The Iberian Pyrite Belt (IPB) is recognized as having one of the major concentrations of volcanogenic massive sulfide (VMS) deposits on Earth. Original resources of about 2000 Mt of massive sulfides have been reported in the province. Recent classifications have considered the IPB deposits as the bimodal siliciclastic subtype, although major differences can be recognized among them. The main ones concern the hosting rocks. To the north, volcanic and volcaniclastic depositional environments predominate, whereas to the south, black shale-hosted VMS prevail. The mineral composition is quite simple, with pyrite as the main mineral phase, and sphalerite, galena, and chalcopyrite as major components. A suite of minor minerals is also present, including arsenopyrite, tetrahedrite–tennantite, cobaltite, Sb–As–Bi sulfosalts, gold, and electrum. Common oxidized phases include magnetite, hematite, cassiterite, and barite. The spatial relationship between all these minerals provides a very rich textural framework. A careful textural analysis reported here leads to a general model for the genetic evolution of the IPB massive sulfides, including four main stages: (1) Sedimentary/diagenetic replacement process on hosting rocks; (2) sulfides recrystallization at rising temperature; (3) metal distillation and sulfides maturation related to late Sb-bearing hydrothermal fluids; and (4) metal remobilization associated with the Variscan tectonism. The proposed model can provide new tools for mineral exploration as well as for mining and metallurgy.

Massive sulphide deposits of the Tharsis Mining District (Iberian Pyrite Belt) are included in a black shaly series that is stratigraphically conformable with the underlying Phyllite–Quartzite Group. Well-preserved palynomorph assemblages have been obtained from this shaly series. The miospore assemblages are assigned to the LN Biozone, indicating a latest Devonian age. This is consistent with the Re–Os age of 348.6 ± 12.3 Ma from both massive sulphides and stockwork mineralization. Palynological and isotopic results from elsewhere in the Pyrite Belt are similar, suggesting that mineralization was synchronous throughout the region.

The Jebilet Massif, located in the southern part of the Moroccan Western Meseta, includes a sequence known As the Sarhlef Series, which comprises mostly black shales with subordinate volcanic rocks and hosts several massive sulfide deposits. Hitherto, the Sarhlef Series has received only scant biostratigraphic attention. Accordingly, a detailed palynological analysis of the shaly Sarhlef strata that embrace the massive sulfide deposit of Draa Sfar, ca. 20km north of Marrakech, is presented herein. The palynoflora consists predominantly of moderately well preserved miospores, together with quantitatively subordinate marine palynomorphs (acritarchs, prasinophyte phyconiata) and scolecodonts. The miospore content, documented systematically herein, comprises 19 genera including 29 species, five of which (Cristatisporites mixtus, Densosporites dissonus, Indotriradites immutabilis, Vallatisporites extensivus and Endoculeospora marrakechensis) are newly established. The Sarhlef miospore assemblage closely resembles those reported from late Visean-early Serpukhovian strata elsewhere in North Africa and adjacent regions. Some similarities are also evident with Western Gondwanan assemblages (viz., from the Parnaiba, Solimoes and Amazonas basins of northern Brazil). The palynological data, in conjunction with published faunal evidence accrued from the overlying lithostratigraphic unit, demonstrate that the age of the black shales of the Sarhlef Series hosting the Draa Star sulfide deposit can be constrained to the late Visean (Asbian); this, moreover, is corroborated by radiometric determinations from associated volcanic rocks.

Well-preserved miospore and organic-walled microphytoplankton assemblages have been recovered from the black shaly series hosting the massive sulphide deposits of Sotiel-Coronada Mine (Iberian Pyrite Belt). The productive samples yielded miospore assemblages representing the uppermost Famennian Retispora lepidophyta–Verrucosisporites nitidus (LN) miospore Biozone of Western Europe. This palynological evidence has important implications for the local geology, constraining the commencement of the volcanic activity and corroborating the previously-defined local tectonic style. Moreover, at regional scale, the new data permit correlation of the black shaly series (which hosts the mineralization in all the sulphide deposits hitherto dated in the region), reinforcing the hypothesis of an anoxic event occurring in the Iberian Pyrite Belt in the latest Devonian times.