Assertion: natural gas | /r/CapableOf | form in place
Facets:
Source sentences:
text: Both petroleum and natural gas formed in places that could contain them: pockets, or reservoirs (reh-zuh-VWARS), in the undersea rock.
text: In other places, natural gas occurs in the tiny pores (spaces) within some formations of shale, sandstone, and other types of sedimentary rock.