Geomorphology is concerned with the surface processes that create the landscapes of the world—namely, weathering and erosion.Weathering is the alteration and breakdown of rocks at the Earth’s surface caused by local atmospheric conditions, while erosion is the process by which the weathering products are removed by water, ice, and wind.The combination of weathering and erosion leads to the wearing down or denudation of mountains and continents, with the erosion products being deposited in rivers, internal drainage basins, and the oceans. The unconsolidated accumulated sediments are transformed by the process of diagenesis and lithification into sedimentary rocks, thereby completing a full cycle of the transfer of matter from an old continent to a young ocean and ultimately to the formation of new sedimentary rocks.Knowledge of the processes of interaction of the atmosphere and the hydrosphere with the surface rocks and soils of the Earth’s crust is important for an understanding not only of the development of landscapes but also (and perhaps more importantly) of the ways in which sediments are created.As a discipline, mineralogy has had close historical ties with geology.Minerals as basic constituents of rocks and ore deposits are obviously an integral aspect of geology.The geologic time scale, back to the oldest rocks, some 4,280,000,000 years ago, can be quantified by isotopic dating techniques.This is the science of geochronology, which in recent years has revolutionized scientific perception of Earth history and which relies heavily on the measured parent-to-daughter ratio of radiogenic isotopes ().
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).
Many rocks have a more complex mineralogy, and in some the mineral particles are so minute that they can be identified only through specialized techniques.
It is possible to identify an individual mineral in a specimen by examining and testing its physical properties.
Unmanned space probes have yielded significant data on the surface features of many of the planets and their satellites.
Since the 1970s even such distant planetary systems as those of Jupiter, Saturn, and Uranus have been explored by probes.
Thus a few minerals such as the feldspars, quartz, and mica are the essential ingredients in granite and its near relatives.