Collaborative Research: On how the Bengal-Nicobar fan deposition influenced carbonate cementation in the incoming sediment to the Sumatra subduction zone (IODP Exp 362)

合作研究：孟加拉-尼科巴扇沉积如何影响苏门答腊俯冲带传入沉积物中的碳酸盐胶结作用（IODP Exp 362）

• 批准号: 1833296
• 负责人: Marta Torres
• 金额: $ 15.07万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1833296&HistoricalAwards=false
• 关键词: Collaborative; Research; how; Bengal; Nicobar

The precipitation of carbonate cements, like calcite, changes the physical and mechanical properties of sediments. Depending on the nature of the sediment and its location relative to zones of seismic activity, like subduction zones, carbonate cementation may decrease porosity and permeability and increase sedimentary section rigidity. It can also impact the slip on faults and earthquake rupture processes. Precipitation of carbonate during the alteration of sediments in subduction zones with burial and increasing temperature (i.e., diagenesis) can also provide an important sink for carbon, which may be released from rocks undergoing alteration deeper in the section or by devolatilization and other water-rock interaction processes. Thus, carbonate precipitation in subduction zone sediments can have a significant impact on the carbon cycle. This research examines the formation of carbonate cements in siliciclastic rocks in a major submarine fan deposit within the Sumatra subduction zone. Processes related to the alteration of siliciclastic sediments and their cementation by carbonate will be studied as will processes related to microbially-mediated carbon cycling. Research activities include petrographic investigation of mineral and textural relationships of sediment and cement grains using state-of-the-art imaging technologies. The geochemistry of samples, including stable isotope analyses of carbon, oxygen, and strontium and trace metal compositions of the sediments and their constituent materials will be carried out to try and identify signatures of different processes leading to the formation of carbonate cements. The study will also include work to characterize intergranular pore spaces and grain boundary relations, especially with regard to changes in porosity, permeability, and mineral dissolution features. Project goals include (1) determining the role of carbonate cements in porosity reduction and rock property evolution in subduction zone siliciclastic sediment packages; (2) evaluating the impact of carbonate cement precipitation on the carbon cycle; and (3) determining the thermal and chemical conditions that lead to carbonate cement formation in subduction zone sediments. Broader impacts of the work include student training and incorporation of research into courses. The investigators will work with organizations associated with their home institutions to attract members of groups underrepresented in the sciences and engage them in the research. The investigators will work with students and educators to develop materials to be used in secondary education settings. The project supports two investigators whose genders are underrepresented in the sciences, one of whom serves as a role model for minority students.Whereas we have a solid understanding of carbonate formation driven solely by carbon cycling, either recrystallization of biogenic carbonate or precipitation of methane-derived authigenic carbonate, another mechanism that may significantly influence the formation of sediment cements is where silicate mineral alteration during diagenesis produces bicarbonate and cations that favor precipitation of carbonate minerals. Diagenetic carbonate precipitation efficiently sequesters carbon. Because carbonate in sediments may be released during diagenesis from subducted rocks by devolatization and/or fluid-induced dissolution of calcium carbonate, knowledge of carbonate-carbon inventories in input sediment sequences to subduction zones is important to constrain the inputs to Earth's surface carbon reservoirs. Furthermore, the formation of diagenetic carbonate cements changes the physical and mechanical properties of the hosting sediment, altering its permeability and mechanical strength. The cementation process and the role of silicate weathering on authigenic carbonate formation in marine systems is not well understood. This work documents the relative roles of the coupled carbon-silica system in generating carbonate cements and depositing carbon-bearing minerals in cores of subduction-related siliciclastic sediments. Sediment samples from the Nicobar Fan from the Sumatra subduction zone were selected because they exhibit significant carbonate cementation, having been recently collected on an International Ocean Discovery Program (IODP) drilling expedition to the Indian Ocean. The research focuses on testing the hypothesis that Nicobar Fan carbonate cements formed at depth during burial and diagenesis due to the generation of alkalinity from the alteration of non-carbonate siliciclastic material. Research tasks include (1) comparing the relative roles of carbonate formation through traditional carbon cycling pathways with those via the proposed coupled silicate-carbonate system; (2) identifying chemical reactions in the sediments that lead to carbonate formation; and (3) understating conditions that promote carbonate precipitation from subsurface marine silicate alteration. Sediment samples will be examined petrographically and subjected to X-ray elemental mapping and cathodoluminescence imaging by field-emission scanning electron microscopy. Samples will also be analyzed geochemically. High-resolution carbon, oxygen and strontium isotopes and clumped stable isotope analyses will be carried out in addition to analyses of trace element composition. Data will be used to determine the role of subsurface marine silicates in carbonate cement formation and identify sediment fabric/porosity changes associated with it. Results will contribute to our understanding of the interdependence among fluid-rock reactions, element cycling, and porosity reduction in siliciclastic-dominated systems that experience methanogenesis and will improve our understanding of global carbon budgets, sediment rheology, and faulting in subduction zones.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

