Northwest Africa 5790. Top Sequence of the Nakhlite Pile
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چکیده
Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. Introduction: Northwest Africa (NWA) 5790 is the eighth nakhlite, found in the Sahara (Mauritania?) by nomads and purchased in Erfoud (Morocco). As will be seen below it is not paired with any previous find. Dating is reported elsewhere [1] Petrography: The texture is one of a lava (Fig.1) with dominant millimetric euhedral augite (51%) irregularly zoned in their cores and sharply rimmed. Other phe-nocrysts are subsidiary euhedral olivine (9%) of slightly larger size, steadily zoned to their core and rare titanomagnetite (<1%). Abundant mesostasis (40%) contains dendritic crystals of oxides, calcic pyroxene, fayalitic olivine, two feldspars, silica, merrilite, Cl-apatite and glass. Minor Cl-amphibole is trapped in melt inclusions. The texture (Fig 1) strongly recalls NWA 817 or MIL 03346 [2-4].
منابع مشابه
Top Sequence of the Nakhlite Pile
NORTHWEST AFRICA 5790. TOP SEQUENCE OF THE NAKHLITE PILE. A. Jambon J-A. Barrat2,3, C. Bollinger2,3, V. Sautter4, O. Boudouma1 , R.C. Greenwood5, I.A. Franchi5 and D. Badia1, 1UPMC Univ Paris 06, ISTEP CNRS-UMR 7193, Paris France [email protected] , 2Université Européenne de Bretagne, 3Université de Brest CNRS-UMR 6538 IUEM, 29280 Plouzané France, MNHN Paris, Laboratoire de Minéralogie et C...
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تاریخ انتشار 2016