Archean greenstone belts in the Western Dharwar Craton preserve important clues on Early Earth geodynamics. Here we investigate the ultramafic-mafic metavolcanic rock sequences from the Santaveri Formation of Bababudan greenstone terrane to address the tectonic evolution, mantle dynamics and crustal growth processes of western Dharwar Craton. The ultramafic volcanic rocks are geochemically classified as komatiite-picrite-basanites, whereas the mafic volcanic rocks correspond to magnesian andesite -Niobium-enriched basaltic andesite association. The pristine mineralogy for these ultramafic volcanic rocks is overprinted by tremolite-actinolite-biotite assemblage marking greenschist facies of metamorphism. The komatiites include Al-undepleted, Al-depleted and Ti-enriched types and share overlapping geochemical characteristics with the picrites. The basanites are distinguished as alkaline ultramafic rocks with total alkali content >3 wt% and MgO > 18 wt%. The coherent association of komatiite-picrite-basanite suggests pervasive plume-lithosphere interaction and complies with polybaric melting of a chemically heterogeneous mantle plume through a subduction-modified sub-continental lithospheric mantle at a rifted cratonic margin. Our results substantiate the role of an Archean mantle refertilized by subduction-driven recycling of Mesoarchean supracrustals concurrent with the onset of subduction event at ≥3.2 Ga. The mafic rocks were derived through melting of a hot oceanic slab and mantle hybridization. The xenocrystic zircon grains from komatiite suggest lower crustal inheritance and reworking of basement gneisses by ascending ultramafic melts. The 3177 Ma magmatic age obtained from these zircon grains indicate a Mesoarchean magmatic event in the genesis of the basement gneisses. The emplacement of komatiite-picrite-basanite association and magnesian andesite -Niobium-enriched basaltic andesite lithologies envisages a post 3.1 Ga Neoarchean crustal growth over Mesoarchean protocontinent of WDC. This crust generation episode can be translated in terms of plume-driven bottom-up and subduction-driven top-down tectono-magmatic processes at continental rift and ocean-continent convergence set-up respectively. Geochemical characteristics and petrogenetic aspects suggest that the studied volcanic supracrustals of Bababudan greenstone terrane encapsulate a Neoarchean subduction-collision orogenic system comprising plume-derived komatiite-picrite-basanite and subduction-derived magnesian andesite -niobium-enriched basaltic andesite magmatic sequences tectonically juxtaposed during Neoarchaen (~2.7 Ga) subduction-accretion-collision event.

西部Dharwar Craton的太古代绿岩带保留了有关早期地球动力学的重要线索。在这里，我们研究了巴巴布丹绿岩地层的桑塔维里地层的超镁铁质-镁铁质超火山岩层序，以解决达哈尔克拉通西部的构造演化，地幔动力学和地壳生长过程。在地球化学上，超镁铁质火山岩被归类为科马提岩-黑云母-玄武岩，而镁铁质火山岩对应于镁质安山岩-富铌玄武岩安山岩的组合。这些超镁铁质火山岩的原始矿物学特征是透闪石-阳起石-黑云母组合的印记，标志着变绿的绿片岩相。科马蒂岩包括未脱铝，贫铝和富钛的类型，并且与苦味岩具有重叠的地球化学特征。玄武岩被认为是碱性超镁铁岩，总碱含量> 3 wt％，MgO> 18 wt％。钾镁铁矿-黑云母-玄武岩的连贯联系表明，羽状流与岩石圈之间存在广泛的相互作用，并通过在俯冲克拉通边缘处的俯冲修饰的亚大陆岩石圈地幔，实现了化学非均质地幔羽的多气压熔融。我们的研究结果证实了通过俯冲驱动的Mesoarchean地壳上壳的再利用以及在≥3.2 Ga发生俯冲事件而被精化的太古宙地幔的作用。镁铁质岩石是通过热海平板的融化和地幔杂化而得到的。来自高锰铁矿的异晶锆石晶粒表明，通过增加超镁铁质熔体，降低了地壳遗传和对基底片麻岩的再加工。从这些锆石颗粒获得的3177 Ma岩浆年龄表明在基底片麻岩的成因中存在Mesoarchean岩浆事件。科马蒂岩-苦苣苔-玄武岩结合和镁质安山岩-铌富集的玄武岩安山岩岩性的位点预示了WDC的中初古陆上3.1 Ga的新古生界地壳生长。地壳裂隙的产生可以分别用大陆裂谷和海洋大陆汇聚处的羽状驱动的自下而上和俯冲驱动的自上而下的构造-岩浆过程来解释。