本文關(guān)鍵詞： 西寧隕石 普通球粒隕石 平衡型 L 降落隕石　出處：《極地研究》2013年04期 　論文類型：期刊論文

【摘要】：西寧隕石具有典型的球粒結(jié)構(gòu),球粒輪廓依稀可辨-模糊,基質(zhì)重結(jié)晶程度中-高等,次生斜長石粒度5—40μm,部分顆粒大于50μm。橄欖石和低鈣輝石的化學(xué)成分均一:球粒中橄欖石Fa24.7-25.2,平均Fa24.9,相對標(biāo)準(zhǔn)偏差PMD值0.64%;低鈣輝石Fs21.3-21.9En77.6-78.2Wo0.46-0.57,平均Fs21.5,Fs的PMD值0.84%。說明該隕石已達(dá)熱力學(xué)平衡狀態(tài),為平衡型普通球粒隕石。根據(jù)該隕石結(jié)構(gòu)構(gòu)造特征、金屬含量、礦物化學(xué)組成特征和熱變質(zhì)特征(平衡溫度為778℃),西寧隕石被劃分為L群普通球粒隕石,巖石類型為5型,但已開始向6型過渡。該隕石的沖擊變質(zhì)程度為S3,風(fēng)化程度W0。隕石母體形成之后遭受了沖擊變質(zhì)作用和熱變質(zhì)作用,導(dǎo)致原始球粒破碎、脫玻化和基質(zhì)重結(jié)晶。
[Abstract]:Xining meteorite has typical chondrite structure, the outline of chondrite is discernible and fuzzy, the recrystallization degree of matrix is medium to high, The particle size of secondary plagioclase is 5-40 渭 m, and some particles are more than 50 渭 m. The chemical compositions of olivine and low-calcareopyroxene are homogeneous. The chondrites Fa24.7-25.2, average Fa24.9, relative standard deviation (PMD) 0.64, low calcite Fs21.3-21.9En77.6-78.2Wo0.46-0.57, average Fs21.5Fs PMD 0.84B. it shows that the meteorite has reached a thermodynamic equilibrium state. According to the structural characteristics, metal content, mineral chemical composition and thermal metamorphism (equilibrium temperature of 778 鈩，

本文編號：1541550