Question: what type of rock is present at grand canyon national park
[{'answer': 'sedimentary rock', 'provenance': [{'wikipedia_id': '621004', 'title': 'Geology of the Grand Canyon area', 'start_paragraph_id': 1, 'start_character': 131, 'end_paragraph_id': 1, 'end_character': 147, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '621004', 'title': 'Geology of the Grand Canyon area', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 601, 'bleu_score': 0.9559054761834711, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18103631991039979974}, 'section': 'Section::::Abstract.'}]}]