IOCAS-IR  > 海洋地质与环境重点实验室
深海流体-岩石相互作用的拉曼光谱原位分析方法及应用
席世川
Subtype博士
Thesis Advisor阎军
2021-05-11
Degree Grantor中国科学院大学
Place of Conferral中国科学院海洋研究所
Degree Name理学博士
Keyword激光拉曼光谱 原位探测 流体岩石相互作用 热液 冷泉
Abstract

以热液、冷泉为代表的深海极端环境广泛存在着流体与热液硫化物、自生碳酸盐岩、基岩等岩石的相互作用,不仅记录了系统内流体的活动历史,同时也为化能合成生物群落提供了物质和能量来源。由于深海极端环境的流体组分复杂、易受温度和压强影响,过去主要通过岩石样品的地化分析反演流体的活动历史,很难实现流体-岩石相互作用的原位探测。流体-岩石相互反应的本质是流体和矿物界面的相互作用,而关于流体-矿物界面相互作用的原位探测很少有报道。激光拉曼光谱技术具有分析简单、无损、无需样品处理、原位探测等优点,可以用于开展流体-岩石相互作用原位探测的研究。为实现激光拉曼光谱技术在流体-岩石相互作用的原位探测,作者主要做了以下工作:
(1)在实验室开展流体-岩石相互作用实验需要相应的深海环境模拟装置。因此,作者研制了可与共聚焦显微激光拉曼光谱探测系统联用的显微可视化低温/高温高压反应舱,温度和压强覆盖了深海热液、冷泉环境,为开展深海极端环境流体与岩石相互作用的原位探测提供了设备保障。
(2)为了定量研究流体-岩石相互作用过程,本研究基于激光拉曼光谱技术对流体-岩石相互作用中的关键组分建立了一系列定量分析模型。本文通过研制的深海极端环境模拟系统分别建立了热液HSO4-_SO42-流体中HSO4-和SO42-拉曼定量分析模型、SO42-的主峰频移与温度的定量关系式以及H2O的O-H伸缩振动模式所对应的拉曼峰频移与盐度的定量模型。基于一张拉曼光谱可获取流体中多种组分的含量和参数,从而可实现深海极端环境流体的原位探测以及原位监测流体与岩石相互作用过程的流体组分的变化。
(3)激光拉曼光谱技术能反映矿物的组分和结构,但是激光也会造成矿物热氧化蚀变。为了探索激光热效应在流体-岩石相互作用中对矿物组成和结构是否造成的影响,本研究基于研制的显微可视化反应舱在流体-矿物界面处开展激光拉曼光谱技术的原位观测,分析流体在矿物热氧化过程中的作用。作者通过控制激光功率改变激光光斑所在区域的热量,对深海极端环境代表性的含硫矿物和文石进行热氧化过程的研究。根据前线轨道理论,黄铜矿更容易发生热氧化,并最终氧化为赤铁矿。与过去的研究相比,黄铁矿热氧化时先转化为白铁矿,最终氧化为赤铁矿,细化了黄铁矿的热氧化过程。铜蓝则热氧化为辉铜矿。重晶石很难热氧化生成新物质,但是晶体的无序度会增加。文石由于透明度高,不易吸收激光产生的热量,而不会发生热氧化。流体的加入可以抑制硫化物的热氧化蚀变,这可能与水的高散热能力或者流体-矿物界面处的吸附反应有关,对研究流体-矿物界面处的反应具有启示意义。
(4)激光拉曼光谱技术针对流体各组分已经建立了一系列定量分析模型,并对矿物组分和结构进行了分析。本研究以橄榄石和水作为初始反应物,对本文建立的流体-岩石相互作用的拉曼分析技术体系进行了实验室内的综合应用。蛇纹石化反应作为一种典型的水岩反应,在深海超基性岩热液系统和泥火山区域广泛存在,为深海化能合成生态系统提供了重要的物质和能量来源。蛇纹石化反应的初步原位监测结果表明随着反应的进行,在流体-岩石界面处出现了橄榄石的拉曼峰宽化的现象,表明橄榄石的结构遭到破坏,这可能是由于橄榄石矿物晶体声子间相互作用增强,为深入研究蛇纹石化过程中橄榄石-流体界面处橄榄石的结构变化和流体的相互作用提供了线索。
(5)在实验室内模拟系统综合应用的基础上,本文最终将建立的流体-岩石相互作用的拉曼分析方法进行了深海原位应用:在南海北部台西南盆地活跃冷泉区域Site F首次开展了大规模的流体与自生碳酸盐岩相互作用的原位探测。本研究发现随着生物群落密度的降低,文石晶体结构逐渐破坏以及含量降低。Site F不同位置流体的原位定量分析结果表明繁茂生物群落内部发生的甲烷厌氧氧化反应和甲烷氧化反应等生物地球化学反应会形成低盐度和低硫酸根的流体。由于盐效应,这些内部流体会抑制自生碳酸盐岩的侵蚀,反之裸露的自生碳酸盐岩更容易受到高盐度、高硫酸根海水的侵蚀风化,这为研究自生碳酸盐岩的演化提供了新的认识。最后结合大量的原位拉曼光谱和实验室XRD、SEM分析结果,作者建立了Site F区域生物地貌、矿物结构和含量、流体的分布模式图,为生态系统的研究和流体-岩石相互作用的原位探测提供了参考。

