Efficient transfer of S and chalcophile metals through the Earth's crust in arc systems is paramount for the formation of large magmatic-hydrothermal ore deposits. The formation of sulfide-volatile compound drops has been recognized as a potential key mechanism for such transfer but their fate during dynamic arc magmatism remains cryptic. Combining elemental mapping and in-situ mineral analyzes we reconstruct the evolution of compound drops in the active Christiana-Santorini-Kolumbo volcanic field. The observed compound drops are micrometric sulfide blebs associated with vesicles trapped within silicate phenocrysts. The compound drops accumulate and coalesce at mafic-felsic melt interfaces where larger sulfide ovoids form. These ovoids are subsequently oxidized to magnetite during sulfide-volatile interaction. Comparison of metal concentrations between the sulfide phases and magnetite allows for determination of element mobility during oxidation. The formation and evolution of compound drops may be an efficient mechanism for transferring S and chalcophile metals into shallow magmatic-hydrothermal arc systems.
U-Pb dating and geochemical analyzes (δ18O, δ13C, Δ47, 87Sr/86Sr and elemental composition) have been applied to fracture-filling calcite veins and host carbonates from the Bóixols-Sant Corneli anticline, which developed along the front of the Bóixols thrust sheet in the Southern Pyrenees. This robust dataset is used to determine: (i) the absolute timing of fracturing and mineralization from fluid flow; (ii) the age and duration of fold evolution; and (iii) the variations and implications of fluid behavior across the anticline, as has been described in the article "Spatio-temporal variation of fluid flow behavior along a fold: The Bóixols-Sant Corneli anticline (Southern Pyrenees) from U-Pb dating and structural, petrographic, and geochemical constraints - Marine and Petroleum Geology (2022) (Muñoz-López et al., 2022). In this new contribution, we present the raw data that have been analyzed and discussed in the related research article and, also, the whole elemental and REE composition of calcite veins and host carbonates that has not been published yet. These data may be used to unravel the age and origin of veins, to understand their sequential evolution in orogenic belts and to compare our results with those obtained in similar settings worldwide.
This brief note presents geochemical data from rock samples from the Cabo Ortegal Complex (NW Spain). The samples belong to acid lithologies within the mainly basic to intermediate granulite unit that have been poorly investigated so far. For this communication, five samples of the migmatites and an amphibolitic enclave within them have been analysed. The whole-rock major and trace-element analyses were accomplished by means of Q-ICPMS. The dataset provides new and useful information relevant to the origin of the acid migmatites and can be used in addition to information from neighbouring lithologies to enhance understanding of the geological evolution of the Western Variscan Belt.
