Paragenesis
As paragenesis (after Greek para : beside, and genesis : origin) is called the characteristic association of various minerals at its education center, depending on the prevailing physical and chemical conditions. The term was introduced by August Breithaupt in 1849 . The formation is not limited to crystallization from a melt or a mineralizing solution, but processes such as metamorphosis , diagenesis of sediment and weathering of rock also lead to specific paragenesis. Since only very few minerals occur on their own, but most of them in a corresponding association, paragenesis is an important factor both in deposit science and in the identification of minerals and the rocks built from them.
For example, if quartz (SiO 2 ) is present in a rock, the occurrence of olivine ((Mg, Fe) 2 [SiO 4 ]) or the feldspar representatives leucite (K [AlSi 2 O 6 ]) and nepheline (Na [AlSiO 4 ]), since quartz stands for SiO 2 supersaturation. It therefore occurs mainly in paragenesis with the minerals andalusite , kyanite , muscovite and staurolite, which are similar in their formation conditions . The minerals olivine, nepheline and leucite, which also usually occur together, stand for SiO 2 undersaturation, which other mafish minerals such as amphiboles and pyroxenes also need.
Another example of typical paragenesis are the minerals galena ( galena , PbS), sphalerite (zinc blende, ZnS) and chalcopyrite (copper pyrites, CuFeS 2 ), which usually occur together (formation in hydrothermal ducts). Sphalerite and chalcopyrite are therefore also referred to as paragenesis minerals or accompanying minerals to galena.
If one does not consider the socialization of certain minerals, but only some of their chemical components, one speaks of element paragenesis or element socialization .
literature
- August Breithaupt: The paragenesis of minerals. Illuminated mineralogically, geognostically and chemically, with special consideration for mining . JG Engelhardt, Freiberg 1849.
Web links
- Mineral Atlas: Paragenesis and Accompanying Mineral (Wiki)
Individual evidence
- ↑ Author collective: Lexicon of Geosciences, Vol. III . 1st edition. Spektrum Akademischer Verlag, Heidelberg 2000, ISBN 3-8274-0422-3 , p. 398 .
- ↑ August Breithaupt : The Paragenesis of Minerals. Illuminated mineralogically, geognostically and chemically, with special consideration for mining . 1st edition. JG Engelhardt, Freyberg 1849, p. 1 ( available online in The Paragenesis of Minerals in the Google book search).