The Search for Episodic Remobilization of Basement Faults as a Controlling Mechanism on the Location and Trend of the Joffre and Fenn Linear Cretaceous Sand Bodies

Abstract

The Alberta foreland basin is marked by long (up to 160 km), linear sandbodies that trend in NW-SE and NNW-SSE directions. This long linear nature has brought attention to this area and has initiated a search for a mechanism controlling the position and geometry of the sandbodies. The purpose of this thesis is to test Hart and Flint’s theory that the sandbody trends were controlled by episodic remobilization of basement faults. The larger part of the Cretaceous stratigraphy (of the Alberta Group) is looked at in the area of the Joffre and Fenn fields for consistent thickness variations that would indicate episodic remobilization of basement faults. Underlying basement trends in this area run NE-SW, perpendicular to the trend of the sandbodies. No consistent trends were found in this area during the Cretaceous period. There was a complete lack of NE-SW trends which one would expect to find if NESW basement trends were being remobilized. It follows that remobilization of basement faults, as described by Hart and Plint (1993), were not occurring in this area during the deposition of the Viking sandbodies. Therefore, the Joffre and Fenn linear sandbodies are attributed to sedimentological controls, subsidence and eustatic sea level changes and not to episodic basement movements.