Detrital spinels from alpinotype source rocks in middle Devonian sediments of the Rhenish Massif
Detrital spinels from alpinotype source rocks in middle Devonian sediments of the Rhenish Massif
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莱茵地块中泥盆统沉积物高山型烃源岩中的碎屑尖晶石
DOI：
10.1007/bf01820615
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发表时间：
1986
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影响因子：
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通讯作者：
S. Press
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作者：
S. Press
Gummersbach地区(莱茵地块)中泥盆世砂质粉砂岩的铬含量增加(高达675ppm)。铬主要与碎屑状铬铝尖晶石共生。尖晶石具有广泛的化学成分特征，在134个分析的尖晶石颗粒中，超过50%的Cr2O3含量超过50wt%。Al_2O_3含量与Cr2O_3呈负相关，达40wt%。除个别元素外，氧化镁含量均低于氧化亚铁含量，两者呈负相关。从四分之一的颗粒计算出的Fe2O3含量很少超过5wt%。此外，还测定了铬、铝、铁、镁的二氧化钛含量。尖晶石的化学成分表明其来自蛇绿岩套的橄榄岩。物源分析表明，中泥盆世碎屑沉积物的源区位于北部。
Middle Devonian sandy siltstones of the Gummersbach area (Rhenish Massif) show increased Cr contents (up to 675 ppm). The chromium is mainly associated with detrital Cr-Al spinels. The spinels are characterized by a wide spectrum of chemical composition.In more than 50% of 134 analyzed spinel grains the Cr2O3content exceeds 50 wt %. The A12O3content which is negatively correlated to Cr2O3reaches 40 wt %. The MgO contents are, with few exceptions, lower than the FeO contents; both elements are negatively correlated. The Fe2O3contents which were calculated from a quarter of the grains rarely exceed 5 wt %. Besides Cr, Al, Fe, Mg TiO2contents were determined.The chemical composition of the detrital spinels indicates provenance from peridotites of an ophiolite suite.Provenance analysis shows that the source area of the Middle Devonian clastic sediments was situated in the north.