Astronomy:Wehrlite
Wehrlite is an ultramafic and ultrabasic rock that is a mixture of olivine and clinopyroxene. It is a subdivision of the peridotites.
The nomenclature allows up to a few percent of orthopyroxene. Accessory minerals include ilmenite, chromite, magnetite and an aluminium-bearing mineral (plagioclase, spinel or garnet).[1]
Wehrlites occur as mantle xenoliths and in ophiolites. Another occurrence is as cumulate in gabbro and norite layered intrusions.[1] Some meteorites can also be classified as wehrlites (e.g. NWA 4797).[2]
Wehrlite is named after Alois Wehrle.[3] He was born 1791 in Kroměříž, Czech Republic (then Kremsier in Mähren) and was a professor at the "Ungarische Bergakademie" (Hungarian Mining School) in Banská Štiavnica, Slovakia (then Schemnitz, Kingdom of Hungary).[4]
Brachinites
Brachinites are a class of wherlitic primitive anachondrites that consist almost entirely of olivine, which ranges from 74 to 98% by volume. These often have accessory minerals such as plagioclase (6.7 to 12.9%), iron Sulfides (1.8 to 4.0%), clinopyroxene (1.5 to 8.2%) and orthopyroxene (0 to 2.4%) with traces of phosphates and meteoritic iron. The only deviation from regular chondrites is their high olivine to orthopyroxene ratio.[5]
References
- ↑ 1.0 1.1 "Glossary: Wehrlite". Imperial College. https://www2.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000094. Retrieved 12 January 2013.
- ↑ "NWA 4797". curator.jsc.nasa.gov. http://curator.jsc.nasa.gov/antmet/mmc/nwa4797.pdf. Retrieved 12 January 2013.
- ↑ "Department of Mineralogy and Petrography". uni-miskolc.hu. http://fold32.ftt.uni-miskolc.hu/~intezet/index.php/en/department-of-mineralogy-and-petrology. Retrieved 12 January 2013.
- ↑ "ADB:Wehrle, Alois". WikiSource. http://de.wikisource.org/w/index.php?title=ADB:Wehrle,_Alois&oldid=1686501. Retrieved 12 January 2013.
- ↑ Nehru, C. E.; M. Prinz; M. K. Weisberg; M. Ebihara; R. N. Clayton; T. K. Mayeda (1992). "Brachinites: A New Primitive Achondrite Group". Meteoritics 27 (3): 267.
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