Data/hora: 13/06/2024 07:06:07

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	Petrology, geochemistry, and cosmic-ray exposure age of lherzolitic shergottite Northwest Africa 1950	
Autores: 	Gillet, P; Barrat, J; Beck, P; Marty, B; Greenwood, R; Franchi, I; Bohn, Marcel; Cotten, J.	
Data: 	2005-08	
Ano: 	2005	
Palavras-chave: 	Meteorites; Atlas Mountains; Shergottite; Lherzolitic.	
Resumo: 	Northwest Africa (NWA) 1950 is a new member of the lherzolitic shergottite clan of the Martian meteorites recently found in the Atlas Mountains. The petrological, mineralogical, and geochemical data are very close to those of the other known lherzolitic shergottites. The meteorite has a cumulate gabbroic texture and its mineralogy consists of olivine (FO66 to FO75), low and high-Ca pyroxenes (En(78)Fs(19)Wo(2)-En(60)FS(26)W(14); En(53)Fs(16)Wo(31)-En(45)Fs(14)Wo(41)), and plagioclase (An(57)Ab(41)Or(1) to An(40)Ab(57)Or(3); entirely converted into maskelynite during intense shock metamorphism). Accessory minerals include phosphates (merrillite), chromite and spinels, sulfides, and a glass rich in potassium. The oxygen isotopic values lie on the fractional line defined by the other SNC meteorites (Delta(17)O = 0.312 parts per thousand). The composition of NWA 1950 is very similar to the other lherzolitic shergottites and Suggests an origin from the same magmatic system, or at least crystallization from a close parental melt. Cosmogenic ages indicate an ejection age similar to those of the other lherzolitic shergottites. The intensity of the shock is similar to that observed in other shergottites, as shown by the occurrence of small melt pockets containing glass interwoven with stishovite.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/2005/publication-900.pdf	
Editor: 	The Meteoritical Society	
Relação: 	http://archimer.ifremer.fr/doc/00000/900/	
Formato: 	application/pdf	
Fonte: 	Meteoritics and Planetary Science (1086-9379) (The Meteoritical Society), 2005-08 , Vol. 40 , N. 8 , P. 1175-1184	
Fonte: 	The Meteoritical Society, 2005. Printed in USA.