6 天之前 · Northwest Africa 7042 (NWA 7042) Morocco. Found: Oct 2011. Classification: Martian meteorite (Shergottite) History: A large stone was found in October 2011 in southern Morocco and purchased from nomads by two Moroccan dealers. Physical characteristics: A single 3033 g stone partly coated by thin, brownish remnant fusion crust. Weathered ...

2020年8月15日 · Here, we report the detailed petrology, mineralogy, alteration, and shock features in intermediate permafic shergottite Northwest Africa (NWA) 7042. Geochemically, it is intermediate in ITE, reflecting a transitional stage between ITE-depleted primary melts, and more evolved ITE-enriched magmas (Day et al., 2018).

As the timing of the alteration in NWA 7042 is of particular interest, this study 123 includes a detailed discussion of the relationships between shock features and the altered 124 olivine grains and examines the possibility of both terrestrial and martian formation

摘要 西北非 (NWA) 7042 是一种中性、永固性辉石，由两代橄榄石（早期分带橄榄石 Fo41-76 和后期铁橄榄石型橄榄石 Fo46-56）、复杂分带辉石（En35-64Fs22-46Wo5-34）组成、冲击熔解或蒙脱石化长石 (An5-30Ab16-61Or1-47)，以及附属的磷灰石、磷灰石、钛铁矿、钛磁铁矿 …

2020年6月4日 · Launch-generated shock veins in NWA 7042 crosscut and displace several of the altered olivine grains indicating that the alteration occurred before ejection of the meteorite from Mars. However, NWA 7042 has also been subjected to extensive terrestrial weathering, with terrestrial calcite/barite veins occurring throughout the sample.

NWA 7042 pyroxenes all exhibit inclined extinction, and occur as elongate euhedral crystals reaching several mm in longest dimension. Many display a sharp optical contact between cores and rims. Chemically, the rims of NWA 7042 clinopyroxene grains are Ca-rich, compared the complexly-zoned cores (Fig. 2) Maskelynite:

Northwest Africa (NWA) 7042 is an intermediate, permafic shergottite consisting of two generations of zoned olivine (early olivine Fo41-76, and late-stage olivine Fo46-56), complexly …

2020年6月8日 · Northwest Africa (NWA) 7042 is an intermediate, permafic shergottite consisting of two generations of olivine (early zoned olivine Fo41-76, and late-stage fayalitic olivine Fo46-56), complexly zoned pyroxene (En35-64Fs22-46Wo5-34), shock-melted or maskelynitized feldspar (An5-30Ab16-61Or1-47), and accessory merrillite, apatite, ilmenite ...

NWA 7042 consists of complexly-zoned pyroxene and zoned olivine with ~15 vol.% interstitial maske-lynite (An48.6-54.5Or1.7-1.8, in groups of lath-like grains in parallelt intergrowth with ferroan pigeonite), plus ac-cessory Ti-poor chromite, ilmenite (some intergrown with ulvöspinel), pyrrhotite and merrillite (see Figure 3).

2020年6月1日 · Northwest Africa (NWA) 7042 is an intermediate, permafic shergottite consisting of two generations of olivine (early zoned olivine Fo41-76, and late-stage fayalitic olivine Fo46-56),...