Assertion: crude oil | /r/HasProperty | discovered in the turner valley field
Facets:
value: by the time
type: TEMPORAL
Source sentences:
text: By the time crude oil was discovered in the Turner Valley field, in 1930, most of the free gas cap had been flared off.
text: By the time crude oil was discovered in the Turner Valley field, in 1930, most of the free gas cap had been flared off.