The Thirteen Creek showing is 74.7 kilometres southeast of Prince Rupert and 63.6 kilometres southwest of Kitimat.
The Ecstall belt is a north-northwest trending, high-grade metamorphic belt bounded by the elongate mid-Cretaceous Ecstall pluton on the west and the Paleocene Quottoon pluton on the east (Map 2). Gareau (1991a) divided stratified rocks of the belt into four principal units: metavolcanic rocks, metasedimentary rocks, quartzite and layered gneiss.
A 30-centimetre-wide, 100-metre-long chert bed with pods of massive pyrite-chalcopyrite mineralization occurs in quartz-biotite- chlorite schist. A grab sample taken at 640 metres elevation assayed 8.06 per cent copper, 0.53 per cent zinc, 350 grams per tonne silver, and 2.4 grams per tonne gold (Assessment Report 15488). Several boulders found within the cirque contain pyrrhotite-pyrite- chalcopyrite-galena mineralization.
A drill hole, 350 metres to the north intersected a 10-centimetre section of argillite with sphalerite and pyrite containing 0.98 per cent zinc.
A 200-metre-wide succession, containing disseminated and stringer copper mineralization and local banded zinc mineralization is reported (George Cross Newsletter #26, February 8, 1994).
A belt of vertically dipping sericitic quartzofeldspathic gneiss 150 metres wide and 2.5 kilometres long contains widespread disseminated chalcopyrite, minor pyrite and traces of bornite. The longest chip sample assayed 0.20 per cent copper over 119 metres; the highest-grade sample returned 0.65 per cent copper over 7.5 metres (Exploration and Mining 1994).
The Thirteen Creek prospect crops out on cliffs on the south side on the Thirteen Creek cirque at 640 metres elevation. The showing is a 30-centimetre-wide chert bed which hosts pods of massive pyrite-chalcopyrite (Hassard et al., 1987b, p.26 and Figure 7). The chert unit has been traced for 100 metres along strike. A grab sample assayed 8.05 per cent copper, 0.53 per cent zinc, 350 grams per tonne silver and 2.4 grams per tonne gold (Hassard et al., 1987b).
The Thirteen Creek showing was included in the 2019 airborne VTEM survey over Kingfisher Resources Ltd.'s Ecstall property. The airborne survey was aimed at detection of structures and/or conductors related to potential Cu-Au-Zn-Ag VMS-style mineralization (Assessment Report 39155).
