RT Journal Article T1 The Almaden mercury mining district, Spain A1 Hernández, A. A1 Jébrak, M. A1 Higueras, P. A1 Oyarzun Muñoz, Roberto A1 Morata, D. A1 Munhá, J. AB The Almadén district is the largest mercury concentration in the world, with a total content of about 250 000 t of mercury, nearly one third of the known total mercury resources of the Earth. Mercury has been exploited since the Celtic and Roman times, with peak production during the Renaissance and between 1939–1945. The district is hosted by a Paleozoic synclinorium overlying Precambrian rocks. The Paleozoic sequence comprises epicontinental quartz arenite rocks, including black shales and quartzites. Diatremes, alkaline lavas of different composition, and late tholeiitic diabases account for the Ordovician to Devonian magmatism. The tectonic setting of this complex suite corresponds to the intraplate type. The mercury deposits of Almadén can be classified into two main types: type 1, early stratiform type ores characterized by cinnabar deposition on the lower Silurian quartzites (Criadero quartzite; e.g. the Almadén and El Entredicho deposits), and type 2, late discordant orebodies (e.g. Las Cuevas), largely hosted or related to diatremes (the `frailesca rocks') of alkaline basaltic composition. In type 1 cinnabar was deposited during diagenesis, in relation to hydrothermal circulation driven by magmatic activity. Type 2 include a variety of deposits having in common the discordant character of the orebodies (e.g. veins, stockworks, massive replacements), and their wide dispersion along the stratigraphic column, i.e. from Lower Silurian (e.g. Nueva Concepción) to Upper Devonian (e.g. Corchuelo). PB Springer Nature SN 0026-4598 YR 1999 FD 1999-07 LK https://hdl.handle.net/20.500.14352/118316 UL https://hdl.handle.net/20.500.14352/118316 LA eng NO Hernández, A., Jébrak, M., Higueras, P., Oyarzun, R., Morata, D., & Munhá, J. (1999). The Almadén mercury mining district, Spain. Mineralium Deposita, 34(5-6), 539-548. https://doi.org/10.1007/s001260050219 NO Universidad de Castilla La Mancha DS Docta Complutense RD 6 abr 2025