Petrology

Source: Wikipedia, the free encyclopedia.
A thin section of a volcanic sand grain seen under the microscope, with plane-polarized light in the upper picture, and cross-polarized light in the lower picture. Scale box is 0.25 mm.

Petrology (from

Ancient Greek πέτρος (pétros) 'rock', and -λογία (-logía) 'study of') is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology.[1] Igneous and metamorphic petrology are commonly taught together because both make heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock.[2]
Modern sedimentary petrology is making increasing use of chemistry.

Background

Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details.

In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through and drawn on a log called a mud log. As the cuttings are circulated out of the borehole, they are sampled, examined (typically under a 10× microscope) and tested chemically when needed.

Methodology

Ljudmila Dolar Mantuani (1906–1988), first female professor of petrography in Yugoslavia.

Petrology utilizes the fields of

thermodynamic
data and experiments in order to better understand the origins of rocks.

Branches

There are three branches of petrology, corresponding to the three types of rocks:

sedimentary
, and another dealing with experimental techniques:

See also

References

Citations

  1. .
  2. ^ Frost, B. R.; Frost, C. D. (2014). Essentials of Igneous and Metamorphic Petrology. Cambridge University Press.
  3. ^ .

Sources

External links