P. Gumiel and A. Arribas
Antimony deposits in the Iberian Peninsula
Economic Geology and the Bulletin of the Society of Economic Geologists (October 1987), 82(6):1453-1463

Abstract:
The antimony occurrences of the Iberian peninsula are described in terms of mineralogical associations, geochemical features, and chronostratigraphic distribution of the orebodies. A metallogenic and structural classification is proposed. This classification takes into account the mineral assemblages and the form and structure of the deposits, as well as the host-rock lithology. The relationship between the different types of mineralization and the age of the host rocks is discussed, and an attempt is made to establish the time sequence of the metallogenic processes.Eight mineralogical associations are found in the antimony deposits of the peninsula. They are: (1) quartz-stibnite, (2) quartz-stibnite-gold, (3) carbonate-quartz-stibnite-sphalerite-gold, (4) carbonate-quartz-stibnite-galena-silver, (5) quartz-stibnite-sphalerite, (6) quartz-stibnite-scheelite, (7) quartz-stibnite-cinnabar, and (8) quartz-stibnite-copper.The most gold-rich Sb deposits are located in the northwest edge of the Iberian Hercynian belt, in the upper Precambrian-Lower Cambrian basement. The quartz-stibnite-scheelite and quartz-stibnite-cinnabar associations are characteristic of the calcareous formations of Paleozoic age, whereas the quartz-antimony-mercury assemblage occurs only in the lower Carboniferous of the Cantabrian zone.Some Iberian antimony deposits are interpreted to be the result of direct or indirect magmatic processes. In the Lower Ordovician, Silurian-Devonian, and lower Carboniferous, antimony mineralizations are related to preorogenic volcanism, although some vein type deposits are associated with Hercynian granites. Mineralizations related to postorogenic volcanism are of lesser importance. This paper also describes the Spanish strata-bound deposits belonging to the Sb-W-Hg-type association, so far the most important from the economic point of view.