Other Abstract

The interaction between fluid and hydrothermal sulfides, authigenic carbonate rocks and other rocks in the extreme environment of deep sea that represented by hydrothermal and cold seeps, not only records the history of fluid activity in the system, but also provides material and energy sources for the chemical synthetic biota community. Due to the complexity of fluid components and the susceptibility to temperature and pressure in the deep-sea extreme environment, it is difficult to achieve in situ detection of fluid-rock interaction based on the inversion of fluid activity history based on geochemical analysis of rock samples. The essence of fluid-rock interaction is the interaction between fluid and mineral interface, but there are few reports on fluid-rock interaction in situ. Laser Raman spectroscopy has many advantages, such as simple analysis, non-destructive analysis, no sample handling and wide application range, which can be used in studying the in situ detection of fluid-rock interaction. In order to realize in situ detection of fluid-rock interaction by laser Raman spectroscopy, the author has mainly done the following works:
(1) To conduct fluid-rock interaction experiments in the laboratory, corresponding deep-sea environment simulation devices are required. Therefore, the author developed visualized low temperature/high temperature and high pressure reaction chambers, which can be used in conjunction with the confocal microscopic laser Raman spectroscopy detection system. The temperature and pressure cover the deep-sea hydrothermal and cold seep system, which provides equipment support for the in-situ detection of the interaction between fluid and rock in the extreme deep-sea environment.
(2) In order to quantitatively study the fluid-rock interaction process, a series of quantitative analysis models for the key components in the fluid-rock interaction were established based on laser Raman spectroscopy. In this paper, the HSO4- and SO42-Raman quantitative analysis models in hydrothermal HSO4-—SO42- fluid, the quantitative relationship between the Raman shift of main peak of SO42- andtemperature, and the quantitative model of Raman shift and salinity corresponding to the O-H stretching vibration mode of H2O were established respectively by using the simulation system of deep-sea extreme environment.
(3) Laser Raman spectroscopy can effectively reflect the composition and structure of minerals, but laser may also cause thermal oxidation or alteration of minerals. In order to explore the influence of laser thermal effect on mineral composition and structure in the fluid-rock interaction, this study carried out in situ laser Raman spectroscopy observation at the fluid-mineral interface based on the developed micro-visualized reaction chamber, and analyzed the role of fluid in mineral thermal oxidation process. The thermal oxidation process of sulfur minerals and aragonite in extreme deep-sea environments was studied by controlling the laser power to change the heat in the area where the laser spots were located. According to frontier orbit theory, chalcopyrite is more likely to undergo thermal oxidation and eventually oxidize to hematite. Compared with previous studies, pyrite is first converted to marcasite and finally oxidized to hematite during thermal oxidation, which refined the thermal oxidation process of pyrite. Covellite is thermally oxidized to chalcocite. Barite is difficult to be thermally oxidized to form new substances, but the disorder of crystals increases. Aragonite is not easy to absorb the heat generated by laser due to high transparency, and will not occur thermal oxidation. The addition of fluid can inhibit the thermal oxidation alteration of sulfides, which may be related to the high heat dissipation capacity of water or the adsorption reaction at the fluid-mineral interface, which has enlightenment significance for studying the fluid-mineral interface reaction
(4) Laser Raman spectroscopy has established a series of quantitative analysis models for each component of the fluid, and analyzed the mineral composition and structure. In this study, olivine and water were used as the initial reactants, and the Raman analysis system of fluid-rock interaction established in this paper was applied comprehensively in the laboratory. Serpentine reaction, as a typical water-rock reaction, widely exists in deep-sea ultrabasic hydrothermal system and mud volcano region,which provides an important source of material and energy for deep-sea chemical energy synthesis ecosystem. Initial results of in-situ monitoring the serpentinization reaction show that the Raman peak of olivine became wide at the interface between fluid and rock as the reaction progresses, suggesting that olivine structure damage, this may be due to olivine mineral crystal phonon interaction enhanced. The study provides a clue for further research in the serpentinization process at the interface of the olivine and fluid.
(5) On the basis of comprehensive application in the laboratory simulation system, this paper eventually carried out the in situ detection of fluid and rock interaction in the deep sea based on the Raman analysis methods in lab: the author has taken a large scale in-situ detection of the interaction between fluid and authigenic carbonate for the first time in the active seep Site F, Taixinan Basin, South China Sea. In this study, it was found that with the decrease of biomass density, the crystal structure of aragonite was gradually destroyed and the aragonite content decreased. The results of in situ quantitative analysis of fluids at different sites in Site F indicate that biogeochemical reactions such as methane anaerobic oxidation reaction and methane oxidation reaction occur in the lush biological community, which will form fluids with low salinity and low sulfate. Because of the salt effect, these internal flows can effectively inhibit the erosion of authigenic carbonate rocks, whereas the exposed authigenic carbonate rocks are more susceptible to the erosion and weathering of seawater with high salinity and high sulfate concentration, which provides a new understanding for the study of the evolution of authigenic carbonate rocks. Finally, combining with a large number of in-situ Raman spectra and laboratory XRD and SEM analysis results, the author established the distribution pattern diagram of biocenosis, mineral structure and content, and fluid in Site F, which provides a reference for the study of ecosystem and in situ detection of fluid-rock interaction.

Language中文
Document Type学位论文
Identifierhttp://ir.qdio.ac.cn/handle/337002/170694
Collection海洋地质与环境重点实验室
Recommended Citation
GB/T 7714
席世川. 深海流体-岩石相互作用的拉曼光谱原位分析方法及应用[D]. 中国科学院海洋研究所. 中国科学院大学,2021.
Files in This Item:
File Name/Size DocType Version Access License
深海流体-岩石相互作用的拉曼光谱原位分析(19548KB)学位论文 延迟开放CC BY-NC-SAView 2023-7-31后可获取
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[席世川]'s Articles
Baidu academic
Similar articles in Baidu academic
[席世川]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[席世川]'s Articles
Terms of Use
No data!
Social Bookmark/Share
File name: 深海流体-岩石相互作用的拉曼光谱原位分析方法及应用.pdf
Format: Adobe PDF
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.