We report petrological and geochronological data for metamafic volcanics and metasediments from the Sargur Greenstone Belt, Western Dharwar Craton (WDC), southern India and discuss the end-Archean metamorphic P–T conditions of the Sargur Greenstone Belt, as well as geotectonic implications of the end-Archean metamorphism in the WDC. The LA-ICP MS zircon U-Pb dating yields a metamorphic age of 2500 ± 20 Ma for the garnet-bearing amphibolite. The garnet-staurolite-kyanite mica schist sample has metamorphic zircon and monazite U-Pb ages of 2443 ± 7 Ma and 2468 ± 10 Ma, respectively, consistent with metamorphic zircon U-Pb ages of 2459 ± 17 Ma and 2455 ± 18 Ma yield by the amphibole-garnet schist samples. The peak mineral assemblage of the garnet-bearing amphibolite is garnet + clinopyroxene + amphibole + plagioclase + quartz + rutile + ilmenite, and that of the metapelitic schist is garnet + staurolite + kyanite + biotite + muscovite + quartz + plagioclase. Phase equilibrium modelling, together with geothermobarometers yield P–T conditions of 7.9–8.9 kbar/681–769 °C and 7.5–9.3 kbar/683–694 °C for the garnet-bearing amphibolite and garnet-staurolite-kyanite mica schist, respectively, corresponding to a medium geothermal gradient of 20–25 °C/km. These data indicate that the Sargur Greenstone Belt has experienced a typical Barrovian-type (amphibolite-facies) metamorphism at ca. 2.50–2.44 Ga. Combined with the previous studies, it is suggested that the Sargur Greenstone Belt was most likely to be formed during 3.35–3.12 Ga and was reworked through four episodes of magmatic-metamorphic events occurred at ca. 3.1 Ga, ca. 3.0 Ga, ca. 2.8–2.6 Ga and ca. 2.5–2.4 Ga. The prominent ca. 2.5–2.4 Ga regional metamorphism is the last stage of the Neoarchean tectono-thermal event in the WDC and thus most possibly indicate accretion-collision of different Archean blocks at ca. 2.5–2.4 Ga and lead to the final cratonization (stabilization) of the whole Dharwar Craton.

我们报告了来自印度南部西达尔瓦克拉通 (WDC) 的萨古尔绿岩带的变镁铁质火山岩和变质沉积物的岩石学和地质年代学数据，并讨论了太古代末变质P-TSargur 绿岩带的条件，以及 WDC 中太古代末变质作用的大地构造影响。LA-ICP MS 锆石 U-Pb 测年得出含石榴石角闪石的变质年龄为 2500 ± 20 Ma。石榴石-十字石-蓝晶石云母片岩样品的变质锆石和独居石U-Pb年龄分别为2443±7 Ma和2468±10 Ma，与变质锆石U-Pb年龄2459±17 Ma和2455±18 Ma产量一致通过角闪石-石榴石片岩样品。含石榴石的角闪石矿物组合为石榴石+单斜辉石+角闪石+斜长石+石英+金红石+钛铁矿，变泥质片岩的峰矿物组合为石榴石+星形石+蓝晶石+黑云母+白云母+石英+斜长石。相平衡建模，连同地温气压计产生P-T含石榴石角闪岩和石榴石-星形石-蓝晶石云母片岩的条件分别为 7.9–8.9 kbar/681–769 °C 和 7.5–9.3 kbar/683–694 °C，对应于 20–25 的中等地温梯度摄氏度/公里。这些数据表明，萨古尔绿岩带在约 2.50-2.44 Ga。结合之前的研究，认为萨古尔绿岩带最有可能形成于 3.35-3.12 Ga 期间，并通过大约 4 次岩浆变质事件重新加工。3.1 Ga，约 3.0 Ga，约 2.8–2.6 Ga 和约 2.5–2.4 Ga。突出的约。2.5-2.4 Ga 区域变质作用是 WDC 新太古代构造热事件的最后阶段，因此最有可能表明不同太古代块体在约 2.5-2。