The principal ore-bearing zone in the Ambrosia Lake area of the Grants uranium district is the Westwater Canyon Member of the Morrison Formation of Jurassic age. This is also one of the major artesian aquifers in the region. Significant declines in the potentiometric head within the aquifer have been recorded, and digital modeling shows that declines may locally approach 3,000 ft (900 m) in the vicinity of a mine. Loss of potentiometric head in the Westwater Canyon Member has resulted in the interformational migration of groundwater along fault zones from overlying aquifers of Cretaceous age. This has resulted in local deterioration in chemical quality of the groundwater.

End_of_Article - Last_Page 690------------