Oil, or Tar, sands are sedimentary rocks made up of oil, clay, water, sand and bitumen. These rocks can be very valuable as they hold large amounts of oil in them. The majority of the world’s oil sand deposits are located in Alberta, Canada and it is estimated that these sands may hold up to 1.6 billion barrels of oil, or nearly 14% of all the world’s oil reserves. The process of removing the bitumen from the rocks requires a lot of work. But in the end it could be very useful as we begin looking for new oil supplies until we can create an efficient alternative source.