Tauler i Ferré, EsperançaLewis, J. F.Villanova de Benavent, CristinaAiglsperger, Thomas HansProenza Fernández, Joaquín AntonioDomènech Ortí, CristinaGallardo, T.Longo, FranciscoGalí Medina, Salvador, 1949-2020-05-152020-05-152017-070026-4598https://hdl.handle.net/2445/160420Hydrous Mg silicate-type Ni-laterite deposits, like those in the Falcondo district, Dominican Republic, are dominated by Ni-enriched serpentine and garnierite. Recently, abundant Ni-smectite in the saprolite zone have been discovered in Loma Ortega, one of the nine Ni-laterite deposits in Falcondo. A first detailed study on these Ni-smectites has been performed (μXRD, SEM, EPMA), in addition to a geochemical and mineralogical characterisation of the Loma Ortega profile (XRF, ICP-MS, XRD). Unlike other smectite occurrences in laterite profiles worldwide, the Loma Ortega smectites are trioctahedral and exhibit high Ni contents never reported before. These Ni-smectites may be formed from weathering of pyroxene and olivine, and their composition can be explained by the mineralogy and the composition of the Al-depleted, olivine-rich parent ultramafic rock. Our study shows that Ni-laterites are mineralogically complex, and that a hydrous Mg silicate ore and a clay silicate ore can be confined to the same horizon in the weathering profile, which has significant implications from a recovery perspective. In accordance, the classification of "hybrid hydrous Mg silicate - clay silicate" type Ni-laterite deposit for Loma Ortega would be more appropriate.57 p.application/pdfeng(c) Springer Verlag, 2017GeoquímicaMineralogiaNíquelRepública DominicanaGeochemistryMineralogyNickelDominican Republicinfo:eu-repo/semantics/article6677232020-05-15info:eu-repo/semantics/openAccess