Question: where do some rift valleys form along the oceanic ridge system
[{'answer': 'The Mid-Atlantic Ridge', 'provenance': [{'wikipedia_id': '145705', 'title': 'Mid-Atlantic Ridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 22, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '145705', 'title': 'Mid-Atlantic Ridge', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 307, 'bleu_score': 0.925510115564336, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15237208787619374575}, 'section': 'Section::::Notable features.\n'}]}]