Subject	plant root
Predicate	cause
Object	weathering
Modality	Modality Occurrences TBC[mechanical weathering] 2
Polarity	POSITIVE
Plausibility	0.0519
Neighborhood Sigma	0.0528
Local Sigma	0.0553
Example Sentences	Sentence Occurrences Source plant roots cause mechanical weathering 2 Google Autocomplete, Answers.com Questions plant roots cause weathering 1 Google Autocomplete