Question: from what time period are most of the rocks in glacier national park
[{'answer': 'Proterozoic', 'provenance': [{'wikipedia_id': '226211', 'title': 'Glacier National Park (U.S.)', 'start_paragraph_id': 26, 'start_character': 479, 'end_paragraph_id': 26, 'end_character': 490, 'bleu_score': 1.0, 'section': 'Section::::Geography and geology.:Geology.\n'}]}, {'provenance': [{'wikipedia_id': '226211', 'title': 'Glacier National Park (U.S.)', 'start_paragraph_id': 26, 'start_character': 0, 'end_paragraph_id': 26, 'end_character': 583, 'bleu_score': 0.9251628191260091, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12814979725198563165}, 'section': 'Section::::Geography and geology.:Geology.\n'}]}]