Geochemistry

Introduction

Geochemistry is the branch of earth science that applies the principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the entire Solar System, and has made important contributions to the understanding of a number of processes including mantle convection, the formation of planets and the origins of granite and basalt.

History

The field of geochemistry was first established by the Swiss-German chemist, Victor Moritz Goldschmidt, in the early 20th century. Goldschmidt's work is renowned for defining the abundance of elements within the Earth's crust. His work laid the foundation for geochemistry, defining the discipline as an important subset of earth science.

Branches of Geochemistry

Geochemistry can be divided into various sub-disciplines, including:

Isotope Geochemistry

Isotope geochemistry involves the determination of the relative and absolute concentrations of the elements and their isotopes in the earth and on earth's surface. This branch of geochemistry uses the principles of stable and radioactive isotopes to study the age of the Earth, meteorites, and moon rocks. It also studies the isotopic compositions of past and present oceans, weathering, and climate change.

Biogeochemistry

Biogeochemistry is the field of study focusing on the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment and the cycles of matter and energy that transport the Earth's chemical components in time and space.

Organic Geochemistry

Organic geochemistry involves the study of the impacts and processes that organisms have had on Earth. Organic geochemistry is used to study the processes that have led to the formation of fossil fuels, such as oil and gas. It also includes the study of extraterrestrial life.

Environmental Geochemistry

Environmental geochemistry focuses on the study of the chemical processes and reactions that occur in the environment and the effects of human activity on these processes.

Cosmochemistry

Cosmochemistry is the study of the chemical composition of matter in the universe and the processes that led to those compositions. This is done primarily through the study of the chemical compositions of meteorites and other extraterrestrial materials.

Geochemical Techniques

Geochemists employ a variety of techniques to analyse the Earth's surface, including:

Geochemical Prospecting

In geochemical prospecting, geochemists analyze the physical and chemical properties of rock samples to look for anomalies that may indicate the presence of valuable minerals.

Geochemical Modeling

Geochemical modeling allows geochemists to use data about the concentrations of elemental species in rocks and fluids to model their interactions with the environment. This can include predicting the impacts of climate change on natural resources or the behavior of pollutants in the environment.

Geochemical Cycles

Geochemical cycles refer to the pathway by which chemical elements move through the Earth's systems. The most important of these are the carbon cycle and the nitrogen cycle.

The Carbon Cycle

The carbon cycle is the process by which carbon compounds are interconverted in the environment. This involves the absorption of carbon dioxide by plants as photosynthesis, the ingestion and metabolism of these plants by animals, and the release of carbon dioxide into the atmosphere through respiration, decay and combustion.

The Nitrogen Cycle

The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms. This transformation can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification.

Conclusion

Geochemistry is an essential field of science that helps in understanding the Earth's system and how it is changing over time. By studying the chemical properties and processes of the Earth's system, geochemists can contribute to the knowledge about the Earth's past, present and future.