TY - JOUR
T1 - Genesis and mineralogical classification of Ni-laterites, Oman Mountains
AU - Al-Khirbash, Salah
N1 - Funding Information:
This research was funded by Sultan Qaboos University (SQU) Internal Grant (# IG/SCI/ETHS/07/03 ). I acknowledge the partial use of the Dept. of Earth Sciences, the Central Analytical Research Unit (CARU) analytical facilities, and Nancy University for carrying out the EM analyses. Discussion and help from many colleagues are greatly appreciated. The author is also grateful to two anonymous reviewers for their careful revision and suggestions that helped to improve the manuscript.
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - The laterite profiles investigated in the present study developed after the emplacement of a slab of oceanic crust and upper mantle sequence (the Semail ophiolite) onto the East Arabian margin during the Late Cretaceous. The laterites formed as a result of prolonged weathering of the ophiolitic assemblage under tropical to subtropical conditions.Nine laterite profiles have been examined for their Ni potential along a NW-SE segment of the Oman Mountains. The profiles show a vertical succession from bedrock protolith through saprolite, oxide laterite, to clay laterite.A significant enrichment in Ni and Co occurred as a result of the lateritization process. Ni concentrations average 0.63% (Ibra), 0.72% (3 profiles, East Ibra), 0.67% (3 profiles, Al-Russayl), and 0.33% (2 profiles, Tiwi). Electron microprobe analyses showed that goethite, chlorite, kaolinite, serpentine and talc are the main Ni-bearing minerals. This study showed that the Ibra, East Ibra and Tiwi laterites are similar to the other hydrous Mg-silicates (type A) Ni deposits, where nickel-bearing talc (willemseite) or chlorite, and serpentine (nepouite, chrysotile, and antigorite) are the main constituents. Al-Russayl laterite is however, similar to the oxide type (Type C), where most likely the nickel is included in the oxyhydroxides (mainly goethite) minerals.
AB - The laterite profiles investigated in the present study developed after the emplacement of a slab of oceanic crust and upper mantle sequence (the Semail ophiolite) onto the East Arabian margin during the Late Cretaceous. The laterites formed as a result of prolonged weathering of the ophiolitic assemblage under tropical to subtropical conditions.Nine laterite profiles have been examined for their Ni potential along a NW-SE segment of the Oman Mountains. The profiles show a vertical succession from bedrock protolith through saprolite, oxide laterite, to clay laterite.A significant enrichment in Ni and Co occurred as a result of the lateritization process. Ni concentrations average 0.63% (Ibra), 0.72% (3 profiles, East Ibra), 0.67% (3 profiles, Al-Russayl), and 0.33% (2 profiles, Tiwi). Electron microprobe analyses showed that goethite, chlorite, kaolinite, serpentine and talc are the main Ni-bearing minerals. This study showed that the Ibra, East Ibra and Tiwi laterites are similar to the other hydrous Mg-silicates (type A) Ni deposits, where nickel-bearing talc (willemseite) or chlorite, and serpentine (nepouite, chrysotile, and antigorite) are the main constituents. Al-Russayl laterite is however, similar to the oxide type (Type C), where most likely the nickel is included in the oxyhydroxides (mainly goethite) minerals.
KW - Nickel laterite
KW - Oman Mountains
KW - Ophiolite
KW - Weathering
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U2 - 10.1016/j.oregeorev.2014.09.022
DO - 10.1016/j.oregeorev.2014.09.022
M3 - Article
AN - SCOPUS:84918586435
SN - 0169-1368
VL - 65
SP - 199
EP - 212
JO - Ore Geology Reviews
JF - Ore Geology Reviews
IS - P1
ER -