Publication Type:

Journal Article

Authors:

Good, D.; Mealin, C.; Walford, P.

Source:

Exploration and Mining Geology, Canadian Institute of Mining, Metallurgy and Petroleum, Volume 18, Number 1-4, p.41-57 (2009)

ISBN:

09641823

Keywords:

Binary alloys, Birds, Copper compounds, Copper deposits, Copper silver deposits, deposits, Faulting, mineralogy, Nickel compounds, Nickel silver, Ore deposit geology, Ores, quartz, Rivers, Serpentine, Silicate minerals, Silver alloys, Silver compounds, Silver deposits, Sulfur compounds, Ternary alloys, volcanic rocks, Volcanoes, Zinc sulfide

Abstract:

The geology of the Ore Fault Ni-Cu deposit has been reinterpreted in the light of recent studies of the geology of the Neoarchean Bird River Sill Complex and the occurrence of economic Ni-Cu and Zn-Cu-Ag mineralization. The Ni-Cu sulfides are hosted by the lower of two parallel NNW-trending and moderately W-dipping mafic-ultramafic intrusions related to the Bird River Sill Complex. The bodies intruded a bimodal volcanic suite consisting of weakly deformed mafic flows and felsic pyroclastic rocks. The mafic volcanic rocks are geochemically related to the MORB-type rocks of the Lamprey Falls Formation, and the felsic volcanic rocks are related to arc-type rocks of the Peterson Creek Formation. The original pyroxene- and olivine-dominated mineralogy of the sills has been replaced by variable serpentine-amphibole-talc-carbonate assemblages. The Ni-Cu sulfide assemblage exhibits textures and geochemical signatures typical of orthomagmatic sulfide mineralization. The sulfide minerals are associated with cumulate layers of magnetic ferrochromite that range in thickness from a few to tens of centimeters. A later event of Zn-Cu-Ag sulfide mineralization associated with quartz veining and garnet-chlorite alteration along a fault that strikes north, dips vertically, and cuts all rock types. The mineralized fault is cut by the NE-trending Peterson Creek shear zone. Where the Ni-Cu and Zn-Cu-Ag mineralized zones intersect, remnant magmatic features such as amphibolite or cumulate ferrochromite bands occur within quartz veins or local chlorite alteration. The mixed zones contain a very unusual polymetallic assemblage of Ni, Cu, Zn, Ag, and platinum group elements (PGE). 2009 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved.

Notes:

Compilation and indexing terms, Copyright 2018 Elsevier Inc.<br/>20123115284984<br/>Geochemical signatures<br/>Mineralized zone<br/>Ni-Cu-PGE<br/>Platinum group elements<br/>Polymetallic<br/>Pyroclastic rocks<br/>Sulfide mineralization<br/>Talc carbonates