Postmelting hydrogen enrichment in the oceanic lithosphere.
Postmelting hydrogen enrichment in the oceanic lithosphere.
复制标题
熔融后大洋岩石圈中的氢的富集度。
DOI：
10.1126/sciadv.abf6071
复制
发表时间：
2021-06
期刊：
影响因子：
13.6
通讯作者：
Monteleone BD
中科院分区：
文献类型：
--
作者：
Le Roux V;Urann BM;Brunelli D;Bonatti E;Cipriani A;Demouchy S;Monteleone BD
地球内部的深海岩石记录了大量的氢富集，这影响了海洋板块的粘度模型。大范围的H2O含量记录在矿物中从挖出的地幔岩一直具有挑战性的解释，因为它往往记录了熔融，交代和扩散过程的组合在空间上孤立的样品。在这里，我们确定的时间变化的H2O含量的辉石从24 Ma的时间序列的深海橄榄岩暴露沿着Vema断裂带（大西洋）。辉石的H2O含量与地壳年龄和辉石化学和增加对年轻和更难处理的橄榄岩。这些变化与熔融后的剩余值不一致，并且与地幔捕虏体中经常观察到的趋势相反。熔融后的氢富集发生在隐交代橄榄岩残留物的低程度，挥发分丰富的熔体的离子扩散，是特别有效的，在最枯竭的橄榄岩。在洋脊下的含水熔体的存在导致广泛的海洋岩石圈中的氢掺入，可能降低地幔粘度相比，干燥的模型。
Abyssal rocks from the Earth interior record extensive hydrogen enrichments that affect viscosity models for oceanic plates. The large range of H2O contents recorded in minerals from exhumed mantle rocks has been challenging to interpret, as it often records a combination of melting, metasomatism, and diffusional processes in spatially isolated samples. Here, we determine the temporal variations of H2O contents in pyroxenes from a 24-Ma time series of abyssal peridotites exposed along the Vema fracture zone (Atlantic Ocean). The H2O contents of pyroxenes correlate with both crustal ages and pyroxene chemistry and increase toward younger and more refractory peridotites. These variations are inconsistent with residual values after melting and opposite to trends often observed in mantle xenoliths. Postmelting hydrogen enrichment occurred by ionic diffusion during cryptic metasomatism of peridotite residues by low-degree, volatile-rich melts and was particularly effective in the most depleted peridotites. The presence of hydrous melts under ridges leads to widespread hydrogen incorporation in the oceanic lithosphere, likely lowering mantle viscosity compared to dry models.
登录
查看更多内容
影响因子：
5.2
作者：
Aubaud, C;Hauri, EH;Hirschmann, MM
通讯作者：
Hirschmann, MM
影响因子：
64.8
作者：
Bonatti, E;Ligi, M;Ottolini, L
通讯作者：
Ottolini, L
影响因子：
18.3
作者：
Brunelli, Daniele;Cipriani, Anna;Bonatti, Enrico
通讯作者：
Bonatti, Enrico
影响因子：
5.3
作者：
Cipriani, Anna;Bonatti, Enrico;Ligi, Marco
通讯作者：
Ligi, Marco
影响因子：
3.9
作者：
Hellebrand, E;Snow, JE;Hofmann, AW
通讯作者：
Hofmann, AW