The WAlps project: Casting new light on scheelite tungsten deposits in the Eastern Alps

Based on considerations such as economic importance and potential challenges to supply security some mineral raw materials are considered “critical”. One prominent example is tungsten, for which supply is strongly dependent on mining in China. One notable exception, representing primary EU-domestic tungsten supply, is the Felbertal scheelite deposit in Austria. Recent investigations regarding ore formation indicate a magmatic-hydrothermal origin of a vein-stockwork scheelite mineralization during the Variscan orogeny, which subsequently experienced significant metamorphic overprint and associated remobilization. Trace element data of scheelite (LA-ICP-MS) demonstrate that primary and metamorphic scheelite have different signatures. Following the discovery of the Felbertal deposit in 1967 substantial greenfield exploration during the 1980s defined many scheelite occurrences in Austria. Different geological settings are known, including strata-bound scheelite mineralization in meta-carbonate and calc-silicate rocks, orogenic Au-W veins, scheelite-bearing metamorphic veins etc. The WAlps project aims to develop assessment criteria for the evaluation of regional tungsten potentials in Austria. This includes field-based investigation of tungsten-bearing geological units in order to evaluate their origin in the context of the current geological-tectonic concept for the Eastern Alps. This will be integrated in a metallogenetic model of Alpine W mineralization. Importantly, we will define the scheelite trace element characteristics from different deposit types to calibrate an exploration tool that can be applied to samples lacking geological context (i.e. stream sediments). In conjunction, we aim to provide a consistent set of geological and geochemical data in order to define areas of high prospectivity for W mineralization in the Easter Alps.