an understanding of the processes involved in melting and subsequent rise, evolution, crystallization, and eruption or emplacement of the eventual rocks. Origin by crystallization from a melt seems a simple enough criterion for considering a rock to be igneous.

Petrology, from the Greek words petra , meaning rock, and logos, meaning knowledge, is the study of rocks and the conditions in which they form. It includes igneous, metamorphic, and sedimentary petrology.

Processes involved in the development of igneous and metamorphic rocks involve some combination of crystal growth, solution, movement and deformation, which is expressed as changes in texture (microstructure). Recent advances in the quantification of aspects of crystalline rock textures, such as crystal size, shape, orientation and position, have opened new avenues of research that extend and complement the more dominant chemical and isotopic studies.

Igneous and metamorphic petrology in the last decades of the twentieth century exploded into a broad, multifaceted, increasingly quantitative science. Advances in physical and field petrology and geochemistry have forever changed our thinking about the origin and evolution of magmas, their dynamic behavior, and the way in which they are intruded and explosively extruded. Developments in geochronology, quantitative evaluation of the role of heat and fluid transfer in crustal rocks, and new field discoveries have impacted our understanding of the evolution of metamorphic systems and their dynamic interaction with tectonic processes. Geophysics and mineral physics have provided new insights into the nature of the convecting mantle and its role as a giant heat engine driving magmatic and metamorphic processes. New tools of all kinds allow new ways of gathering petrologic data, while phenomenal developments in computers and computer software permit data to be stored, processed, and modeled in ways unimaginable as recently as a couple of decades ago.