The Dodo D-1 is an occurrence of minor barite-lead mineralization, 4.5 kilometres north of Mount Mary Henry on the eastern edge of the mountainous Muskwa Ranges of the Northern Rocky Mountains, 17.5 kilometres south-southeast of the settlement of Summit Lake on the Alaska Highway (Assessment Report 4300, Map 1).
The Dodo D-1 is one of a number of similar MINFILE occurrences lying along a narrow, north-northwest trending belt of mainly Devonian sedimentary rocks. The rocks in this 50-kilometres long, 3-kilometres wide belt are bounded to the west by a steeply-west dipping reverse fault which juxtaposes mostly Middle Proterozoic and Lower Paleozoic rocks. To the east, the belt is flanked by moderately folded, mainly Mesozoic rocks forming the more subdued, Rocky Mountain Foothills. All these rocks belong to Ancestral North America (Geological Survey of Canada Map 1713A).
The Devonian rocks in this belt generally dip steeply east-northeastwards. The most important units are the Middle Devonian Stone and Dunedin formations (Geological Survey of Canada Map 1343A, Memoir 373; Assessment Report 4300). The Stone Formation consists of pale grey, fine-grained, thick-bedded dolostone, dolomitic breccia and dolomitic quartz sandstone. The overlying Dunedin Formation comprises grey, well-bedded, fine-grained limestone, with minor dolostone and siliceous lithologies. Other units in the area include the underlying Silurian to Lower Devonian Nonda, Muncho-McConnell and Wokkpash formations, and the overlying Middle Devonian to Mississippian Besa River Formation.
In the early 1970s and again in the early 1980s, the belt was staked to investigate widespread stratabound barite associated with lead-zinc mineralization in the Dunedin, mainly, and Stone formations (Assessment Reports 4300, 9202). The Dodo D-1 is probably the biggest of four small mineral showings in the Dodo claim group (Assessment Report 4300). Like the others, it occurs in thick-bedded limestone of the Dunedin Formation about 300 metres stratigraphically above the contact with the Stone Formation. Here there are pods of barite and galena, 5 to 10 centimetres thick, forming a zone extending approximately 120 metres along strike. The other showings in the vicinity are similar but smaller, occurring along strike to the south-southeast for about 1 kilometre.
