Nature of Paleozoic Basement of the Catalan Coastal Ranges (Spain) and Tectonic Setting of the Priorat DOQ Wine Terroir: Evidence from Volcanic and Sedimentary Rocks

Abstract

The Paleozoic volcano-sedimentary rocks within the structural basement of the horst-and-graben system of the Catalan Coastal Ranges (CCR) are composed of black shale, volcaniclastic sediments, lava flows, sills and lithocrystalloclastic tuffs. Paleozoic sediments are depleted in high-field strength elements (HFSE) such as Nb, Ta, Zr, Hf and Ti, suggesting their accumulation within the Andean-type active continental margin environment. Volcanic rocks within the Paleozoic CCR sequence belong to shoshonitic and high-K volcanic series and are enriched in Cs, Rb and Ba and depleted in HFSE, which is consistent with their derivation from metasomatized (possibly through deep recycling of pelagic sediments) subduction-related mantle source. The presence of sills (sill-sediment complex) suggests that Paleozoic basement of the CCR was formed within the rifted active continental margin or an arc-back-arc basin system akin to the modern Western Pacific subduction configuration. This complex volcanic terroir hosts world-class wines of the Priorat DOQ region. The presence of framboidal pyrite and magnetite, siderite, sphalerite xenotime, (La–Ce–Nd)-monazite, zircon and baddeleyite, as well as cuprite, tenorite and cupriferous and native silver in volcanic-derived black shale (and consequently in the world-famous “llicorella” soil overlying it) may have had dramatic effects on wine quality and sensory characteristics. These mineral features, together with strong enrichment of Priorat shale in Au, Ag and, to a lesser extent, Pt could have pronounced effects on (1) rates and specific types of chemical reactions; (2) plant metabolism; (3) response to nutrient components and (4) determination of grape flavor. Volcanic wine terroirs, such as the Priorat DOQ region, are special geologic environments for wine growth, capable of producing unique wine aromatic and gustatory characteristics.

Iron–Titanium Oxide–Apatite–Sulfide–Sulfate Microinclusions in Gabbro and Adakite from the Russian Far East Indicate Possible Magmatic Links to Iron Oxide–Apatite and Iron Oxide–Copper–Gold Deposits

“…Another textural type of magnetite in the Bakening adakitic dacite is shown in Figure 7f, where numerous small (about one or two microns in size) euhedral angular-to-roundish magnetite grains are tightly packed into an ovoid-shaped crystalline form along the contact between amphibole and quartz crystals. This magnetite texture very closely resembles framboidal magnetite aggregations in some sedimentary rocks, where the formation of framboids is believed to be a reflection of changes in the overall redox conditions of mineralization [94].…”

Magmatic–Hydrothermal Origin of Fe-Mn Deposits in the Lesser Khingan Range (Russian Far East): Petrographic, Mineralogical and Geochemical Evidence

“…Another rather remarkable silver mineral phase is represented by equant grains or aggregates of non-stoichiometric silver chloride associated with euhedral magnetite grains in a fine-grained chlorite-quartz-magnetite groundmass (Figure 6f). Non-stoichiometric silver chloride, along with acanthite and other silver-bearing sulfides, appears to be relatively common in Paleozoic black shale-volcanogenic formations, arc plutonic root complexes and Cenozoic volcanic rocks from a range of subduction-and non-subduction-related environments, where its origins are linked to the involvement of subduction-related hydrothermal fluids enriched in water, sulfur, and chlorine [99,[102][103][104].…”