geology, the fields of study concerned with the solid Earth.

Included are sciences such

as mineralogy, geodesy, and stratigraphy.

An introduction to the geochemical and geophysical sciences logically begins

with mineralogy, because Earth’s rocks are composed of minerals—inorganic elements
or compounds that have a fixed chemical composition and that are made up of regularly
aligned rows of atoms. Today one of the principal concerns of mineralogy is
the chemical analysis of the some 3,000 known minerals that are the
chief constituents of the three different rock types: sedimentary (formed by diagenesis
of sediments deposited by surface processes); igneous (crystallized from magmas either
at depth or at the surface as lavas); and metamorphic (formed by a recrystallization
process at temperatures and pressures in the Earth’s crust high enough to destabilize
the parent sedimentary or igneous material). Geochemistry is the study of the
composition of these different types of rocks.

During mountain building, rocks became highly deformed, and the primary

objective of structural geology is to elucidate the mechanism of formationof
the many types of structures (e.g., folds and faults) that arise from
such deformation. The allied field of geophysics has several subdisciplines,
which make use of different instrumental techniques. Seismology, for
example, involves the exploration of the Earth’s deep structure through the
detailed analysis of recordings of elastic waves generated by earthquakes and
man-made explosions. Earthquake seismology has largely been responsible for
defining the location of major plate boundaries and of the dip of subduction
zones down to depths of about 700 kilometres at those boundaries. In other
subdisciplines of geophysics, gravimetric techniques are used to determine the
shape and size of underground structures; electrical methods help to locate a
variety of mineral deposits that tend to be good conductors of electricity; and
paleomagnetism has played the principal role in tracking the drift of
continents.

(Source: Brittanica.com)