title of the thesis - Department of Geology - Queen's University

2.2 Local Geology of Creighton Mine
Creighton Mine is located approximately 18 km SW of downtown Sudbury. It is situated on the
southern rim of the Sudbury Igneous Complex in an embayment of sublayer norite, called the
Creighton Embayment (Fig. 2.2).
Fieldwork conducted in summer 2008 at Creighton Mine targeted shears zones exposed
underground as well as faults exposed at the surface surrounding the mine. The underground
study was concentrated between 6600 feet (2012 m) and 7940 feet (2420 m) deep, coinciding with
the 6600 Level (6600L) and the 7940 ramp at the base of the mine. This portion of the mine is
known as the Creighton Deep. Emphasis was placed on levels below 7400 feet (2256 m).
Development is ongoing as the mine strives to reach a depth of 10,000 feet (3048 m; Vale Inco),
as shown in Figure 2.4. In the study area the 400-Orebody is the main mining target (Fig. 2.4A,
2.4B). Above 6600L the orebody follows the footwall-hangingwall contact, which is defined by
the limits of the embayment. In the lowermost levels, the main orebody diverges from the
footwall-hangingwall contact such that it is nearly encased in the footwall (Fig. 2.4A).
Footwall rocks surrounding the embayment (Fig. 2.2; 2.4A) consist of the Creighton Pluton
granite and metavolcanics of the Elsie Mountain Formation (Ames et al., 2005). Granitic footwall
units are medium-grained to coarse-grained, having variable alkali feldspar content and are
massive to weakly foliated. Main mineral constituents include alkali feldspar (50%), often with
alteration to sericite, quartz (40%) and biotite (10%).
Metagabbro is massive and fine to medium-grained (1 mm). It consists primarily of chlorite and
biotite (80%) with quartz (5-10%), plagioclase feldspar (5-10%) and minor amounts (5%) of
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