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西藏罗布莎蛇绿岩的地幔橄榄岩和铬铁矿中含有目前世界上已知最富铬的包裹体橄榄石(Cr2O3含量最高达1.49%)和富含铬铁矿出溶体的变形残晶橄榄石。通过对富铬橄榄石产出特征和其中Cr与其他元素相关关系的分析,结合前人的研究,指出铬是以还原态的Cr2+进入橄榄石晶格的,Cr2+可能以占据空位和部分替代Fe2+的方式稳定于富铬橄榄石初始相的晶格中。鉴于前人在罗布莎地幔橄榄岩和铬铁矿中大量超高压强还原相矿物的发现,认为这些富铬橄榄石的初始相可能为形成于地幔过渡带或下地幔的瓦兹利石或林伍德石,富铬橄榄石的产出也反过来证明了罗布莎地幔橄榄岩和铬铁矿中部分物质的深部地幔来源。
The mantle peridotites and chromites in the Tibet Luobusa ophiolite contain the world’s most abundant chromium-bearing olivine (Cr2O3 up to 1.49%) and the deformed residual crystal olive stone. Based on the analysis of the output characteristics of Chromium olivine and the relationship between Cr and other elements, and combining with previous studies, it is pointed out that Cr2 + enters the olivine lattice with reduced Cr2 +, and Cr2 + may occupy vacancies and partially replace Fe2 + The way stable in the chrome olivine initial phase of the lattice. In view of the previous discoveries of a large amount of ultrahigh-pressure-reduced phase minerals in the Robesian mantle peridotites and chromites, it is believed that the initial phases of these chrome olivines may be either the Waszierite or the forest formed in the mantle transitional zone or the lower mantle The output of Woodstone and Chromium olivine also proves the deep mantle source of some materials from the Robesian mantle peridotites and chromites.