from Wikipedia, the free encyclopedia

The petrography (rocks customer of Greek πέτρος Pétros "stone" and γράφειν Graphein "write", "scratch") is the descriptive science of the rocks , the "media types" of solid crust . It deals with the chemical and physical nature of rocks, their properties and their composition from individual minerals as well as their grain size and, in some cases, the crystal structure and is, in the narrower sense, a sub-discipline of petrology . Two important areas are sediment petrography and soil physics .

The term lithology is used for the field of petrography, which deals with the rock properties of sedimentary rocks . In addition, it is also often used for sediment structure as well as stratification / banking and other characteristics of the respective rock facies .

Important test methods are the chemical macro- and micro-analysis and the mineralogical examination of the rocks as well as the determination of the physical parameters of the rock (strength and elasticity, hardness , Berg humidity and dry density , layering, etc.). Also of great use are the separation methods used to isolate one or more mineral species from a composite rock. This separation is essentially carried out mechanically or chemically.

In the investigation and interpretation of the storage conditions, the metamorphosis and the respective causes of rearrangements, it overlaps with general and regional geology.

See also


Individual evidence

  1. Murawski, H .; Meyer, W. (2004): Geological dictionary. Spektrum Akademischer Verlag, 11th edition. 262 pp., ISBN 3-8274-1445-8 .