Mineralium Deposita

, 44:581

Composition and origin of the Çaldağ oxide nickel laterite, W. Turkey

  • Robert Thorne
  • Richard Herrington
  • Stephen Roberts
Note

Abstract

The Çaldağ nickel laterite deposit located in the Aegean region of W. Turkey contains a reserve of 33 million tons of Ni ore with an average grade of 1.14% Ni. The deposit is developed on an ophiolitic serpentinite body which was obducted onto Triassic dolomites in the Late Cretaceous. The deposit weathering profile is both laterally and vertically variable. A limonite zone, which is the main ore horizon, is located at the base of the profile. A hematite horizon is located above the limonite, which in the south of the deposit is capped by Eocene freshwater limestones and in the north by a siliceous horizon. The deposit is unusual in lacking a significant saprolite zone with little development of Ni-silicates. The boundary between the limonite zone and serpentinite below is sharp with a marked decrease in concentrations of MgO from 13 to 1 wt.% over a distance of 2 mm representing the ‘Mg discontinuity’. Ni concentrations within goethite, the main ore mineral, reach a maximum of ~3 wt.% near the base of the limonite zone. Silica concentrations are high throughout most of the laterite with up to 80 wt.% silica in the upper portion of some profiles. The combination of a serpentinite protolith and a high water table at Çaldağ, in association with an aggressive weathering environment in a tropical climate, resulted in the formation of an oxide-dominated deposit. The precipitation of silica may coincide with a change in climate with silica precipitation linked to an increase in seasonality. Additional variations within profile morphology are attributed to transportation during and after laterite development as a result of faulting, pocket type laterite formation and slumping, each of which produces a contrasting set of textural and geochemical features.

Keywords

Çaldağ Nickel laterite Limonite 

References

  1. Bozkurt E, Satir M (2000) The southern Menderes Massif (western Turkey): geochronology and exhumation history. Geol J 35:285–296CrossRefGoogle Scholar
  2. Butt CRM, Nickel EH (1981) Mineralogy and geochemistry of the weathering of the disseminated nickel sulfide deposit at Mt. Keith, Western Australia. Econ Geol 76:1736–1751CrossRefGoogle Scholar
  3. Çağatay A, Altun Y, Arman B (1981) The mineralogy of the Çaldağ lateritic iron, nickel–cobalt deposits. MTA Maden Etut Dairesi Rep 1709, AnkaraGoogle Scholar
  4. Freyssinet P, Butt C R M, Morris R C, Piantone P (2005) Ore-forming processes related to lateritic weathering. Econ Geol 100th Anniversary Volume, pp 681–722Google Scholar
  5. Gleeson SA, Butt CRM, Elias M (2003) Nickel laterites: a review. SEG Newsl 54:10–16Google Scholar
  6. Golightly JP (1981) Nickeliferous laterite deposits. Econ Geol 75th Anniversary Volume, pp 710–735Google Scholar
  7. Kuck PH (2008) Nickel. In: U.S. Geological survey, mineral commodity summaries January 2008 USGS http://minerals.usgs.gov/minerals/pubs/commodity/nickel/#pubs. Accessed 8 Nov 2008
  8. Lelong F, Tardy Y, Grandin G, Trescase JJ, Boulange B (1976) Pedogenesis, chemical weathering and processes of formation of some supergene ore deposits. In: Wolf KH (ed) Handbook of strata-bound and stratiform ore deposits. Elsevier, Amsterdam, pp 92–173Google Scholar
  9. Mosbrugger V, Utescher T, Dilcher D (2005) Cenozoic continental climatic evolution of Central Europe. Proc Nat Acad Sci 102:14964–14969CrossRefGoogle Scholar
  10. Nahon D, Tardy Y (1992) The ferruginous laterites. In: Butt CRM, Zeegers H (eds) Regolith exploration geochemistry in tropical and sub-tropical terrains. Handbook of exploration geochemistry 4. Amsterdam, Elsevier, pp 41–55Google Scholar
  11. Nahon D, Paquet H, Delvigne J (1982) Lateritic weathering of ultramafic rocks and the concentration of nickel in the Western Ivory Coast. Econ Geol 77:1159–1175CrossRefGoogle Scholar
  12. Oliveira BSM, Trescases JJ, Melfi JA (1992) Lateritic nickel deposits of Brazil. Miner Deposita 27:137–146CrossRefGoogle Scholar
  13. Önen AP, Hall R (2000) Sub-ophiolite metamorphic rocks from NW Anatolia, Turkey. J Metamorph Geol 18:483–495CrossRefGoogle Scholar
  14. Schellmann W (1989) Composition and origin of lateritic nickel ore at Tagaung Taung, Burma. Miner Deposita 24:161–168CrossRefGoogle Scholar
  15. Trescases JJ (1997) The lateritic nickel–ore deposits. In: Paquet H, Clauer N (eds) Soils and sediments, mineralogy and geochemistry. Springer, Berlin, pp 125–138Google Scholar
  16. Yılmaz Y, Genç SC, Gürer OF, Bozcu M, Yılmaz K, Karacık Z, Altunkaynak Ş, Elmas A (2000) When did the western Anatolian grabens begin to develop. In: Bozkurt E, Winchester JA, Piper JDA (eds) Tectonics and magmatism in Turkey and the surrounding area, Geological Society Special Publication 173. Geological Society, London, pp 353–384Google Scholar
  17. Zachos JC, Dickens GR, Zeebe RE (2008) An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics. Nature 451:279–283CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Robert Thorne
    • 1
  • Richard Herrington
    • 2
  • Stephen Roberts
    • 1
  1. 1.School of Ocean and Earth Science, National Oceanography CentreUniversity of SouthamptonSouthamptonUK
  2. 2.Mineralogy DepartmentNatural History MuseumLondonUK

Personalised recommendations