No slab‐derived CO2 in Mariana Trough back‐arc basalts: Implications for carbon subduction and for temporary storage of CO2 beneath slow spreading ridges
No slab‐derived CO2 in Mariana Trough back‐arc basalts: Implications for carbon subduction and for temporary storage of CO2 beneath slow spreading ridges
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马里亚纳海槽弧后玄武岩中没有板片衍生的二氧化碳：对碳俯冲和缓慢扩张的山脊下暂时储存二氧化碳的影响
DOI：
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
K. Hammerschmidt
中科院分区：
文献类型：
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作者：
C. Macpherson;D. Hilton;K. Hammerschmidt
南马里亚纳海槽特别适合于研究俯冲带的物质平衡，因为从俯冲板片回收的物质通量在该地区的最南端已经减少到可以忽略不计的水平。我们提出了16个弧后玄武岩玻璃的新的He和Ar浓度和同位素数据，并将这些数据与先前公布的CO2和H2O浓度和δ 13 C数据相结合，以探索马里亚纳弧后碳和轻稀有气体的再循环。脱气影响了所有样品，尤其是在含水量更高的样品中，即，其中含有最大的回收成分。脱气历史分为三个阶段：（1）深部脱气，当熔体达到地幔中CO2和稀有气体的饱和时开始，（2）爆发前脱气，在壳幔过渡带储存期间，涉及将额外的CO2添加到气相中，（3）爆发。在第1阶段释放的CO2，至少部分，纳入围岩，随后在第2阶段脱气后期岩浆批次的再活化。重建的3 He/4 He、δ 13 C、CO2/3 He和CO2/40 Ar * 的原始值与洋中脊玄武岩的原始值没有区别。这意味着有可以忽略不计的再循环俯冲碳，氦，或氩到马里亚纳海槽玄武岩的来源。
The Southern Mariana Trough is particularly well suited to study mass balance in subduction zones because the flux of material recycled from the subducted slab has been shown to diminish to negligible levels in the southernmost part of the area. We present new He and Ar concentration and isotopic data for 16 back‐arc basaltic glasses and combine these with previously published CO2 and H2O concentration and δ13C data to explore the recycling of carbon and light noble gases in the Mariana back arc. Degassing has affected all samples and is particularly extensive in more water‐rich samples, i.e., those containing the largest recycled component. The degassing history features three stages: (1) deep degassing which commenced when the melt reached saturation of CO2 and noble gases in the mantle, (2) preeruptive degassing during storage in the crust‐mantle transition zone which involved addition of extraneous CO2 to the vapor phase, and (3) eruption. CO2 released during stage 1 was, at least partially, incorporated into wall rock and subsequently remobilized during stage 2 degassing of later magma batches. Reconstructed parental values for 3He/4He, δ13C, CO2/3He, and CO2/40Ar* are indistinguishable from those of mid‐ocean ridge basalt. This implies that there is negligible recycling of subducted carbon, helium, or argon into the source of Mariana Trough basalt.
影响因子：
5.8
作者：
Collins, S. J.;Pyle, D. M.;Maclennan, J.
通讯作者：
Maclennan, J.
影响因子：
5.3
作者：
Blundy, Jonathan;Cashman, Katharine V.;Witham, Fred
通讯作者：
Witham, Fred
影响因子：
3.5
作者：
Bach, Wolfgang;Klein, Frieder
通讯作者：
Klein, Frieder