The provenance of Devonian sandstones of the Padeha Formation (Fm.), Eastern Alborz in Iran, has been investigated by standard heavy-mineral analysis and tourmaline and rutile geochemistry. Heavy-mineral assemblage is dominated by the ultra-stable tourmaline, zircon, and rutile, while unstable species are completely absent. The Padeha Fm. sandstones show a very high value of zircon-tourmaline-rutile index signalizing either strong weathering in source area(s) or their recycled origin in older Early Palaeozoic formations. Detrital tourmaline shows predominantly dravitic, lesser Mg-foititic, and uvitic compositions and metasedimentary origin. Metapelitic source is also indicated by rutile geochemistry. Temperature estimates according to Zr-in-rutile thermometry show a wide range from 519 to 872°C and indicate the presence of low- to upper-amphibolite and granulite facies metapelitic rocks. Based on chemical composition of detrital tourmaline and rutile, we inferred that the crystalline basement rocks of the Arabian–Nubian Shield were potential primary sources for the Padeha Fm. deposits. Shape of tourmaline and rutile as well as their microtexture surface features indicate long-distance transport, storage, and recycled history.

中文翻译：

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伊朗北部 Alborz 山脉 Padeha 组早-中泥盆世砂岩中的电气石和金红石地球化学

已通过标准重矿物分析以及电气石和金红石地球化学研究了伊朗东部阿尔伯兹帕德哈组 (Fm.) 泥盆纪砂岩的来源。重矿物组合以超稳定的电气石、锆石和金红石为主，而不稳定的物种则完全不存在。帕德哈 Fm。砂岩显示出非常高的锆石-电气石-金红石指数值，表明源区的强烈风化作用或它们在较早的早古生代地层中的再循环起源。碎屑电气石显示主要为水镁石、较少的镁铁质和葡萄质成分和变沉积成因。金红石地球化学也表明了变泥质来源。根据金红石中 Zr 测温法估计的温度范围为 519 至 872°C，表明存在低至上角闪岩和麻粒岩相变泥质岩。根据碎屑电气石和金红石的化学成分，我们推断阿拉伯-努比亚地盾的结晶基底岩是帕德哈组的潜在主要来源。存款。电气石和金红石的形状及其微纹理表面特征表明了长途运输、储存和回收的历史。