Asphalt/bitumen also occurs in unconsolidated sandstones known as "oil sands" in Alberta, Canada, and the similar "tar sands" in Utah, US. The Canadian province of Alberta has most of the world's reserves of natural bitumen, in three huge deposits covering 142,000 square kilometres (55,000 sq mi), an area larger than England or New York state. These bituminous sands contain 166 billion barrels (26.4×10^9 m3) of commercially established oil reserves, giving Canada the third largest oil reserves in the world. and produce over 2.3 million barrels per day (370×10^3 m3/d) of heavy crude oil and synthetic crude oil. Although historically it was used without refining to pave roads, nearly all of the bitumen is now used as raw material for oil refineries in Canada and the United States.

What is another term for asphalt?