Tar sands, also known as oil sands, are a naturally occurring mineral bed found deep within the earth. They are composed of water, sand, clay and bitumens, and can be processed to form petroleum for fueling vehicles, machinery and other types of equipment. While bitumens are found in many different parts of the world, the bitumens in tar sands are extremely heavy and thick. The name “tar sands” is derived from their appearance, though tar is by definition a man-made product. Nearly two-thirds of the world's petroleum resources can be found in the form of tar sands.
Though these sands are found throughout the world, Venezuela and Canada are believed to have the world's largest supplies. The Athabasca Oil Sands in Alberta are the largest tar sands bed in the world, and are also among the most heavily exploited. Because of Canada's large supply of this material, they are by far the largest supplier of oil and petroleum products to the US.
Traditionally, bituminous materials have been used for construction and waterproofing. They were found on tools belonging to ancient peoples, and were extensively used by the Egyptians as part of the mummification process. In fact, the word “bitumen” is derived from an ancient Arab word used to refer to these thick, sticky materials. As the world's oil supplies have dwindled throughout the late 20th and early 21st century, many manufacturers are turning to tar sands as a viable energy source.
Petroleum is typically harvested through a drilling process. Oil wells draw the liquid petroleum to the surface, where it is refined for a variety of uses. Tar sands are extracted using a strip mining technique. Because the bitumens are mixed with the soil, the entire concoction must be extracted and separated before it can be refined.
The use of sand-based sources for oil production has led to major controversy with environmental and political groups throughout the world. As tar sands are extracted, the slurry-like byproducts of this extraction are left behind, covering huge areas of land. Separating and refining the bitumens requires a great deal of energy and water. The land is virtually uninhabitable after tar sands have been collected from the area.
In addition to destroying the land, tar sand production is linked to a number of addition environmental issues that can have far-reaching effects on the earth. Toxic fumes are produces during extraction and refinement. These fumes can cause illness to people, wildlife, and plants. They may also contribute to the greenhouse effect, which is linked to global warming and climate change.