| 距今14亿年低生物量的碳同位素证据 |
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| 引用本文： | 钟华,陈锦石.距今14亿年低生物量的碳同位素证据[J].地质科学,1992,0(2):160-168. |
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| 作者姓名： | 钟华 陈锦石 |
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| 作者单位： | 中国科学院地质研究所, 北京 100029 |
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| 摘 要： | 北京十三陵和天津蓟县两剖面中距今十四亿年海相碳酸盐岩的碳同位素表明,十三陵—蓟县地区当时具有较低的δ13C 值(共分析了152个样品),平均占δ13C=-0.7‰(PDB)。这种较低的δ13C 值很可能具有全球性。原始的海相碳酸盐岩较低的碳同位素组或反映较低的有机碳埋藏速率。有机碳的埋藏速率与当时全球生物量的大小有着密切的关系。磷酸盐岩较低的δ13C 值进一步反映当时较小的全球生物量的存在。每年8.11×108吨有机碳推测是距今十四亿年全球生物量的最小值。
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CARBON ISOTOPE EVIDENCE FOR LOWER BIOMASS ABOUT 1400 MA AGO |
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| Zhong Hua Chen Jinshi.CARBON ISOTOPE EVIDENCE FOR LOWER BIOMASS ABOUT 1400 MA AGO[J].Chinese Journal of Geology,1992,0(2):160-168. |
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| Authors: | Zhong Hua Chen Jinshi |
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| Institution: | Institute of Geology, Chinese Academy of Science, Beijing |
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| Abstract: | In Ming Tomb section (Beijing) and Jixian section (Tianjing),the carbon isotope measurement in marine carbonates of 1400 Ma old show light δ13C values comparative to that of Cenozoic carbonates.The samples studied are basically of original carbon isotope composition, and the lighter δ13C may be of global characteristic at that time.This widely distributed lighter original δ13C was caused bv a lower organic carbon buried rate,and the organic carbon buried rate was correlated to the biomass because of lacking free oxygen in middle Perterozoic atmosphere.The lighter δ13C measured may be thus explained by the existence of lower global biomass.Finally,the biomass produced by organisms before 1400 Ma is estimated,at least 8.11× 103 tons per year. |
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| Keywords: | Carbon isotope biomass Middle Proterozic |
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