petrographicandmineralogicalstudiesofthelunarmeteoritedhofar1180

	petrographicandmineralogicalstudiesofthelunarmeteoritedhofar1180
	Zhang AC(张爱铖); Xu WB(徐伟彪)
刊名	actapetrologicasinica
	2007
卷号	23 期号:5 页码:1160
ISSN号	1000-0569
英文摘要	Dhofar 1180 is a newly found lunar meteorite in Oman. Here we report the detailed petrography and mineralogy of this new lunar meteorite with the hope to better understand of the geological processes on the Moon and the chemical composition of the lunar crust. Dhofar 1180 is a basalt-bearing feldspathic lunar breccia, containing various types of lithic clasts (gabbro, anorthositic gabbro, gabbroic anorthosite, troctolite, and microporphyritic crystalline impact melt breccia). Ti-bearing clasts and anorthositic melt clasts were also observed. Major mineral fragments include olivine, pyroxenes, plagioclase, and some opaque oxides. Olivine grains in gabbroic anorthosite, troctolite, and microporphyritic crystalline impact melt breccia are relatively enriched in Mg (Fo(55-69)), whereas those in anorthositic gabbro are relatively enriched in Fe (Fo(31)) . Olivine grains in Ti-bearing clasts show a wide compositional range (Fo(7-54)). Olivine fragments in the matrix are generally Fe-rich (Fo(2-46)). Fe/Mn molar ratios in olivine range from 69 to 113 with an average of 93, consistent with the lunar olivine trend. Pyroxene grains in gabbroic anorthosite, troctolite, microporphyritic crystalline impact melt breccia, and Ti-bearing clasts are mainly low-Ca pigeonite (En(63) Fs(32) Wo(5), En(66) FS23 Wo(11,) En(55) FS38 Wo(7) and En(57) FS35 Wo(8), respectively), and those in anorthositic gabbro, gabbro, and the matrix display a wide range of composition (En(31-33) FS35-48 Wo(19-34), En(18-48)FS(23-51)Wo(24-38) + En(1-9)Fs(65-86)Wo(14-26), En(11-53)Fs(23-63)Wo(6-36), respectively), mainly occurring as pigeonite, augite, and trace amounts of pyroxferroite. Pyroxene grains in Ti-bearing clasts contain relatively high Al2O3 (2.79%) and TiO2 (1.57%). Fe/Mn molar ratios in pyroxene vary from 50 to 70 with an average of 63, in good agreement with the lunar pyroxene trend. Plagioclase grains in Dhofar 1180 are highly anorthitic (An(91-98)). Opaque oxide minerals include chromite-spinel-ulvospinel solid solution and minor ilmenite. Dhofar 1180 is a unique lunar meteorite that differs petrographically and geochemically from all other lunar meteorites and lunar samples. It comes from a region on the lunar surface that has not been sampled by any other known lunar rocks. Dhofar 1180 thus enhances our understanding of the mineral and chemical compositions of the lunar surface.
语种	英语
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/28900]
专题	中国科学院紫金山天文台
作者单位	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Zhang AC,Xu WB. petrographicandmineralogicalstudiesofthelunarmeteoritedhofar1180[J]. actapetrologicasinica,2007,23(5):1160.
APA	张爱铖,&徐伟彪.(2007).petrographicandmineralogicalstudiesofthelunarmeteoritedhofar1180.actapetrologicasinica,23(5),1160.
MLA	张爱铖,et al."petrographicandmineralogicalstudiesofthelunarmeteoritedhofar1180".actapetrologicasinica 23.5(2007):1160.