RT Journal Article
T1 The Las Cruces deposit, Iberian Pyrite Belt, Spain
A1 Yesares Ortiz, María Dolores
A1 Sáez Ramos, Reinaldo
A1 Nieto Liñán, José Miguel
A1 Ruiz de Almodóvar Sel, Gabriel
A1 Gómez, Carmelo
A1 Escobar, Juan Manuel
AB The Las Cruces deposit is located at the eastern margin of the Iberian Pyrite Belt (IPB), beneath the Neogene-Quaternary deposits of the Guadalquivir Basin. These sediments covered and preserved the supergene profile somewhat after its generation until its recent discovering. For this reason, the Las Cruces ore deposits, together with Lagoa Salgada in Portugal, are the only known deposits in the IPB that preserve the entire weathering profile, including both the gossan and the enrichment zone. In that sense, the present study provides new data on the IPB ore deposits and their post-Palaeozoic evolution.The primary mineralization consists of massive and semi-massive polymetallic sulfides overlaying a cupriferous and pyritic stockwork. The supergene enrichment extends from the primary zone to gossan and consists of a thick cementation zone characterized by intense replacement of part of the primary sulfides by Cu-rich supergene sulfides.At present, the only economic resource of Las Cruces is the cementation zone, with initial reserves of 17.6 Mt @ 6.2% Cu, but the orebody also includes significant contents of Cu and Zn within the primary mineralization, and Au, Ag, and Pb in the gossan.Mineralogical and geochemical data confirm that the primary mineralization at Las Cruces resembles other IPB deposits in terms of distribution and evolution, however the gossan and cementation zone show an uncommon evolution for this kind of supergene profile. The major singularity that makes the Las Cruces supergene mineralisation noticeably different from others in the IPB or elsewhere resides in its unusual mineralogical composition, mostly comprised of newly-formed siderite, calcite, Fe-sulfides and galena.The genetic model proposed for the Las Cruces deposit includes three main stages: (1) ore genesis and evolution of primary mineralization, which seems to be comparable to other IPB deposits; (2) genesis of Cu-rich secondary mineralization and gossan by weathering, after Miocene exhumation, of the upper part of the massive sulfide deposit, under oxidizing and acidic conditions; and (3) late evolution of supergene profile below the carbonated-rich sediments of the Guadalquivir Basin, with the subsequent change in the redox conditions due to water–rock interaction between the supergene profile and basinal fluids.
PB Elsevier
SN 0169-1368
SN 1872-7360 (electrónico)
YR 2015
FD 2015
LK http://hdl.handle.net/10272/12205
UL http://hdl.handle.net/10272/12205
LA eng
NO Yesares Ortiz, M.D., Sáez Ramos, R., Nieto Liñán, J.M., Ruiz de Almodovar Sel, G., Gómez, C., Escobar, J.M.: "The Las Cruces deposit, Iberian Pyrite Belt, Spain". Ore Geology Reviews. Vol. 66, págs.  25–46, (2015). DOI: 10.1016/j.oregeorev.2014.10.019
NO This research is a contribution to projects P-S Anoxia (CGL2011-30011) and Metodica (CGL2010-21956-C02-02), which are supported by the Spanish Government. The authors thank COBRE LAS CRUCES S.A. for the field assistance, the ongoing collaboration and for the permission to publish data acquired in the exploration stage. We are also grateful to Felipe Gonzalez for their improving language suggestions. The comments and corrections of Eric Marcoux and an anonymous reviewer clearly enhanced the quality of the manuscript.
DS Repositorio Institucional de la Universidad de Huelva
RD 1 jun 2026