The Ksar Ghilane 002 shergottite-The 100th registered Martian meteorite fragment
Visualitza/Obre
maps12074.pdf (825,3Kb) (Accés restringit)
Sol·licita una còpia a l'autor
Què és aquest botó?
Aquest botó permet demanar una còpia d'un document restringit a l'autor. Es mostra quan:
- Disposem del correu electrònic de l'autor
- El document té una mida inferior a 20 Mb
- Es tracta d'un document d'accés restringit per decisió de l'autor o d'un document d'accés restringit per política de l'editorial
Cita com:
hdl:2117/19936
Tipus de documentArticle
Data publicació2013-03
Condicions d'accésAccés restringit per política de l'editorial
Llevat que s'hi indiqui el contrari, els
continguts d'aquesta obra estan subjectes a la llicència de Creative Commons
:
Reconeixement-NoComercial-SenseObraDerivada 3.0 Espanya
Abstract
We report on the discovery of a new shergottite from Tunisia, Ksar Ghilane (KG)
002. This single stone, weighing 538 g, is a coarse-grained basaltic shergottite, mainly
composed of maskelynitized plagioclase (approximately 52 vol%) and pyroxene
(approximately 37 vol%). It also contains Fe-rich olivine (approximately 4.5 vol%), large
Ca-phosphates, including both merrillites and Cl-apatites (approximately 3.4 vol%), minor
amounts of silica or SiO2-normative K-rich glass, pyrrhotite, Ti-magnetite, ilmenite, and
accessory baddeleyite. The largest crystals of pyroxene and plagioclase reach sizes of
approximately 4 to 5 mm. Pyroxenes (Fs26–96En5–50Wo2–41). They typically range from cores
of about Fs29En41Wo30 to rims of about Fs68En14Wo17. Maskelynite is Ab41–49An39–58Or1–7
in composition, but some can be as anorthitic as An93. Olivine (Fa91–96) occurs mainly
within symplectitic intergrowths, in paragenesis with ilmenite, or at neighboring areas of
symplectites. KG 002 is heavily shocked (S5) as indicated by mosaic extinction of pyroxenes,
maskelynitized plagioclase, the occurrence of localized shock melt glass pockets, and low
radiogenic He concentration. Oxygen isotopes confirm that it is a normal member of the
SNC suite. KG 002 is slightly depleted in LREE and shows a positive Eu anomaly,
providing evidence for complex magma genesis and mantle processes on Mars. Noble gases
with a composition thought to be characteristic for Martian interior is a dominant
component. Measurements of 10Be, 26Al, and 53Mn and comparison with Monte Carlo
calculations of production rates indicate that KG 002 has been exposed to cosmic rays most
likely as a single meteoroid body of 35–65 cm radius. KG 002 strongly resembles Los
Angeles and NWA 2800 basaltic shergottites in element composition, petrography, and
mineral chemistry, suggesting a possible launch-pairing. The similar CRE ages of KG 002
and Los Angeles may suggest an ejection event at approximately 3.0 Ma.
CitacióLlorca, J.; Roszjar, J.; Cartwright, J.A. The Ksar Ghilane 002 shergottite-The 100th registered Martian meteorite fragment. "Meteoritics and planetary science", Març 2013, vol. 48, núm. 3, p. 493-513.
ISSN1086-9379
Versió de l'editorhttp://onlinelibrary.wiley.com/doi/10.1111/maps.12074/abstract
Fitxers | Descripció | Mida | Format | Visualitza |
---|---|---|---|---|
maps12074.pdf | 825,3Kb | Accés restringit |