Subject	metamorphic rock
Predicate	be formed
Object	underground
Modality	Modality Occurrences TBC[deep underground] 2
Polarity	POSITIVE
Plausibility	0.9634
Neighborhood Sigma	0.9634
Local Sigma	1.0000
Example Sentences	Sentence Occurrences Source metamorphic rocks are formed underground 6 Google Autocomplete, Answers.com Questions metamorphic rocks are formed deep underground 2 Google Autocomplete, Answers.com Questions