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本文叙述了风城富白榴石岩石的微量元素、化学成分、岩石方面的特征。并与国内外含白榴石岩石、特别是与澳大利亚西部钾镁煌斑岩进行了对比。笔者利用八个氧化物变量投图,揭示了含白榴石系列岩石随着SiO_2含量的变化,与其它氧化物变化的特征。经对比,凤城富白榴石岩石的Rb、Y、Zr与乌干达,新南威尔士含白榴石岩石相近,与澳大利亚西部钾镁煌斑岩对比,其差异性表现在本区岩石Cr、Ni、Co含量低,其它不相容元素或低或介于其间。在图解中看出本区岩石MgO、TiO_2低、MgO/K_2O值低、CaO高。投有发现钾镁煌斑岩应有的三种特征性矿物;钾钙板锆石、柱红石、钠透闪石。本区岩石基性程度偏低,其共性表现在二区岩石均富白榴石、均出现碎屑结构、均可受强蚀变、多次爆发。因此,本区白榴石岩可做为寻找钾镁煌斑岩的线索。
This paper describes the trace elements, chemical composition and rock characteristics of Fengcheng fu leprite rock. It is also compared with leucite-bearing rocks at home and abroad, especially with the lamproites of western Australia. The author uses eight oxide variables mapping, revealing the characteristics of the leucite-containing rocks with changes of SiO 2 content and other oxides. By contrast, the Rb, Y, Zr of Fengcheng fullereite rocks are similar to the leucogranite rocks of Uganda and New South Wales. Compared with the lamproites of western Australia, the differences between them are Cr, Ni , Co content is low, other incompatible elements or low or in between. It can be seen from the diagram that the rocks in this area have low MgO, low TiO 2, low MgO / K 2 O and high CaO. There are three characteristic minerals found in the potash-lamprophyres, potassium-calcium-plate zircon, rutile and sodium tremolite. The basicity of the rocks in this area is low, and its common property is that all the rocks in the second area are rich in leftig, both of which have detrital structures and are subject to strong alteration and multiple eruptions. Therefore, the area of white karst rocks can be used as clues to find the lamproite.