About: http://webisa.webdatacommons.org/79790794

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Geology defines a tar sand as a shallow deposit of petroleum mixed with sand, a kind of oil so costly to mine in terms of energy and water usage that engineers have traditionally considered it too uneconomical to exploit.
http://www.w3.org/ns/prov#wasQuotedFrom	pbs.org