风城碱性杂岩与有关含金刚石岩类对比的意义

迄今为止,对金刚石矿床的研究已取得了新的进展,国内外学音认为:“金伯利岩不是金刚石矿床的唯一母岩”,并且在碱性杂岩体中发现了许多具有工业价值的金刚石矿床。 通过对比辽宁凤城碱性杂岩与有关含金刚石矿床母岩(主要是钾镁煌斑岩)及其共生岩类的构造背景、岩石类型组合、矿物成分组合及岩石的主元素、微量元素和稀土元素特征,发现本区碱性杂岩体岩石与西澳钾镁煌斑岩很相似,尤其是与西澳白榴石钾镁煌斑岩最为接近,而在岩石类型和矿物组合特点上,又与美国阿肯色碱性岩区金刚石矿床母岩及其共生岩类组合颇为相似,这为我们进一步找寻金刚石矿床提供某些有益的信息。

SIGNIFICANCE OF CONTRASTING BETWEEN FENGCHENG ALKALINE COMPLEX AND RELATED DIAMOND-BEARING ROCKS

Up to now, the study for diamond deposits has been made a brand -new development. The traditional idea, which kimberlite is only mother -rock of diamond deposits, had been denied completely. And many diamond deposits, which are of economic value, have been discovered in the alkaline complex regions.This paper has compared their tectonic background, rock types, mineral association, chemical composition, rare elements and rare - earth element of rocks between Fengcheng alkaline complex and related diamond - bearing rocks (main lamprophyre), and finds that Fengcheng alkaline complex is similar to western Australia lamproite, especially to western Australia leucite lamproite, but from the view of rock -type and mineral association, the Fengcheng alkaline complex is alsovery similar to the mother and associated - rocks of dliomond deposits in Arkansan alkaline rock exposed area.Although, there have no full enough evidences (main characteristic minerals) to affirm the existence of diamond deposit in Fengcheng area, this comparison has very important significance in geological exploration, the similarities give some rather useful information in seeking furtherly diamond deposit in this area.