吉南元古宙FCN球粒

产在吉南元古宙石英岩内的宇宙尘是一个宇宙尘系列 ,由 4亚型 4小类组成 :①金属球粒 :a .纯铁球粒 ;b .FCN(Fe、Cr、Ni)球粒 ;②氧化物球粒 :c.普通磁性铁质球粒 ;d .FCS(FeO、Cr2 O3、SiO2 )球粒 ;③玻璃质球粒 ;④氧化物 -金属过渡型球粒。其中FCN球粒和FCS球粒为富铬球粒 ,在地球上属首次发现 ;FCN球粒为天然的奥氏体不锈钢球粒。FCN球粒的发现表明冶金学与地外源事件地球化学有一定联系。富铬宇宙尘的发现 ,预示着地球上可能有铁铬镍型铁陨石存在。

PROTEROZOIC FCN SPHERULES IN SOUTH JILIN PROVINCE, CHINA

It is a cosmic dust series which occurs in Proterozoic quartzite in South Jilin Province of China. Four types and four subtypes are distinguished: (1) metal spherules including pure iron spherules and FCN (natural non\|rust steel) spherules; (2) oxide spherules including Si-Fe oxide spherules (common iron cosmic dusts) and FCN (FeO, Cr\-2O\-3, SiO\-2) spherules; (3) glassy spherules; and (4) oxide metal spherules. FCN spherules commonly contain about 18% Cr, and 5.85% Ni. FCS spherules contain 10.43% to 26.70% Cr\-2O\-3. They both were first discovered in the world. FCN spherules are natural austenic non-rust steel. The event of discovering FCN spherules indicates that there is some relationship between metallurgy and the geochemistry of ultraterrestrial event. The discovery of Cr\|rich spherules predicts the existence of FCN meteorites on the earth surface.