碱金属元素对山东蓝宝石结晶的促进作用研究

目的研究碱金属元素对山东蓝宝石结晶的促进作用。方法对山东蓝宝石寄主玄武岩的主量、微量、稀土元素以及蓝宝石包裹体中的主量元素进行分析,再对碱金属氧化物在岩浆网络中的化学行为进行研究。结果晶出山东蓝宝石的母岩浆源于富集地幔的低度熔融,并在蓝宝石结晶前或者结晶过程中与下地壳发生过强烈的壳—幔交互作用,这种交互作用为母源岩浆提供了充足的硅铝质和碱金属氧化物;其中的铝质为蓝宝石的结晶提供了物质基础,而碱金属氧化物则极大地促进了蓝宝石的结晶。结论碱金属元素对山东蓝宝石的结晶有积极的推动作用。

A study on the mechanism that the alkali elements promote the crystal of sapphire

Aim To study the promotion action by alkali elements to the crystal of sapphire.Methods Analyse the main trace and rare earth elements content of Shandong sapphire-hosted basalt and the main elements content of the inclusions in sapphire,then study the chemical action of the alkali elements in magma net.Results Shandong sapphire may have crystalized in a kind of magma which originated from the small-extent melting of enrichment mantle,and this magma must have undergone the violent interaction with under crust before or during the crystal of sapphire,which supplied mother magma a mass of Al,Si and alkali elements.Alkali is perhaps the essential matter for the crystal of sapphire,and the alkali elements can promote the crystal of sapphire on a great extent.Conclusion Alkali elements have the positive effect on the crystal of sapphire.