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Item type:Publication, Timescales of magmatic-hydrothermal activity at the giant San Rafael tin deposit (Peru)(Elsevier B.V., 2025-12-01)Recent research suggests that protracted magmatic activity may play a critical role in forming large metal endowments in magmatic-hydrothermal deposits. Here, we test whether this concept applies to tin systems associated with peraluminous (S-type) granites, focusing on the intrusive complex at San Rafael (Peru) that hosts the world's largest and highest-grade primary Sn deposit (>1.5 Mt of Sn at 3.7 %). We obtained a comprehensive (n = 187) set of high-precision U-Pb zircon dates from granites and mafic rocks that both pre- and post-date the cassiterite Sn ore according to crosscutting relationships. Individual granites exhibit large date dispersions (up to 1.7 Myr), which we evaluate in the context of magmatic and hydrothermal zircon origins, possibility of unmitigated Pb loss, and cryptic inclusion of older zircon cores. By integrating zircon compositions with field observations, we reconstruct 200–400 kyr of magmatic evolution in the crust – from 24.402 ± 0.019 Ma to final emplacement at shallow levels between 24.177 ± 0.004 Ma and 24.027 ± 0.028 Ma. Younger ages found in one sample of the ore-stage cassiterite (23.80 ± 0.25 Ma) and all samples of hydrothermal adularia (∼22.72–22.43 Ma) suggest that the mineralizing fluids were most likely not related to the cooling of the exposed intrusive complex, but instead to one or more younger magma pulses outgassing at depth. The duration of the magmatic build-up prior to Sn mineralization at San Rafael appears significantly shorter than in the largest porphyry copper systems, although we recognize that longer timescales may be resolvable in the unexposed portions of the system. Finally, we compared the metal tonnage and computed volumes of metal-sourcing melt at San Rafael (1.5 Mt of Sn and 77 km3 of melt) with the largest porphyry copper systems in magmatic arcs (112 Mt of Cu and >1000 km3 of melt) to propose that more limited and episodic melt supply, alongside with restricted water availability in (post-)collisional S-type systems may limit the maximum endowments of Sn systems.Scopus© Citations 1 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The Morococala Volcanic Field, Bolivia: Geochemistry and geochronology in the Huanuni district(Elsevier, 2026-08-01)The Central Andes constitute a key natural laboratory for studying the tectono-magmatic response to subduction beneath thick continental crust and the formation of associated ore deposits. In the Bolivian back-arc region, world-class Sn-polymetallic deposits of the Huanuni district are spatially associated with rhyolitic dikes and voluminous peraluminous pyroclastic deposits related to the Morococala Volcanic Field. New geochronological data indicate that the peraluminous rhyolitic dikes in Huanuni were coeval and likely part of the same magmatic plumbing system at ca. 7.0-6.4 Ma, and hence are not associated with the Oligocene-Miocene Sn-polymetallic mineralization (ca. 24 Ma). Mixing models based on Nd-Sr isotopic compositions of the Morococala Volcanic Field, supported by Monte Carlo simulations, suggest crustal contributions of ∼45-70%. These are, in general, concordant with the ∼50:50 mantle-derived melts and continental crust mass balance models proposed for other ignimbrite fields of the Neogene Ignimbrite Province of the Central Andes in the back-arc region (e.g., Los Frailes Volcanic Field and the Panizos, Coranzuli, Vilama, and Ramadas fields within the Altiplano-Puna Volcanic Complex). Mineralogical and geochemical evidence suggests that the associated magmas formed under thick-crustal conditions, with garnet as a residual phase. The voluminous rhyolitic magmatism in the Morococala Volcanic Field likely resulted from hot mantle upwelling induced by slab re-steepening of the subducted slab after a flat-slab episode.