本文選題：東烏旗中鐵隕石 + 橄欖石��； 參考：《極地研究》2013年04期

【摘要】：東烏旗中鐵隕石是1995年在內(nèi)蒙發(fā)現(xiàn)的、為數(shù)不多的降落型中鐵隕石,由金屬-硫化物和硅酸鹽相緊密混合而成。硅酸鹽相由角礫部分(主要為角礫狀橄欖石和輝長巖巖屑)和非角礫部分組成。巖相學(xué)特征、主量元素成分及REE地球化學(xué)特征表明角礫狀橄欖石、非角礫橄欖石和輝長質(zhì)硅酸鹽(輝長巖巖屑和除橄欖石外的非角礫部分)三者可能分別結(jié)晶自不同的巖漿源區(qū)。進一步的分析表明Mg含量非常高的角礫狀橄欖石可能來自一個分異小行星的橄欖巖質(zhì)地幔,非角礫橄欖石和輝長質(zhì)硅酸鹽可能和HED隕石具有相同的母體Vesta小行星。沖擊碰撞導(dǎo)致兩個小行星的物質(zhì)發(fā)生了混合。沖擊作用產(chǎn)生的高溫(約1 200—1 450℃)使得被撞擊小行星表殼玄武質(zhì)和輝長質(zhì)巖石發(fā)生混合重熔,熔體結(jié)晶后形成中鐵隕石的輝長質(zhì)硅酸鹽。該溫度下非角礫橄欖石和角礫狀橄欖石均未發(fā)生重熔。該模型較好地解釋了角礫狀橄欖石、非角礫橄欖石和輝長質(zhì)硅酸鹽三者之間的不平衡現(xiàn)象。
[Abstract]:The Zhongtie meteorite in Dongwu Banner was discovered in Inner Mongolia in 1995. A small number of falling iron meteorites were formed from the close mixing of metal-sulphide and silicate phases. Silicate facies is composed of breccia (mainly breccia olivine and pyroxenite) and non-breccia. The petrographic characteristics, principal element compositions and REE geochemical characteristics indicate that gravelly olivine, Non-breccia olivine and pyrochlastic silicate (pyroxene and non-breccia except olivine) may be crystallized from different magmatic sources respectively. Further analysis shows that the gravelly olivine with very high mg content may come from the peridotite mantle of a differentiated asteroid, and that the non-breccia olivine and pyrochlastic silicate may have the same parent Vesta asteroids as the HED meteorites. The impact and collision resulted in a mixture of material from the two asteroids. The high temperature (about 1 200-1 450 鈩，

本文編號：1810934