Abstract Data on the carbon and oxygen isotopic composition of carbonates from the rocks of the Giyani greenstone belt, Kaapvaal craton, South Africa are presented. This belt is immediately adjacent to the Hout River Shear Zone, along which the Southern Marginal Zone (SMZ) of the Limpopo granulite complex is overthrusted onto the Kaapvaal craton. The δ 13 C values are –2.1 and –2.2‰ for carbonates from two metapelite samples, –5.1‰ for a meta ultrabasite sample, and –7.1 and –7.7‰ for two metabasite samples, respectively. The δ 18 О values are 17.1 and 17.5‰ for carbonates from the metapelites, 14.3‰ for carbonates from the metaultrabasite, and 12.9 and 13.0‰ for carbonates from the metabasites. The comparison of the data obtained to the published data on the isotopic composition of carbonates from the rocks of the different greenstone belts indicates both hydrothermal (in the metabasites and the metaultrabasite) and sedimentary (in the metapelites) origins of the carbonate material in the rocks studied. Based on the comparison of these data to δ 13 C of magnesite that formed in ultrabasic granulites during the interaction of the Limpopo complex with the craton, the graphite and fluid inclusions in leucocratic garnet-bearing granitoids that transported fluids, and the carbon isotopic composition of graphite from metapelites of the SMZ, it is concluded that the carbon source was located outside the SMZ and represented a heterogeneous carbonate-bearing lithologies. It could be carbonate-bearing volcanogenic–sedimentary sequences of the greenstone belts of the Kaapvaal craton, which underwent prograde metamorphism during the interaction with the SMZ granulites.

中文翻译：

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绿岩带岩石中碳酸盐的同位素特征作为前寒武纪花岗岩复合体流体可能来源的指标：以南非 Giyani 绿岩带和林波波花岗岩复合体为例

摘要 提供了南非 Kaapvaal 克拉通 Giyani 绿岩带岩石中碳酸盐的碳氧同位素组成数据。该带紧邻豪特河剪切带，沿该带林波波麻粒岩复合体的南部边缘带 (SMZ) 被推倒到 Kaapvaal 克拉通上。来自两个变质泥岩样品的碳酸盐的 δ 13 C 值分别为 –2.1 和 –2.2‰，一个变质超基性岩样品为 –5.1‰，两个变质变质岩样品的 δ 13 C 值分别为 –7.1 和 –7.7‰。来自变泥质岩的碳酸盐的 δ 18 О 值分别为 17.1 和 17.5‰，来自偏铝土矿的碳酸盐的 14.3‰，以及来自变玄武岩的碳酸盐的 12.9 和 13.0‰。将获得的数据与不同绿岩带岩石中碳酸盐同位素组成的已发表数据进行比较，表明岩石中碳酸盐物质的热液来源（在变质岩和变玄武岩中）和沉积物（在变泥质岩中）学习了。根据这些数据与在 Limpopo 杂岩与克拉通相互作用期间在超基性麻粒岩中形成的菱镁矿的 δ 13 C、输送流体的含白晶石榴石花岗岩中的石墨和流体包裹体以及碳同位素组成的比较从 SMZ 变泥质岩中提取石墨，得出结论，碳源位于 SMZ 之外，代表了非均质的含碳酸盐岩性。