碳酸盐水泥的沉淀（如方解石）会改变沉积物的物理和机械性能。根据沉积物的性质及其位置相对于地震活性区域（如俯冲带），碳酸盐胶结物可能会降低孔隙度和渗透率，并增加沉积物部分的刚度。它也会影响断层和地震破裂过程的滑移。 在俯冲带和温度升高（即成岩作用）变化过程中，碳酸盐的沉淀也可以为碳提供重要的水槽，碳可以从该部分中更深入的岩石中释放出来，或者通过更深入的岩石释放，或者通过devolatialition和其他水 - 摇滚相互作用过程。 因此，俯冲带沉积物中的碳酸盐沉淀会对碳循环产生重大影响。 这项研究检查了苏门答腊俯冲带的主要海底风扇矿床中有机碎屑岩石中碳酸盐水泥的形成。将研究与硅质碎屑沉积物的改变及其碳酸盐胶结有关的过程，以及与微生物介导的碳循环有关的过程。 研究活动包括使用最先进的成像技术对沉积物和水泥晶粒的矿物质和质地关系进行岩石学调查。 样品的地球化学，包括碳，氧，氧和锶的稳定同位素分析以及沉积物的痕量金属成分及其成分材料，以尝试识别不同过程的特征，从而导致碳酸盐水泥形成。 该研究还将包括表征晶间孔隙空间和晶界关系的工作，尤其是在孔隙率，渗透率和矿物质溶解特征方面的变化。项目目标包括（1）确定碳酸盐水泥在减少孔隙率和岩石性能进化中的作用，在俯冲带中硅质碎屑沉积物套件中； （2）评估碳酸盐水泥沉淀对碳循环的影响； （3）确定导致俯冲带沉积物中碳酸盐水泥形成的热和化学条件。这项工作的更广泛的影响包括学生培训和将研究纳入课程。 调查人员将与与本国机构相关的组织合作，以吸引科学中人数不足的团体的成员并参与研究。调查人员将与学生和教育者合作开发用于中等教育环境中的材料。 该项目支持两名研究人员，他们的性别在科学中不足，其中一个是少数族裔学生的榜样。Whereas我们对仅由碳循环驱动的碳酸盐形成有着牢固的了解成岩作用产生碳酸氢盐和阳离子，有利于碳酸盐矿物质的降水。成岩碳酸盐沉淀有效地隔离碳。由于沉积物中的碳酸盐在成岩作用期间可以通过脱落岩石和/或流体诱导的碳酸钙溶解在俯冲岩石中释放，因此对俯冲带中碳酸盐碳酸盐库存的知识对于俯冲带中的碳酸盐量库存知识对于将投入到地球表面碳储层中的输入而言很重要。此外，成岩碳酸盐水泥的形成改变了宿主沉积物的物理和机械性能，从而改变了其渗透性和机械强度。尚不清楚胶结过程和硅酸盐风化对海洋系统中碳酸盐形成的作用。这项工作记录了耦合碳 - 二氧化碳系统在产生碳酸盐水泥和沉积碳矿物质矿物质中的相对作用。之所以选择来自苏门答腊俯冲带的尼科巴风扇的沉积物样品，是因为它们表现出明显的碳酸盐胶结化，最近是在国际海洋发现计划（IODP）钻探探险中的。该研究的重点是检验以下假设：尼科巴粉型碳酸盐水泥在埋葬期间在深度和成岩作用过程中形成，这是由于非碳酸盐硅酸盐硅酸盐材料的改变而产生的。研究任务包括（1）通过传统的碳循环途径与通过所提出的硅酸盐碳酸盐系统进行碳酸盐形成的相对作用； （2）鉴定导致碳酸盐形成的沉积物中的化学反应； （3）促进地下海洋硅酸盐改变的碳酸盐沉淀的低调条件。 沉积物样品将在岩石学上检查，并通过现场发射扫描电子显微镜进行X射线元素映射和阴极发光成像。样品也将在地球化学上进行分析。除了对痕量元素组成的分析外，还将进行高分辨率的碳，氧和锶同位素和结块稳定同位素分析。 数据将用于确定地下海洋硅酸盐在碳酸盐水泥形成中的作用，并确定与之相关的沉积物织物/孔隙度变化。结果将有助于我们理解流体岩石反应，元素循环和孔隙率降低硅质主导系统的相互依赖性，这些系统经历了甲烷生成，并将改善我们对全球碳预算，沉积物流变学，沉积物流变性以及俯冲ZONES中的缺陷的理解。这些奖项通过NSF的法定宣传和依据，反映了NSF的法定及其依据，这表明了其法定的依据，并且构成了构成的构成，这是构成的依据。 标准。

项目成果

Silicate weathering in anoxic marine sediment as a requirement for authigenic carbonate burial

• DOI: 10.1016/j.earscirev.2019.102960
• 发表时间: 2020
• 期刊: Earth-Science Reviews
• 影响因子: 12.1
• 作者: M. Torres;W. Hong;E. Solomon;K. Milliken;Ji-hoon Kim;J. Sample;B. Teichert;K. Wallmann

Authigenic Clays Versus Carbonate Formation as Products of Marine Silicate Weathering in the Input Sequence to the Sumatra Subduction Zone

作为苏门答腊俯冲带输入序列中海相硅酸盐风化产物的自生粘土与碳酸盐地层

• DOI: 10.1029/2022gc010338
• 发表时间: 2022
• 期刊: Geosystems
• 作者: Torres, M. E.;Milliken, K. L.;Hüpers, A.;Kim, J. ‐H.;Lee, S. ‐G.
• 通讯作者: Lee, S. ‐G.

Fluid-rock interaction, Nicobar Fan

流体-岩石相互作用，Nicobar Fan

• DOI: 10.18738/t8/amuhst
• 发表时间: 2022
• 期刊: Texas Data Repository
• 作者: Milliken, Kitty;Torres, Marta;Hupers, Andre;Kim, J.-H.;Lee, S.-G.
• 通讯作者: Lee, S.-G.