engleski

Geological component of terroir of the Nature Park Papuk red wines

Within the Nature Park Papuk, especially on the southern slopes of Mt. Papuk, numerous vineyards are situated. They prograde up finding their place high on the mountain. In spite of the fact that it is already on the high quality level, wine production in the area reflects constant effort of winemakers to improve the production, aiming mostly on the quality and not only on the quantity. The scope of this contribution is to better define the geological component of a terroir of wine related to the specific microenvironment that evolved from metamorphic and igneous rocks. With kind help of the Nature Park Papuk, Veleučilište u Požegi and Vinarija Vlado Krauthaker sampling of rock, soil, grape and wine samples of northernmost and highest vineyards near Vetovo village was performed. The vineyards with grapes that give red wines: Cabernet Sauvignon, Merlot and Shiraz (Veleučilište u Požegi ; VUP) and Syrah (Vinarija Vlado Krauthaker ; KRA) are planted on a thin soil cover laying directly over the pre-Alpine crystalline basement of the Slavonian Mountains. The crystalline rocks found as debris in the vineyards are mostly orthogneisses (Bt+Ms+Pl+Qtz+Grt) and micaschists together with amphibolite (Amp+Pl+Grt+ Qtz+Bt) and metagabbro. Those rocks belong to the oldest dated rocks at Mt. Papuk (528±7 and 465±7 Ma (2σ)) with calc-alkaline peraluminous crustal and mafic rocks as precursors, respectively. They are related to a former active continental marginal setting. The calculated peak P-T metamorphic conditions reach 13 kbar and 670 °C (BALEN et al., 2015). The soil developed on the hill slopes was sampled at two horizons: at 30–35 and 60–65 cm depths. Upper level is characterized with brown colour where sand (and grus) predominates over the clay component. This level is rich in (altered) fragments of metamorphic rocks and quartz. At 60 cm depth, dark brown clay-rich soil comprise limonite substance, metamorphic rocks fragments and agglomerates of altered amphiboles. The basement rocks outcrop through those soil layers. The deeper horizon is more acidic (pH=4.3−4.6 vs. 4.6−4.8 ; exchangeable acidity) which might be ascribed to the anthropogenic influence on the upper soil horizon. Standard minerals typical for amphibolite facies, garnet, amphibole, biotite and feldspar are major hosts of elements important for the wine production. Such elements, liberated from minerals through alteration processes (i.e. production of the “clay minerals” and soil) and biochemical reactions enter the plant, grape and finally end in the wine. All chemical elements measured here are within Croatian legal normative (NN 2/2005 – 4.1.2005). The concentration of elements in the wine correlates well with the soil and mineral/chemical composition of the predominant mineral assemblage in the unaltered rocks. Among them, Ca and Mg demonstrate the best correlation between original rock and red wine. Combination and availability of Fe, Mg, Na, K and Ca together with other factors of wine production have created almost ideal combination for red wine production in this part of Nature Park Papuk.

terroir, metamorphic rocks, Papuk, wine

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