华南某些含锡斑岩的岩石化学与地球化学特征*
来源期刊：中南大学学报(自然科学版)1990年第1期
论文作者：胡祥昭 陈惜华
文章页码：9 - 15
关键词：斑岩； 岩石学； 地球化学/华南
Key words：porphyry； petrography； geochemistry/the south of China
摘 要：华南某些含锡斑岩体的化学成分以富硅、贫钙、镁、铁、富碱为特征。其分异指数（DI）一般在90％以上,固结指数低于3,属张裂性花岗岩。根据闻广提出的含锡岩体b值在1～8之间,s值在79～84之间的看法,含锡斑岩的b值和s值均位于锡矿化区间。含锡斑岩体的微量元素以高氟、富铷、贫锶、贫钡为特征。铌钽比值近于1。稀土元素分析表明:∑REE含量较高,相对富集重稀土,铕出现显著负异常。初始锶同位素比值(86Sr/87Sr)i等于0.711～0.716。说明含锡斑岩体的岩浆系由下部地壳物质重熔而成。
Abstract: The characteristics of the chemical composition of the tin-bearing porphyriesare rich in silicon and alkali contents, but poor in calcium, magnesium and ironwith the differentiation index （DI）＞90 and the solidification index （SI）＜3,belonging to tension granite. Based on Wen Guang the b values and the s valuesof tin-bearing bodies respectively vary between 1 and 8 and between 79 and 84,so both values of b and s of the tin-bearing porphyries are in the tin-mineralizationspace. The characteristics of their trace elements are rich in Rb and Fcontents and poor in Sr and Ba. The ratio of Nb/Ta is about 1. As shown bythe REE analysis, REE contents is higher. Compared with the granite of SouthChina, the tin-bearing porphyries have higher HREE contents and an obviousnegative Eu anomaly. The initial ratio of 87Sr/86Sr is 0.711 to 0.716, whichindicates that the tin-bearing porphyries are the product of remelting the lowcrust.
