The XL occurrence is located on a northwest-southeast–trending ridge, approximately 9 kilometres north of Braid Creek.
The occurrence lies in the northwest of the Gataga mineral district, in a belt of Paleozoic basinal-facies sedimentary strata known as the Kechika Trough, the southeastern arm of the Selwyn Basin (Exploration and Mining Geology, Volume 1, page 1). These rocks lie just northeast of the Northern Rocky Mountain Trench and belong to Ancestral North America (Geological Survey of Canada Map 1713A). The Gataga mineral deposits are characterized by stratiform sedimentary exhalative barite-sulphide mineralization, best represented in this area by the Driftpile Creek developed prospect (MINIFLE 094K 066), to the southeast.
The XL series of claims are underlain mostly by Ordovician to Devonian rocks (Preliminary Map 38; Assessment Report 9341; Geological Survey of Canada Maps 42-1962, 1712A). The Ordovician to Lower Devonian Road River Group here consists of grey dolomitic siltstone and shale, and dolostone and limestone. More important is the stratigraphically overlying Middle to Upper Devonian Gunsteel Formation (informal name) of the Devono-Mississippian Earn Group, the same unit that hosts the Driftpile Creek deposit, which was dated by fossils. This unit occupies narrow, northwest-trending synclines within the older rocks, and comprises blue-grey weathering, black carbonaceous and siliceous shale and siltstone, chert-pebble conglomerate or sandstone, cherty argillite and radiolarian chert. The shale is locally pyritic. The folds are overturned towards the northeast. At least one large southwest-dipping thrust fault passes through the area, forming the southwestern boundary of the Earn Group; the Cambrian Atan Group forms the hangingwall.
Within the Gunsteel Formation are interbeds of baritic shale, marked by white nodules, laminae or small stringers (approximately 3 centimetres long) of barite, or rarely massive, bedded barite (Assessment Reports 6689, 8172, 9341). This facies may be the same as that which hosts stratiform lead-zinc mineralization elsewhere in this belt, and was the focus of exploration on this property (Assessment Report 8172). High zinc soil anomalies reinforce the correlation; however, no massive sulphide mineralization has been found in place.
Locally, disseminated smithsonite hosted along fractures in chert and zinc mineralization is associated with limonitic gossans.
In 1977, a rock sample (7L62R) from a limonitic gossan assayed 0.67 per cent zinc, whereas chip samples (7W4R and 7W3R) taken several hundred metres to the southwest and southeast of the previous zone, from a zone of disseminated smithsonite yielded 0.13 per cent zinc each over 19.0 and 5.5 metres, respectively (Assessment Report 6689).
Work History
During 1977 through 1979, Zapata Granby Corp. completed programs of geological mapping and geochemical (rock, silt and soil) sampling on the area as the Gran and X properties. In 1980, Noranda Mining and Exploration Inc. completed a program of geological mapping and geochemical (rock and soil) sampling on the property.
In 1995 and 1997, Ecstall Mining Corp. completed programs of geological mapping and geochemical (rock, silt and soil) sampling on the area as the Braid, Thro and Rift claims.
