Structural Deformation and Karst in the Devonian Waterways Formation: Examples from Outcrops along the AthabascaRiver

Summary Structural deformation and karst are frequent phenomena of Devonian outcrops along the Athabasca River in northeastern Alberta. Folds, joints, and, less so, evidence of movement along fractures are ubiquitous; karst features are less common and often subtle. Evidence of paleokarst includes green clay, breccia, and sandstone fill, often in fractures, and less commonly, caves and dissolutionally-enlarged joints. Introduction In the last few decades, structural deformation and karst in Devonian rocks has become an important topic for oil sands production. Fractures, joints, faults, karst, and collapse features can become discharge or recharge zones where exposed by mining operations, creating potential hazards to mining operations. Thus, a better understanding of karst and structural features in the Devonian rock underlying the Cretaceous McMurray Formation is essential to efficient production and environmental stewardship. We encountered many examples of structural deformation and karst during our fieldwork from 2010 to 2013. Here, we present an overview of these features found in outcrops along the Athabasca River.