Garnierites and garnierites: Textures, mineralogy and geochemistry of garnierites in the Falcondo Ni-laterite deposit, Dominican Republic

Abstract

Garnierites and garnierites: textures, mineralogy and geochemistry of garnierites in the Falcondo Ni-laterite deposit, Dominican Republic.

Pseudomorphic replacement of diopside during interaction with (Ni,Mg)Cl2 aqueous solutions: Implications for the Ni-enrichment mechanism in talc- and serpentine-type phases

“…For the 400°C experiments with the same Mg-chloride solution, as well as the formation of a continuous inner talc rim, an outer phase of densely packed grains was identified at some isolated regions. These were similar to those observed for the outer Ni-rich rim in Ni-bearing solutions under the same Brindley et al (1979) and the same within lizardite-nepouite series mineral phases from Brindley and Wan (1975) and Villanova-de-Benavent et al (2014) are also plotted for comparison in each diagram. temperature conditions and are closer to a serpentine stoichiometry.…”

“…calculated from electron microprobe data. The (Mg + Ni)/Si ratios of the mineral phases were also compared with natural Ni-rich minerals in either the talc-willemseite (Brindley et al, 1979) or lizardite-nepouite series (Brindley and Wan, 1975;Villanova-de-Benavent et al, 2014) to characterize each mineral phase (Fig. 3).…”

Nickel dispersion and enrichment at the bottom of the regolith: formation of pimelite target-like ores in rock block joints (Koniambo Ni deposit, New Caledonia)

“…It may be affected later on by the reopening of the vein and sealing by red to brownish microcrystalline quartz and clear quartz microfractures. The texture of the kerolite-pimelite filling consists of successive botryoidal growth bands of bluish-green colour similar to those described in Villanova- de-Benavent et al (2014) for type IV garnierite in Dominican Republic ores. Type 2 target-like Ni ores occur exclusively as a layer in thin joints.…”

“…Nickel silicate ores are generally thought to be closely associated with the weathering of peridotite leading to the formation of laterite profile (Trescases 1975;Schellman 1983;Gleeson et al 2003;Freyssinet et al 2005;Villanova-de-Benavent et al 2014). In New Caledonia, the main ore genetic model for Ni ores is based on a single per descensum model where most elements (Mg, Ni and Si) are leached from the surface (Trescases 1975;Troly et al 1979;Pelletier 1983Pelletier , 1996.…”

Fibrous Platinum-Group Minerals in “Floating Chromitites” from the Loma Larga Ni-Laterite Deposit, Dominican Republic

“…Detailed information of the local geology and formation history of the Ni-laterites can be found elsewhere (e.g., [11] and references therein). In general, the weathering profile of the Falcondo mining area is divided into: (i) serpentinized protolith (harzburgite > dunite > lherzolite) at the bottom followed by (ii) saprolite with hydrous Mg-silicate dominated mineralogy (beneath the Mg-discontinuity) and (iii) limonite with Fe-oxide(s) dominated mineralogy at the top (above the Mg-discontinuity) [11][12][13][14].…”