应用统计法作金刚石找矿中铬铁矿的属性判别

DISCRIMINANT ANALYSIS OF ATTRIBUTE OF CHROMITE IN THE DIAMOND PROSPECTING

根据金伯利岩、钾镁煌斑岩、金刚石包体及其它岩石中铬铁矿电子探针分析成果的统计,发现铬铁矿随着Cr_2O_3含量的降低,其它组分具有四种演化趋势。一般一种岩石中的铬铁矿只有一种演化趋势,唯有金伯利岩、钾镁煌斑岩中有两种演化趋势共存。根据统计资料,采用Cr_2O_3-TiO_2、Cr_2O_3-Al_2O_3和MgO含量,建立了金伯利岩、钾镁煌斑岩中铬铁矿属性判别图,图中三个区间可提供岩石类型、含矿性及保存性三种信息。

Statistical analyses of microprobe analyses of chromite in kimberlite, lamproite, diamond inclusion and so on indicate that there exist four evolutionary trends of composition of chromite in a rock. But there exist two evolutionary trends of composition of chromite in kimberlite oflamproite. Cr2O3-Al2O3-TiO2 and Cr2O3-FeO-MgO diagrams of chromite in kimberlite and lamproite have been drawn based on the statistical analyses. Three fields in the diagrams represent rock type, presence of ore and preservation respectively.