Geology and Minerals

Diffusion chronometry

Diffusion chronometry is a geological technique that examines the chemical gradients within mineral crystals to estimate the duration of events in a magmatic system (e.g. magma mixing, magma decompression, magma degassing, etc.) and their associated eruptions. In simple terms, the mineral phenocryst acts as a "crystal clock" to determine how long a magmatic process took. Diffusion chronometry takes advantage of the common chemical disequilibrium found in volcanic phenocrysts and examines their kinetic window to obtain timescale information. Diffusion chronometry should not be confused with geospeedometry. Both utilize the theory of chemical diffusion, but the latter is more commonly used for analyzing rates of metamorphic events whereas the former is used to analyze features of eruptive events. Eruptive events can occur on a timescale of days or months which, geologically speaking, is difficult to analyze using traditional radiometric dating techniques. The use of diffusion chronometry on past eruptions can help in forecasting eruptions by gaining a better understanding of the timescales of magmatic processes and can aid in determining timescales for volcano alert levels during an eruptive event.

Also on this shelf

See also

• ▸Island arc
• ▸Donald Howard Menzel
• ▸Geology of Bangladesh

Uncatalogued shelf

Text from Wikipedia; plate via Wikimedia Commons. Text CC BY-SA 4.0; plate freely licensed (see Commons). Source record. Images and catalogue data are reproduced from open-access collections.