  Here we describe the ultramafic talc-carbonate unit of the North Pole Dome.
The North Pole Dome (NPD) is located in the centre of the East Pilbara Terrane
(Van Kranendonk et al., 2007). The NPD is a structural dome of bedded,
dominantly mafic volcanic rocks of the Warrawoona and Kelly Groups that dip
gently away from the North Pole Monzogranite exposed in the core of the dome
(Figure 1) (Van Kranendonk, 1999, 2000). Average dips vary from 30 to 60
degrees in the inner part of the dome to about 60 to 80 degrees in the outer
part of the dome (Van Kranendonk, 2000). The North Pole Monzogranite is
interpreted to represent a syn-volcanic laccolith to the Panorama Formation
(Thorpe et al., 1992) and has been estimated to extend approximately 1.5km
below the surface, based on gravity surveys (Blewett et al., 2004). Felsic
volcanic formations are interbedded with the greenstones (Hickman, 1983), and
these are capped by cherts that indicate hiatuses in volcanism (Barley, 1993;
Van Kranendonk, 2006). An overall arc-related model for hydrothermal activity
is favored by Barley (1993), whereas more recent studies have indicated a
mantle-plume model for igneous and hydrothermal activity at the North Pole Dome
(Van Kranendonk et al., 2002, 2007; Smithies et al., 2003; Van Kranendonk and
Pirajno, 2004).
