Within the Albian upper Mannville of the central Canadian plains there exists a complex of anastomosing channel sandstones which are oriented northwest-southeast and which can be traced for over 300 km. The paleoflow direction was to the north.
The channel sandstones exhibit a complex mineralogy with separate quartzose and lithofeldspathic channel fills present. When viewed within the regional geologic framework of the Lower Cretaceous of western North America, the channel orientation combined with the sandstone petrography indicates that the main sediment source was the Rocky Mountains of the northwest United States. Such a conclusion is in contrast to previous studies of the upper Mannville of the Canadian plains which concluded that the Canadian Cordillera was the major sediment source for an eastwardly prograding clastic wedge.