Assertion: obsidian | /r/RelatedTo | domes of volcanic rock
Facets:
value: often
type: TEMPORAL
Source sentences:
text: Obsidian typically forms near the end of a volcanic cycle and is often associated with domes of volcanic rock, such as the hills of Glass Buttes, Oregon.
text: Obsidian typically forms near the end of a volcanic cycle and is often associated with domes of volcanic rock, such as the hills of Glass Buttes, Oregon.