General geology

The general geology includes the phenomenological and theoretical aspects of geology . It is distinguished in particular from applied and historical geology , and in part also from the geological survey ( geological maps and their production).

The main research topics in general geology

• the near-surface and subterranean forces that act on the earth's body
• the resulting formation and classification of the rocks ,
  • in particular igneous rocks ( deep and effusion rocks ), the sedimentary rocks formed from them , and the transformation to metamorphic rocks
  • the composition of the rocks (see also mineralogy and petrography )
  • the specific rock characteristics in terms of ( structure and structure )

Endogenous and exogenous forces

The forces or processes are differentiated according to their cause into exogenous (on the earth's surface ) and endogenous forces (inside the earth).

While the small-scale analyzes are more the subject of geological surveys ( excursions , geological maps) or applied geology (natural hazards, exploration of raw materials, principles of construction ), large-scale investigations are primarily the task of general geology. Typical of this is research into the rock cycle and the processes that drive it - see also plate tectonics . There is a close cooperation to geophysics and geodesy .

The general geologist works on a somewhat smaller scale (in more detail) . B. in researching erosion and sedimentation , which he traditionally classifies as follows:

• physical causes (water, ice, wind, landslides) and the associated processes of deposition ( debris heaps, gravel, sand, clay, etc. and their subsequent solidification ( diagenesis )), furthermore
• chemical causes such as weathering and precipitation (e.g. salts, mountain milk, gypsum, limestone)
• biogenic sediments (especially many types of limestone ). There is a close connection here with soil science .

Other important research topics include a. large-scale metamorphosis and tectonics (see also plate tectonics and mountain formation ) and volcanism or the formation of plutonites (granite etc.). Quaternary geology (geological-sedimentological consequences of the ice ages ) and fracture tectonics , both of which lead to the formation of many flat, densely populated habitats on our planet ( flatlands , tectonic and sedimentary basins ) , are also essential for understanding land forms and their formation .

While until about 1970 the geologists examined the displacements and forces occurring in all these processes in a descriptive and qualitative manner , for some decades now, numerical geology has also been introducing physically and mathematically more strictly modeled investigations into the earth sciences . Difficult questions include: a. the modeling of physical forces , which in view of the diversity of rocks , their mechanical-chemical properties and their storage conditions often turns into Sisyphean work.

As a long-term goal of general geology, besides the comprehensive description of the Earth's body - in cooperation with geophysics and geology - apply not only to observe the movements and forces of internally "living earth" and to interpret , but also to describe physically and predictions come to can.

See also

• Earth history , earth crust , upper earth mantle
• Structural geology , landform studies , glaciology
• Mountain formation , folding , thrusting ,
• geological fault , shear , foliation .

literature

• F. Press and R. Siever: General geology . Spektrum Akademischer Verlag GmbH, Heidelberg-Berlin-Oxford, 1995