Sulfur degassing due to contact metamorphism during flood basalt eruptions
Sulfur degassing due to contact metamorphism during flood basalt eruptions
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溢流玄武岩喷发期间由于接触变质作用导致的硫脱气
DOI：
10.1016/j.gca.2013.06.025
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发表时间：
2013
影响因子：
5
通讯作者：
Yallup C
中科院分区：
文献类型：
--
作者：
Yallup C
我们提出了一项研究，旨在量化的潜力，产生富硫气体排放的沉积物的脱挥发分伴随岩床侵位在洪水玄武岩喷发。来自沉积物的富硫气体的潜在贡献可能会大大增加岩浆来源的含硫气体，从而影响区域和全球气候。我们证明，从一个详细的露头规模的研究，硫和总有机碳已被脱挥发分页岩立即周围的3米厚的粗玄岩窗台上的斯凯岛，苏格兰。在页岩接触的几厘米内发生局部部分熔融，产生熔融填充的裂缝。黄铁矿在80厘米接触范围内加热分解，产生富硫气体（H2S和SO2的混合物）和磁黄铁矿。磁黄铁矿由于34 S富集的SO2的损失而显示出32 S富集。磁黄铁矿的进一步分解和氧化导致在接触的几厘米内的赤铁矿和/或磁铁矿。在接触20 cm范围内的倒退冷却和氧化过程中产生硫酸铁。还观察到沉积物因加热而发生的脱碳酸作用，特别是沿着岩床的上部接触面，此处δ 13 C的增加与甲烷气体的损失一致。在页岩中观察到的地球化学和矿物学特征与短寿命侵入体一致，侵位时间<5 h。粗玄岩岩浆中普遍含有黄铁矿，局部硫浓度大于硫化物液体饱和时的硫浓度，这与后期加入硫（可能来自沉积物）一致。我们的研究提供了证据，脱硫，以及脱碳，页岩毗邻火成岩侵入。释放的流体，富含硫和碳，很可能集中在沿着低孔隙流体压力区域沿着边缘的窗台。从沉积物中释放出来的含硫气体如果到达地表，将大大增加喷发的二氧化硫（和硫化氢）产量。这种增强的岩浆硫预算有重要的影响，通过厚，挥发物丰富的沉积序列爆发的大洪水玄武岩喷发的气候影响。
We present a study aimed at quantifying the potential for generating sulfur-rich gas emissions from the devolatilization of sediments accompanying sill emplacement during flood basalt eruptions. The potential contribution of sulfur-rich gases from sediments might augment substantially the magma-derived sulfur gases and hence impact regional and global climate. We demonstrate, from a detailed outcrop-scale study, that sulfur and total organic carbon have been devolatilized from shales immediately surrounding a 3-m thick dolerite sill on the Isle of Skye, Scotland. Localized partial melting occurred within a few centimetres of the contact in the shale, generating melt-filled cracks. Pyrite decomposed on heating within 80 cm of the contact, generating sulfur-rich gases (a mixture of H2S and SO2) and pyrrhotite. The pyrrhotite shows32S enrichment, due to loss of34S-enriched SO2. Further decomposition and oxidation of pyrrhotite resulted in hematite and/or magnetite within a few cm of the contact. Iron sulfates were produced during retrogressive cooling and oxidation within 20 cm of the contact. Decarbonation of the sediments due to heating is also observed, particularly along the upper contact of the sill, where increasing δ13C is consistent with loss of methane gas. The geochemical and mineralogical features observed in the shales are consistent with a short-lived intrusion, emplaced in <5 h. The dolerite magma contains pervasive pyrite and localized sulfur concentrations greater than the sulfur concentration at sulfide liquid saturation, consistent with addition of sulfur (perhaps from sediments) at a late stage. Our study provides evidence for desulfurization, as well as decarbonation, of shales adjacent to an igneous intrusion. The liberated fluids, rich in sulfur and carbon, are likely to be focused along regions of low pore fluid pressure along the margins of the sill. The sulfur gases liberated from the sediments would have augmented the sulfur dioxide (and hydrogen sulfide) yield of the eruption substantially, had they reached the surface. This enhancement of the magmatic sulfur budget has important implications for the climate impact of large flood basalt eruptions that erupt through thick, volatile-rich sedimentary sequences.
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西北赫布里底群岛的侏罗纪沉降历史
DOI：
--
发表时间：
1987
期刊：
影响因子：
--
作者：
N. Morton
通讯作者：
N. Morton
影响因子：
5.8
作者：
G. Desborough;R. H. Carpenter
通讯作者：
G. Desborough;R. H. Carpenter
苏格兰斯凯岛富碳页岩中的火成岩侵入对碳质物质的快速加热：类似于撞击坑中碳的加热？
影响因子：
1.7
作者：
P. Lindgren;J. Parnell
通讯作者：
J. Parnell
利用原位热台 XRD 分析研究不同环境条件下油页岩的矿物反应
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
N. Subasinghe;D. B. Akoiekar;S. Bhargava
通讯作者：
S. Bhargava
古新世岩浆作用在赫布里底盆地海构造演化中的作用：对西北沿海盆地演化的影响
DOI：
--
发表时间：
1992
期刊：
Geological Society Special Publication
影响因子：
--
作者：
R. England
通讯作者：
R. England