Geochemistry

Geochemistry is the science that uses the tools and 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. It is an integrated field of chemistry and geology. thumb|center|1100px|alt=Time-lapse sequence showing a water droplet forming at the tip of a stalactite.|T

pathway by which a chemical element or molecule moves through both biotic and abiotic compartments of Earth

climate change-induced decline of pH levels in the ocean

right|thumb|Cross-section illustrating the soil layer, showing the topsoil (A); [[regolith (B); and saprolite, a less-weathered regolith (C).]] The pedosphere () is the outermost layer of the Earth's crust that is composed of soil and subject to soil formation and erosion processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The pedosphere is the "stratum corneum" of the Earth's surface and only develops when there is a dynamic interaction between the atmosphere (air in and above the soil), biosphere (living organisms and associated organic matters),

actions to limit climate change in order to reduce the risks of global warming

thumb|upright=0.5|Fulgurite

chemical element whose concentration (or other measure of amount) is very low

volcano in Ethiopia

Sapropel (a contraction of Ancient Greek words sapros and pelos, meaning putrefaction and mud (or clay), respectively) is a term used in marine geology to describe dark-coloured sediments that are rich in organic matter. Organic carbon concentrations in sapropels commonly exceed 2 wt.% in weight.

shower of mostly organic detritus falling from the upper layers of the water column

any of several measures of the occurrence of different chemical elements

nuclides predating the Earth's formation (found on Earth)

geochemical classification grouping the chemical elements according to their preferred host phases

thumb|300px|Thorium concentrations on the Moon, as mapped by [[Lunar Prospector. Thorium correlates with the location of KREEP.]] KREEP, an acronym built from the letters K (the atomic symbol for potassium), REE (rare-earth elements) and P (for phosphorus), is a geochemical component of some lunar impact breccia and basaltic rocks. Its most significant feature is somewhat enhanced concentration of a majority of so-called "incompatible" elements (those that are concentrated in the liquid phase during magma crystallization) and the heat-producing elements, namely radioactive uranium, thorium, an

A micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteoroids as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).

250px|thumb|right|Tephra horizons in south-central Iceland. The thick and light coloured layer at the height of the [[volcanologist's hands is rhyolitic tephra from Hekla.]]

processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption

thumb|SEM image of a geopolymer granule prepared from metakaolin by alkaline activation to be further used as a sorbent. A geopolymer is an inorganic, often ceramic-like material, that forms a stable, covalently bonded, non-crystalline to semi-crystalline network through the reaction of aluminosilicate materials with an alkaline or acidic solution. Many geopolymers may also be classified as alkali-activated cements or acid-activated binders. They are mainly produced by a chemical reaction between a chemically reactive aluminosilicate powder e.g. metakaolin or other clay-derived powders, natura

Contamination is the presence of a constituent, impurity, or some other undesirable element that renders something unsuitable, unfit or harmful for the physical body, natural environment, workplace, etc.

subfield of geology focused on the study of natural variations in the relative abundances of isotopes of various elements

relative abundance of elements in Earth's crust

chemical composition of marine environments

isotopes that are produced by interaction of cosmic rays with the nucleus of the atom

one that is unsuitable in size and/or charge to the cation sites of the minerals of which it is included, and is defined by the partition coefficient between rock-forming minerals and melt being much smaller than 1

ratio

term in chemistry: long-term transformation of silicate rocks to carbonate rocks by weathering and sedimentation, and the transformation of carbonate rocks back into silicate rocks by metamorphism and volcanism

thumb|The graphic presents the present-day annual mean surface omega calcite: the normalised saturation state of calcite. Areas with a value less an 1 indicate a likeliness for dissolution (undersaturated) while a value over 1 indicates areas less likely for dissolution (oversaturation). The lysocline is the depth in the ocean dependent upon the carbonate compensation depth (CCD), usually around 5 km, below which the rate of dissolution of calcite increases dramatically because of a pressure effect. While the lysocline is the upper bound of this transition zone of calcite saturation, the CCD i

In geochemistry, paleoclimatology, archaeology, and paleoceanography '''δC''' (pronounced "delta carbon thirteen") is a normalized ratio of the two stable isotopes of carbon—C and C—reported in parts per thousand (per mille, ‰).

type of igneous rock

In geochemistry, paleoclimatology and paleoceanography '''δ18O or delta-O-18''' is a measure of the deviation in ratio of stable isotopes oxygen-18 (18O) and oxygen-16 (16O). It is commonly used as a measure of the temperature of precipitation, as a measure of groundwater/mineral interactions, and as an indicator of processes that show isotopic fractionation, like methanogenesis. In paleosciences, 18O:16O data from corals, foraminifera and ice cores are used as a proxy for temperature.

juvenile water

soil -exchange of gases between plant roots and the atmosphere

study of the impacts and processes that organisms have had on the Earth

pathway that chemical elements take in the surface and crust of the Earth

scientific method used to age or date obsidian objects

Graph of concentrations of different species of a polyprotic acid, as a function of pH, when the solution is at equilibrium

water that collects in a mine and which has to be brought to the surface by water management methods

liquid and/or gas trapped within a crystal

American science award in geochemistry

branch of the Geology of Mars

an estimate of the mineralogy of the rock

large area of molten rock on the surface of a planet

specialization of mass spectrometry

applied subdiscipline of chemistry

radionuclide formed by nucleosynthesis before formation of the Solar System

In geochemistry, hydrology, palaeoecology, palaeoclimatology, and palaeoceanography, '''δ15N (pronounced "delta fifteen n") or delta-N-15''' is a measure of the ratio of the two stable isotopes of nitrogen, 15N:14N.

Sediment in water

physico-chemical process that transports dissolved inorganic carbon from the ocean's surface to its interior

threat to the reef which reduces the viability and strength of reef-building corals

term

how the various types of mineral deposits form within the Earth's crust.