The US Department of the Interior, Bureau of Land Management (BLM), and Argonne National Laboratory, stated the following on their 2012 Oil Shale & Tar Sands Programmatic EIS website, on the page titled "About Tar Sands" (accessed Apr. 10, 2013):
"Tar sands (also referred to as oil sands) are a combination of clay, sand, water, and bitumen, a heavy black viscous oil. Tar sands can be mined and processed to extract the oil-rich bitumen, which is then refined into oil. The bitumen in tar sands cannot be pumped from the ground in its natural state; instead tar sand deposits are mined, usually using strip mining or open pit techniques, or the oil is extracted by underground heating with additional upgrading...
Tar sands are mined and processed to generate oil similar to oil pumped from conventional oil wells, but extracting oil from tar sands is more complex than conventional oil recovery. Oil sands recovery processes include extraction and separation systems to separate the bitumen from the clay, sand, and water that make up the tar sands. Bitumen also requires additional upgrading before it can be refined. Because it is so viscous (thick), it also requires dilution with lighter hydrocarbons to make it transportable by pipelines...
Much of the world's oil (more than 2 trillion barrels) is in the form of tar sands, although it is not all recoverable. While tar sands are found in many places worldwide, the largest deposits in the world are found in Canada (Alberta) and Venezuela, and much of the rest is found in various countries in the Middle East. In the United States, tar sands resources are primarily concentrated in Eastern Utah, mostly on public lands. The in-place tar sands oil resources in Utah are estimated at 12 to 19 billion barrels."
The Council on Foreign Relations stated in its May 7, 2009 report by Michael A. Levi, "The Canadian Oil Sands: Energy Security vs. Climate Change," available at www.cfr.org:
"The Canadian oil sands [tar sands] are a mixture of sand, clay, and bitumen, a highly dense and viscous tar-like form of petroleum. They are concentrated primarily in the Canadian province of Alberta. The International Energy Agency (IEA) estimates that the oil sands contain nearly 1.7 trillion barrels of oil. Proven reserves—those that can be extracted given prevailing and expected economic and operating conditions — were estimated to exceed 170 billion barrels as of January 2008, ranking Canada second only to Saudi Arabia. This is much larger than the resource contained, for example, in the environmentally controversial Arctic National Wildlife Refuge (ANWR), which is estimated to have less than ten billion barrels."
The US DOE National Energy Technology Laboratory stated in its Mar. 27, 2009 report, "An Evaluation of the Extraction, Transport and Refining of Imported Crude Oils and the Impact on Life Cycle Greenhouse Gas Emissions," available at its website:
"Hydrocarbon deposits called bitumen are located in Venezuela and Canada and US... This dense tar-like material is also referred to as oil sands [or tar sands] in Canada and extra - or ultra - heavy crude oil in Venezuela. The bitumen must be mined, separated from the sand and other minerals and either blended with a light oil or upgraded to create a synthetic crude (using heat, pressure, hydrogen and/or catalysts to crack the larger molecules into smaller molecules) so that it can be transported and processed by existing refineries. The GHG [greenhouse gas] emissions associated with the entire process are significantly higher than for extraction of conventional crude oil."