重新评估俯冲带中的碳通量，下沉的物质大多会上升。
Reevaluating carbon fluxes in subduction zones, what goes down, mostly comes up.
作者信息
Kelemen Peter B, Manning Craig E
机构信息
Department of Earth & Environmental Sciences, Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY 10964;
Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095
出版信息
Proc Natl Acad Sci U S A. 2015 Jul 28;112(30):E3997-4006. doi: 10.1073/pnas.1507889112. Epub 2015 Jun 5.
Carbon fluxes in subduction zones can be better constrained by including new estimates of carbon concentration in subducting mantle peridotites, consideration of carbonate solubility in aqueous fluid along subduction geotherms, and diapirism of carbon-bearing metasediments. Whereas previous studies concluded that about half the subducting carbon is returned to the convecting mantle, we find that relatively little carbon may be recycled. If so, input from subduction zones into the overlying plate is larger than output from arc volcanoes plus diffuse venting, and substantial quantities of carbon are stored in the mantle lithosphere and crust. Also, if the subduction zone carbon cycle is nearly closed on time scales of 5-10 Ma, then the carbon content of the mantle lithosphere + crust + ocean + atmosphere must be increasing. Such an increase is consistent with inferences from noble gas data. Carbon in diamonds, which may have been recycled into the convecting mantle, is a small fraction of the global carbon inventory.
通过纳入俯冲地幔橄榄岩中碳浓度的新估计值、考虑沿俯冲地热梯度的水溶液中碳酸盐的溶解度以及含碳变质沉积物的底辟作用，可以更好地限制俯冲带中的碳通量。尽管先前的研究得出结论，约一半的俯冲碳返回对流地幔，但我们发现可能循环的碳相对较少。如果是这样，俯冲带对上覆板块的输入大于弧火山加上扩散排气的输出，并且大量的碳储存在地幔岩石圈和地壳中。此外，如果俯冲带碳循环在5 - 10百万年的时间尺度上几乎是封闭的，那么地幔岩石圈+地壳+海洋+大气的碳含量必定在增加。这种增加与来自稀有气体数据的推断一致。钻石中的碳可能已循环进入对流地幔，但其只是全球碳储量的一小部分。
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