LISTVEIN: Multiscale structure evolution during peridotite carbonation and hydration in an oceanic subduction zone: a case study of listvenite in the Oman Ophiolite

LISTVEIN：大洋俯冲带橄榄岩碳化和水化过程中的多尺度结构演化：阿曼蛇绿岩中的 Listvenite 案例研究

• 批准号: 420525991
• 负责人: Professor Dr. Klaus Reicherter, since 9/2019
• 金额: --
• 依托单位: Lehr- und Forschungsgebiet Geologie - Endogene Dynamik (GED) (aufgelöst)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/420525991?language=en
• 关键词: LISTVEIN; Multiscale; structure; evolution; during

Listvenites in the Oman Ophiolite formed from oceanic mantle peridotite thrust over carbonate-bearing sediments in the hanging wall of a subduction zone. In this example of large scale peridotite hydration and carbonation processes, core BT1 of the ICDP Oman Drilling Project (OmDP) provides a unique sample. Although listvenites record carbon fluxes in oceanic subduction zones and are a possible natural analogue for carbon capture and storage via mineralization, the processes by which this carbonation occurs are not well understood, calling for work to understand the evolution of this natural example. We propose a micro- and macrostructural study of deformation and reaction structures in listvenite and serpentinized peridotite in Core BT1. Using optical and electron microscopy (ViP, CL, BIB-SEM, EDX, EBSD, QEMSCAN) integrated with our core description data and with the state of the art image data (core scans, X-ray CT, hyperspectral, XRF) collected by OmDP, we will focus on (i) the different generations of fault, cataclasite and fracture and vein structures modifying the listvenite microstructure, analyzing overprinting relationships and deformation mechanisms, (ii) the microstructure of listvenite, testing the presence of a ductile shear zone during carbonation, (iii) the microstructure of protolith serpentinites and partially altered peridotites, (iv) microstructures in syntaxial and antitaxial veins to distinguish reaction-induced- from tectonically and pore pressure-induced fracturing, and finally (v) on micro- and nano-porosity and its connectivity to constrain potential fluid pathways in the matrix.We aim to better understand the interplay of force of crystallization, tectonic stress and pore pressure during large scale hydration and carbonation processes in BT1 and test hypotheses on driving forces, structural evolution and fluid transport pathways in this system. More generally, we hope to contribute a process-oriented perspective to studies of mass transfer and element “recycling” in subduction zones, and to understand the effect of mass transfer and mineralogical transformation on plate-boundary deformation.

由海洋金矿石形成的阿曼蛇绿岩中的绿岩石在碳酸盐岩悬挂壁上的碳酸盐沉积物上，大规模橄榄石水合和碳酸化过程，ICDP Oman钻探项目（OMDP）的核心BT1。尽管海洋俯冲带中的列表是一种自然的样本，但通过矿化是一种自然的捕获，但通过低语碳化的过程却没有很好地理解，我们提出了叉子来理解自然的示例。与我们的核心描述数据和图像数据的状态（核心扫描状态）集成在一起（VIP，CL，EDX，EBSD，EBSD，QEMSCAN）中的Listvenite和蛇形橄榄石中的蛇状橄榄石。 X射线CT，高光谱，XRF）由OMDP集体，我们将重点介绍（i）（i）（i）修饰Listvenite微孔的丙片岩和果实和静脉结构，分析了过度打印的关系和变形机制，ListGenite的微观结构，测试了尘埃剪切的存在碳中的区域。为了更好地解释BT1中的结晶力，量表水合和碳酸过程中的孔隙压力，并在驱动力上测试假设，结构性进化和流体RT途径。 - 针对俯冲带的巨毛和元素“回收蛋白”的研究的视角，并了解suster虫和矿物学转化对板 - 结合变形的影响。