The
Athabasca oil sands (also called the
Athabasca tar sands or
Alberta tar sands) are large deposits of
bitumen or extremely
heavy crude oil, located in northeastern
Alberta,
Canada – roughly centred on the
boomtown of
Fort McMurray. These
oil sands, hosted primarily in the
McMurray Formation, consist of a mixture of crude bitumen (a semi-solid rock-like form of crude oil), silica sand, clay minerals, and water. The Athabasca deposit is the largest known reservoir of crude bitumen in the world and the largest of three major oil sands deposits in Alberta, along with the nearby
Peace River and
Cold Lake deposits (the latter stretching into
Saskatchewan).