The Dieppe occurrence is located on a north-northeast–trending ridge, in the southwestern headwaters of Yash Creek and approximately 2.4 kilometres south-southeast of Mount Aristotle.
The occurrence is in a region known as the Muskwa Anticlinorium, a major north-northwest–trending structure characterized by moderate folding and thrust faulting. The structure consists of Middle Proterozoic (Helikian) rocks of the Muskwa Assemblage, as well as Paleozoic rocks (Geological Survey of Canada Map 1343A; Geological Society of America, Geology of North America, Volume G-2, pages 111, 639). All belong to Ancestral North America (Geological Survey of Canada Map 1713A). Northeast- to northwest-trending Proterozoic diabase dikes are common in the region.
The occurrence area is underlain by quartzite, dolomitic quartzite, foliated quartz-flooded siltstone and dolomitic carbonate rocks of the Mesoproterozoic Tuchodi Formation which are unconformably overlain by limestone, marble and calcareous rocks of the Cambrian to Ordovician Kechika Group and dolomitic carbonate rocks of the Lower Silurian Nonda Formation. The sedimentary rocks are cut by gabbroic to diabase dikes, ranging in width from 5 to 30 metres.
Locally, an area of abundant siderite and specularite veining is exposed in a zone of hematitic breccia. A large siderite vein breccia, varying from 3 to 8 metres wide and traced for over 60 metres, crosscuts the breccia zone. The vein trends 169 degrees with a dip of 70 degrees to the west. The vein is truncated along strike to the south by an Ordovician conglomerate unit. Host sedimentary rocks consist of sericite, chlorite, and carbonate-altered siltstone. Minor chalcopyrite mineralization, with secondary malachite and azurite, occurs along vein salvages and along a shear zone of two dikes crosscutting the breccia zone.
In 2005, a grab sample (B374360) from the occurrence area assayed 0.357 per cent copper, while another grab sample (B374369) taken approximately 1 kilometre to the southeast yielded 0.934 per cent copper (Assessment Report 28281).
Work History
In 2005, Twenty-Seven Capital Corp. completed a regionally extensive program of geochemical (rock, silt and soil) sampling and a 9002.0 line-kilometre airborne magnetic survey on the area as the Muskwa property.