The North Pennine Orefield Alston Block has produced approximately 4 Mt Pb, 0.3 Mt Zn, 2.1 Mt fluorite, 1.5 Mt barite, 1Mt witherite plus a substantial amount of iron ore and copper ore from predominantly vein-hosted mineralisation in Carboniferous Limestones. However, a significant proportion of this production (c. 20 %) came from stratabound deposits. Though much is known about the vein-mineralisation, the relationship between the veins and the stratabound mineralisation is not well understood. New petrographic, isotopic and fluid inclusion data derived from samples of stratabound mineralisation allow us to present a unified model that addresses the genesis of both the vein and stratabound styles of mineralisation. The mineralisation can be Bouch et al.Pennine Pb-Zn-Ba-F mineralisation 3

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This study provides an assessment of the potential for stratiform massive sulphide mineralisation in two parts of south-west England, the Central Area between Bodmin Moor and Dartmoor, and North Devon. The Central Area was selected on the basis of its tectonic, stratigraphical and lithological similarities with the Iberian Pyrite Belt (IPB) where numerous volcanogenic massive sulphide (VMS) deposits occur. North Devon is considered prospective on account of its similarities to the Harz Massif in Germany that hosts the major polymetallic sedimentary exhalative (Sedex) deposit at Rammelsberg. More than 60 stratiform mineral occurrences are known in the two areas and previous exploration, including extensive drainage geochemical surveys, geophysical surveying and drilling, has revealed stratiform mineralisation at some localities, including at Egloskerry, near Bodmin Moor, where up to 10% Pb over 4.5 metres was recorded. In North Devon, stratiform mineralisation has been recorded from a borehole at Honeymead Farm, and further evidence of potential is provided by a distinct aeromagnetic anomaly parallel to the regional strike over the upland areas of Exmoor.The potential for the occurrence of stratiform sulphide deposits in North Devon and the Central Area has been assessed by GISbased prospectivity analysis software, Arc-Spatial Data Modeller (Arc-SDM), using knowledge-driven and data-driven modelling techniques. This analysis used both new and legacy multivariate datasets including geophysics (aeromagnetic and gravity), geochemical data, mineral occurrences, and digital 1:50 000 geological linework. This has confirmed known occurrences as well as identifying new targets for stratiform mineralisation.

which led to a complete change in the composition and structure of primary rocks and led to the formation of albite-riebeckite granites with elevated concentrations of rare elements. There is a certain confinement of massifs with such granites to a mobile zone of northwest direction characterised by the most intense manifestation of tectonic dislocations (Stepanov & Bekenova 2009).Study of geological structures showed that riebeckite-albite granites with rare earth and rare metal mineralisation are spatially associated with dome-shaped protrusions of granitoid massifs, whereby the maximum concentration of rare and rare-earth elements are confined to their most apical parts and to apophysis that branch out from the massifs (Stepanov et al. 2011(Stepanov et al. , 2012. A characteristic feature of the Verkhnee Espe massif is a clear zoning in distribution of petrographic varieties of granitoid rocks determined by a changing sequence of paragenetic mineral assemblages, reflecting the evolution of metasomatic processes. The main economic interest concerns the near-contact zone of the Lesser Cupola and ore bodies #1-4 and #6 that concentrate bulk resources of raremetal ores with increased content of Zr, Nb, Th, Y, rare elements and rare earths. The near-contact mineralised zone of the Lesser Cupola combines its northern and north-eastern parts and reveals a well-defined zonation, where rock suites vary from the contact zone to the inner part of the massif in petrographic composition, structural-textural features and concentrations of rare metals and rare earths (Stepanov et al. 2011; Bekenova et al. 2015).Relationship between metasomatites and hornfelsed sedimentary rocks of the roof is characterised by gradual transitions, expressed in: (1) bleaching of rocks near the metasomatites, (2) clear banding, and (3)