The term “geochemistry” was first used by the German-Swiss chemist Christian Friedrich Schönbein* in 1838. You might guess, merely from the etymology of the word, that the field of geochemistry is somehow a marriage of the fields of geology and chemistry. That would be a good guess. But just how are chemistry and geology combined within geochemistry; what is the relationship between them? Perhaps the best explanation would be to state that in geochemistry, we use the tools of chemistry to solve geological problems; that is, we use chemistry to understand the Earth and how it works.

Geochemistry is a branch of earth science. Since it is a field of study that uses the tools and principles of chemistry to explain the mechanisms in geologic environments, it often focuses on determining processes that control the abundance and composition of minerals and their distribution in the earth’s crust. Geochemistry also plays a vital role in environmental soil and water systems in identifying and modulating environmental problems, and in studying the composition, structure and processes of the earth.

The geochemical analysis of fades is a special part of geochemistry and geology. The development of this research was initiated by BISCHOF (1847-1851), who was the first to attempt to recognize sediments of different origin by geochemical means. In his now famous book he listed some chemical elements belonging to typical environments, such as boron in marine sediments and metallic sulphides in zones rich in sulphuretted hydrogens. Moreover he was the first author to suppose that all "soluble rocks" of the continents must be present in the oceans. This early concept of facies was supplemented by ROTH (1879-1890) who discovered new elements in the ocean waters and in the ashes of marine organisms. However, the data used by both of these workers were quantitatively unsatisfactory and can only be considered as the qualitative results of inadequate chemical analyses <...>

Many of the methods now used for gold extraction are based on techniques that have been known or established for centuries. Gravity concentration, amalgamation, cyanide leaching, chlorination, zinc precipitation, and carbon/charcoal adsorption are all processes that have been used for at least a hundred years, and combinations of these remain as the basis for most gold recovery flowsheets.

В дайной брошюре обобщен опыт работы центральной и экспедиционных лабораторий Северо-Западного геологического управления Министерства геологии и охраны недр СССР по организации и производству массовых анализов руд и пород, содержащих редкие элементы: ниобий, тантал, бериллий, цирконий, литий, рубидий, цезий и группу редких земель.

Minerals are intrinsically resistant to the processes that homogenize silicate liquids—their compositions thus yield an archive of volcanic and magmatic processes that are invisible at the whole rock scale. Minerals and their inclusions record diverse magma compositions, the depths and temperatures of magma storage, the nature of open system processes, and the rates at which magmas ascend.

Melt inclusions (MI) are small droplets of melt now containing some combination of crystals, glass and vapor that are trapped in crystals formed in magmas. Over the past few decades, the study of MI has matured to become an accepted technique to investigate melt evolution in volcanic systems (Clocchiatti 1975, Roedder 1979, Lowenstern 1995, 2003, Sobolev 1996, Frezzotti 2001, Hauri et al. 2001, Anderson 2003, Schiano 2003). MI in volcanic rocks are commonly large (>50 µm), glassy and contained in fresh and transparent minerals, and are generally easy to identify. MI in volcanic rocks generally provide consistent and reasonable results concerning the chemistry of melts at depth and provide the best tool available for assessing the volatiles in magmas (Anderson 1973, 1974, Lowenstern 1994, 1995, 2003). The best MI are often found in the most rapidly cooled parts of pyroclastic deposits and glassy rinds of lavas, which are not so easy to find (A.T. Anderson, Jr., personal communication, 2006).

The Middle Miocene Orduzu volcanic suite, which is a part of the widespread Neogene Yamadag˘ volcanism of Eastern Anatolia, consists of a rhyolitic lava flow, rhyolitic dykes, a trachyandesitic lava flow and basaltic trachyandesitic dykes. Existence of mafic enclaves and globules in some of the volcanic rocks, and microtextures in phenocrysts indicate that magma mingling and mixing between andesitic and basaltic melts played an important role in the evolution of the volcanic suite. Major and trace element characteristics of the volcanic rocks are similar to those formed in convergent margin settings.

Geochemistry is the study of the development, and distribution of chemical elements on Earth, which are found in rock-forming minerals and their byproducts, as well as in living beings, water, and the environment. The elemental geochemical variation of sediments is used to recognize the mechanisms controlling the estuarine environment and serves as a baseline for assessing the environmental effect in the future. Geochemistry is a unique field that deals with the study of mineral deposits.