Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

The Kabanga Ni sulfide deposits, Tanzania: II. Chalcophile and siderophile element geochemistry

Maier, Wolfgang D. and Barnes, Sarah-Jane 2010. The Kabanga Ni sulfide deposits, Tanzania: II. Chalcophile and siderophile element geochemistry. Mineralium Deposita 45 (5) , pp. 443-460. 10.1007/s00126-010-0283-x

Full text not available from this repository.

Abstract

The Kabanga deposit constitutes one of the most significant Ni sulfide discoveries of the last two decades (indicated mineral resource 23 Mt of ore at 2.64% Ni, inferred resource 28.5 Mt at 2.7% Ni, November 2008). The sulfides are hosted by predominantly harzburgitic and orthopyroxenitic intrusions that crystallized from magnesian basaltic and picritic magmas. However, compared with other sulfide ores that segregated from such magmas (e.g., Jinchuan, Pechenga, Raglan), most Kabanga sulfides have low Ni (<1–3%), Cu (∼0.1–0.4%), and PGE contents (≪1 ppm), high Ni/Cu (5–15), and low Ni/Co (10–15) and Pd/Ir (2–20). Sulfides with higher metal contents (up to ∼5% Ni, 0.8% Cu, 10 ppm PGE) are found in only one unit from Kabanga North. The observed metal contents are consistent with segregation of magmatic sulfides from fertile to strongly metal-depleted magmas, at intermediate to very low mass ratios of silicate to sulfide liquid (R factors) of approximately 10–400. Sulfide saturation was triggered prior to final emplacement, by assimilation of up to 50% of the total sulfur in the intrusions from sulfide-bearing metasedimentary country rocks. Immiscible sulfide liquid was entrained by the magma and ultimately precipitated in dynamic magma conduits that formed tubular and sill-like mafic–ultramafic bodies characterized by abundant magmatic breccias, highly irregular layering, and frequent compositional reversals. The unusually large degree of crustal contamination and the low R factors render Kabanga an end-member in the spectrum of magmatic Ni sulfide ores.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Ocean Sciences
Subjects: Q Science > QE Geology
Publisher: Springer Verlag
ISSN: 0026-4598
Last Modified: 04 Jun 2017 06:06
URI: http://orca.cf.ac.uk/id/eprint/56484

Citation Data

Cited 7 times in Google Scholar. View in Google Scholar

Cited 14 times in Scopus. View in Scopus. Powered By Scopus® Data

Cited 6 times in Web of Science. View in Web of Science.

Actions (repository staff only)

Edit Item Edit Item