| Title | Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans |
| Authors | Shen, Bing Dong, Lin Xiao, Shuhai Lang, Xianguo Huang, Kangjun Peng, Yongbo Zhou, Chuanming Ke, Shan Liu, Pengju |
| Affiliation | MOE, Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China. Peking Univ, Sch Earth & Space Sci, 5 Yiheyuan Rd Haidian Dist, Beijing 100871, Peoples R China. Virginia Tech, Dept Geosci, Blacksburg, VA 24061 USA. Louisiana State Univ, Dept Geol & Geophys, Baton Rouge, LA 70803 USA. Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, Key Lab Econ Stratig & Palaeogeog, Nanjing 210008, Peoples R China. China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing 100083, Peoples R China. Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. MOE, Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China. Shen, B (reprint author), Peking Univ, Sch Earth & Space Sci, 5 Yiheyuan Rd Haidian Dist, Beijing 100871, Peoples R China. |
| Keywords | MAGNESIUM ISOTOPE FRACTIONATION SULFATE REDUCTION ALKALINE ENVIRONMENTS ANAEROBIC OXIDATION MARINE-SEDIMENTS SULFUR-COMPOUNDS NORTH CHINA NEW-MODEL PRECIPITATION OXYGEN |
| Issue Date | 2016 |
| Publisher | NATURE COMMUNICATIONS |
| Citation | NATURE COMMUNICATIONS.2016,7. |
| Abstract | Molar tooth structures are ptygmatically folded and microspar-filled structures common in early-and mid-Proterozoic (similar to 2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks <750 Ma. Here, on the basis of Mg and S isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750Ma brought molar tooth structures to an end. |
| URI | http://hdl.handle.net/20.500.11897/438971 |
| ISSN | 2041-1723 |
| DOI | 10.1038/ncomms10317 |
| Indexed | SCI(E) |
| Appears in Collections: | 地球与空间科学学院 |
