Sub-arc mantle enrichment in the Sunda rear-arc inferred from HFSE systematics in high-K lavas from Java

Abstract Many terrestrial silicate reservoirs display a characteristic depletion in Nb, which has been explained some studies by the presence of on Earth with superchondritic Nb/Ta. As one classical example, K-rich lavas from Sunda rear-arc, Indonesia, have invoked to tap such high-Nb/Ta reservoir. To elucidate petrogenetic processes active beneath Java rear-arc and causes for Nb/Ta these lavas, we studied samples somewhat enigmatic Javanese volcano Muria, allow conclusions regarding across-arc variations volcanic output, source mineralogy subduction components. We additionally report data an along-arc sequence Indonesian part arc, extending Krakatoa west islands Bali Lombok east. present major trace element concentrations, Sr–Nd–Hf–Pb isotope compositions, high-field-strength (HFSE: Ta, Zr, Hf, W) concentrations obtained via dilution MC-ICP-MS analyses. The geochemical are complemented melting models covering different compositions slab melts formed at variable P–T conditions. radiogenic frontal arc combination their systematics confirm previously established regional components along arc. Melting show clear contribution sediment-derived component HFSE budget particularly affecting Zr–Hf W. In contrast, more hybrid enriched mantle sources. is particular characterized (up 25) that attributed deep involving overprint garnet–rutile-bearing eclogitic residue. Sub-arc was potentially triggered tear result forced oceanic basement relief ~ 8 Myr ago as confirmed geophysical studies. purported age coincides paucity volcanism, widespread thrusting crust well short-lived nature volcanism time.