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从化学成分来看,本区晚渐新世-早中新世火山活动具明显的双模式特征:镁铁质熔岩(体积占优势)包括玄武岩、橄榄中长玄武岩及拉斑玄武质安山岩,而硅质喷出岩主要是钠闪碱流岩、钾质粗面岩及钾质高硅流纹岩。钠闪碱流岩和流纹岩有特征的痕量元素丰度模式:Sr、Ba、Mg、Mn、P、Cr、V 和 Eu 有强烈亏损,而 Rb、Zr、Pb、Nb、Zn、U,Th 等元素则有不同程度地富集。粗面岩的这类特征较不明显。钠闪碱流岩与流纹岩的区别在于它们相对富集较高电荷的阳离子(如 LREE、Nb、Y,特别是 Zr)和 Zn。粗面岩和流纹岩的斑晶矿物组合由下列矿物相构成:钠质斜长石(钠长石—中长石)、钙质歪长石、透长石、石英、铁辉石—富铁钙辉石、铁紫
From the perspective of chemical composition, the Late Oligocene-Early Miocene volcanic activity in this area has obvious dual-mode characteristics: mafic lava (volume dominant) includes basalts, olivine-long basalts and tholeiite andesite, whereas The siliceous extrusive rocks are mainly Napenite flowstone, Potassium-bearing trachyte and Potassium-rich high-silica rhyolite. Pb, Nb, Zn, U, Ni, Pb, Nb, Zn and U are characterized by trace element abundance patterns characterized by Na, Na, , Th and other elements are enriched to varying degrees. This type of trachyte is less obvious. The sodium nadurite stream differs from rhyolite in that they are relatively enriched in higher charged cations (such as LREE, Nb, Y, especially Zr) and Zn. The plagioclase assemblages of the trachyte and rhyolite are composed of the following mineralogical phases: sodium plagioclase (albite-sodicite), calcareous plagioclase, peridotite, quartz, ironiferous-rich Tartaric pyroxene, iron purple