The results of about 30 years of exploration and mining activities
and research studies in the Kambalda mining district, Western
Australia, have led to general agreement that the
komatiite-associated Ni sulphide ores formed as a result of
igneous processes (Ross, 1974; Ross and Hopkins, 1975;
Gresham and Loftus-Hills, 1981; Cowden, 1988; Lesher, 1989
and many others). Despite this agreement, the controls on
sulphide supersaturation and concentration of the resulting
sulphide in a limited zone, remain uncertain and controversial. A
major uncertainty is the source of sulphur in the ore deposits.
Two principal sulphur sources have been proposed: 1. komatiite lava/magma (Hudson, 1972; Naldrett, 1973;
Lesher et al, 1981; Cowden, 1988; Foster et at, 1995), and
2. sedimentary material (Groves, Barrett and McQueen, 1979; Lesher, Arndt and Groves, 1984; Lesher, 1989; Lesher and
Campbell, 1993). Resolution of the uncertainty regarding the sulphur source is
required for a complete understanding of the controls on ore
formation, which in turn would significantly impact exploration
strategies in the Kambalda mining district and elsewhere. This paper reviews the constraints on sulphur sources for the
komatiite-associated Ni sulphide ores in the Kambalda mining
district. The focus is on the general characteristics of the ores
and surrounding rocks: individual ore deposits are not described,
though specific examples are noted where appropriate. The
stratigraphic and volcanic settings and geochemical (major and
trace element and isotopic compositions) characteristics of the
ore deposits and surrounding rocks are considered within the
context of the competing sulphur source models, and future
directions of research in the district are noted.