Invention is a creation skill, where you use almost every other skill and a great number of items to train. You can do many activities using this skill, such as augmenting items for perks, and making new devices.
Tar Heel is the nickname for a native or resident of North Carolina as well as for the state itself, which is known as the Tar Heel State.
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.