 However, its relationship is unknown because the age-location trend does not reach into the Wells Gray-Clearwater area, and the Wells Gray-Clearwater volcanic field is not along trend with the Anahim Volcanic Belt.The Wells Gray volcanics were thought to have formed by crustal thinning and the existence of crustal penetrating structures.More recent studies by volcanologists associated with the Geological Survey of Canada have indicated that the subducted extension of the Nookta Fault may be the primary cause of the alkalic structure of the Wells Gray-Clearwater volcanic field.