| 词条 | Brachina meteorite |
| 释义 |
|Name = Brachina meteorite |Alternative names = |Image = |Image_caption = |Type = Primitive achondrite |Class = Asteroidal achondrite |Group = Brachinite |Structural_classification = |Composition = olivine, plagioclase, clinopyroxene, iron-sulfide, chromite, chlorapatite, pentlandite, meteoric iron, melt inclusions |Shock = |Weathering = |Country = Australia |Region = South Australia |Lat_Long = {{coord|31.300000|S|138.383333|E|display=inline,title}} |Observed_fall = No |Fall_date = |Found_date = 26 May 1974 |TKW = {{convert|202.85|g}} (2 fragments) |Image2 = |Image2_caption = }} The Brachina meteorite is the type specimen of the brachinites class of the asteroidal achondrites. Naming and discoveryThe meteorite is named after Brachina in South Australia. Two fragments (total 200 g) were found by B.M. Eves at {{Coord|31.300000|S|138.383333|E|display=inline}} on 26 May 1974.[1] DescriptionThe mineral composition of the Brachina meteorite is olivine (80%), plagioclase (10%), Clinopyroxene (5.5%), iron-sulfide (3%), chromite (0.5%), chlorapatite (0.5%) and pentlandite (0.3%) and traces of meteoric iron. Melt inclusions consist of glass with orthopyroxene and anorthoclase. The chemical and mineralogical composition is similar to the Chassigny meteorite, but the trace elements are fundamentally different.[2] Parent bodyMelt inclusions indicate that there were melting processes active on the brachinite parent body.[2] ClassificationThe meteorite was classified as a chassignite in 1978,[3] but in 1983 trace element analysis showed that the Brachina meteorite was fundamentally different from Chassigny. It was therefore proposed that the meteorite should be the type specimen of a new meteorite class, the brachinites.[2] This classification has remained valid since then.[1][4] See also
References1. ^1 {{cite web|title=Brachina|url=http://www.lpi.usra.edu/meteor/metbull.php?sea=Brachinite&sfor=types&ants=&falls=&valids=&stype=exact&lrec=2000&map=ge&browse=&country=All&srt=name&categ=All&mblist=All&rect=&phot=&snew=0&pnt=Normal%20table&code=5127|publisher=Meteoritical Society|accessdate=15 December 2012}} {{Meteorites}}{{Meteorites by name}}2. ^1 2 {{cite journal|last=Nehru|first=C. E.|author2=Prinz, M. |author3=Delaney, J. S. |author4=Dreibus, G. |author5=Palme, H. |author6=Spettel, B. |author7= Wänke, H. |title=Brachina: A new type of meteorite, not a chassignite|journal=Journal of Geophysical Research|date=1 January 1983|volume=88|issue=S01|pages=B237|doi=10.1029/JB088iS01p0B237 |bibcode=1983JGR....88..237N}} 3. ^{{cite journal|last=Graham|first=A. L.|journal=The Meteoritical Bulletin|year=1978|volume=55|pages=331|bibcode=1978Metic..13..327G }} 4. ^{{cite book|last=Grady|first=Monica M.|title=Catalogue of meteorites|year=2000|publisher=Cambridge University Press|location=Cambridge|isbn=9780521663038|edition=5th ed. rev. and enl.}} 2 : Achondrite meteorites|Meteorites found in Australia |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。