|
|||||
|
|
| 100块南极格罗夫山陨石的化学-岩石类型 | |
| 引用本文： | 胡森,刘焘,冯璐,徐琳,林杨挺.100块南极格罗夫山陨石的化学-岩石类型[J].极地研究,2008,20(2):208-218. |
| 作者姓名： | 胡森 刘焘 冯璐 徐琳 林杨挺 |
| 作者单位： | 1. 中国科学院地质与地球物理研究所地球深部研究重点实验室,北京,100029 2. 中国科学院广州地球化学研究所,广州,510640 3. 中国科学院国家天文台,北京,100012 |
| 基金项目： | 中国科学院知识创新方向性研究项目 , "百人计划"项目,以及国家科技基础条件平台建设项目 |
| 摘 要： | 本文报道100块南极格罗夫山陨石的岩矿特征,以及它们的化学群和岩石类型。分类结果共发现4块特殊类型陨石,包括1块CM2型碳质球粒陨石(GRV050179),1块钙长辉长无球粒陨石(GRV051523),1块橄辉无球粒陨石(GRV 052382)和1块中铁陨石(GRV 050212)。GRV050179大部分球粒直径小于300μm,基质/球粒体积百分比为6∶1,且具有强烈的水蚀变特征,形成大量层状硅酸盐和PCP(Poor Characterized Phases)集合体。GRV 052382的橄榄石具有还原边,内部重结晶。橄榄石和辉石之间的富碳填隙物含有金刚石。GRV 050212的金属含量为12.3 vol%,其中的低钙辉石FeO/MnO质量百分比为30.0,而GRV 051523中辉石的FeO/MnO质量百分比为28.7-30.9,两者均与HED(Howardites-Eucrites-Diogenites)族陨石一致。普通球粒陨石有93块,其中5块属于非平衡型普通球粒陨石。依据橄榄石Fa的相对标准偏差(PMD)可以进一步划分这些非平衡型普通球粒陨石的亚型1],其结果为:GRV 050165和GRV053167为3.5型,GRV050189、GRV050200和GRV050404为3.4型。88块平衡型普通球粒陨石包括低铁群(L)54块,高铁群(H)34块,与南极横贯山脉的陨石相比,L群所占比例明显偏高,且缺失LL群。另有3块小样品主要由金属和少量硅酸盐组成,其铁纹石的钴含量和橄榄石的Fa值分别落在H和L群范围。虽然这3块样品的金属含量类似铁陨石,但实际上很可能是普通球粒陨石中脱落的较大的金属团块。93块普通球粒陨石中有22块样品很新鲜(W1),金属和硫化物几乎很少遭受氧化,61块样品的金属和硫化物遭受明显氧化(W2),仅10块样品的金属和硫化物被强烈氧化(W3)。 |
| 关 键 词： | 陨石 南极陨石化学群 岩石类型 成对陨石 |
CLASSIFICATION OF 100 GROVE MOUNTAINS METEORITES |
|
| Hu Sen,Liu Tao,Feng Lu,Xu Lin,Lin Yangting.CLASSIFICATION OF 100 GROVE MOUNTAINS METEORITES[J].Chinese Journal of Polar Research,2008,20(2):208-218. | |
| Authors: | Hu Sen Liu Tao Feng Lu Xu Lin Lin Yangting |
| Abstract: | A detailed petrographical and mineralogical study is conducted on 100 Grove Mountains(GRV) meteorites.There are four rear types of meteorites including 1 CM2 chondrite(GRV 050179),1 mesosiderite(GRV 050212),1 eucrite(GRV 051523) and 1 ureilite(GRV 052382).GRV 050179 consists of predominant phyllosilicates and poor characterized phases,suggesting strong aqueous alteration and typical of CM2 chondrites.The coarse-grained olivine of GRV 052382 is heavily shocked,recystallized into small euhedral crystals.Diamond(1—3μm) is found in carbonrich assemblages.This meteorite is classified as an ureilite.GRV 050212 contains 12.3 vol% of igneous textures.FeO/MnO weight ratios of low-Ca pyroxenes in both GRV 050212(30.0) and GRV 051523(28.7—30.9) are within the range of HED(Howardites-Eucrites-Diogenites) clan.Of 93 ordinary chondrites,there are 5 unequilibrated ordinary chondrites(GRV 050165,GRV 050189,GRV 050200,GRV 050404 and GRV 053167).According to PMD of fayalite content of olivine,the subtypes of these unequilibrated ordinary chondrites are 3.5,3.4,3.4,3.4 and 3.5,respectively.Other 88 equilibrated ordinary chondrites are classified into H(34) and L(54) groups without LL chondrites.The Grove Mountains meteorites have more L and less H chondrites than other Antarctica meteorite recovered by US.Other 3 small fragments of the meteorites mainly consist of metal with minor silicates.Co content of kamacite and fayalite content of olivine of these fragments are within the ranges of H and L-groups.These metal-rich fragments may be large metal grains from ordinary chondrites.Terrestrial weathering of most ordinary chondrites is weak(W1 for 22 of them) or moderate(W2 for 61 ordinary chondrites),and only 10 ordinary chondrites are severely weathered(W3). |
| Keywords: | |
| 本文献已被 维普 万方数据 等数据库收录！ | |
| 点击此处可从《极地研究》浏览原始摘要信息 | |
| 点击此处可从《极地研究》下载免费的PDF全文 | |