Assertion: lithosphere's crust | /r/HasProperty | generated —submarine mountains
Facets:
value: at the crests of oceanic ridges
type: LOCATION
value: by igneous activity
type: CAUSE
value: continually
type: TEMPORAL
Source sentences:
text: During the early 1960s, the American geophysicist Harry H. Hess proposed that new oceanic crust is continually generated by igneous activity at the crests of oceanic ridges—submarine mountains that follow a sinuous course of about 65,000 km (40,000 miles) along the bottom of the major ocean basins.