Final answer:
The world's largest, commercially developed heavy oil sand deposit is in Alberta, Canada. Alberta's oil sands contain bitumen extracted via strip mining, differing from the mainly underground oil reserves in locations like Saudi Arabia and Venezuela.
Step-by-step explanation:
The world's largest, commercially developed heavy oil sand deposit is located in Alberta, Canada. Known for its vast tar sands, Alberta's oil sands are heavy with bitumen and have been a significant source of fossil fuel. Tar sands deposits contain moist sand and clay mixed with between 1-2 percent of bitumen, which is a thick and heavy petroleum substance rich in carbon. These deposits are extracted primarily by strip mining, which is an intensive process with notable environmental impacts, such as releasing significant amounts of carbon dioxide and methane.
Saudi Arabia and Venezuela are also known to have large oil reserves, but the method of extraction and the type of oil differ. While Venezuela also boasts substantial heavy oil sand deposits, Alberta's have been more commercially developed. Moreover, the Empty Quarter or Rub al Khali, which is the world's largest contiguous sand desert located in Southern Southwest Asia, primarily on the Arabian Peninsula, is another extremely oil-rich region. However, the oil there is not derived from sand but from underground reserves.