Question: where was the largest gold nugget found in california
[{'answer': 'Sierra Buttes', 'provenance': [{'wikipedia_id': '479804', 'title': 'Gold nugget', 'start_paragraph_id': 12, 'start_character': 90, 'end_paragraph_id': 12, 'end_character': 103, 'bleu_score': 1.0, 'section': 'Section::::Largest nuggets.\n'}]}, {'provenance': [{'wikipedia_id': '479804', 'title': 'Gold nugget', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 191, 'bleu_score': 0.732280787930332, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12234710331489963003}, 'section': 'Section::::Largest nuggets.\n'}]}]