Qin Mutian, Xing Huilin, Wang Jianchao, Jin Guodong, Hu Zhongwen, Yan Weichao, Tan Yuyang, Liu Junbiao, Zhang Rongxin
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao, 266100, China.
International Center for Submarine Geosciences and Geoengineering Computing (iGeoComp), Ocean University of China, Qingdao, 266100, China.
Sci Rep. 2025 Feb 1;15(1):4000. doi: 10.1038/s41598-025-88077-2.
Dehydration of serpentine is an important prograde metamorphic reaction within the lithosphere and subduction zones, potentially causing profound changes in rock properties. Imaging these transitions in real time provides direct insight into the process. We have used in-situ transmission electron microscopy (TEM) to continuously monitor nanoscale transformations in lizardite from 20 to 600 °C. Phase transformation processes during dehydration are recorded and analyzed in real time, including the amorphization of lizardite, and the recrystallization of nanocrystalline forsterite and talc within amorphous dehydroxylate phases. These observations delimitate the role of dehydration temperature in controlling reaction kinetics and the nucleation of reaction products. Specifically, the higher the temperature, the faster the rate of lizardite dehydration, accompanied by faster and more extensive nucleation of nanocrystalline forsterite and talc. Furthermore, the lizardite crystal is observed to gradually shrink with dehydration while maintaining its structural integrity, leading to the expansion of nanoscale intergranular pores and the formation of interconnected pore networks.
蛇纹石的脱水作用是岩石圈和俯冲带内一种重要的前进变质反应，可能会导致岩石性质发生深刻变化。实时成像这些转变能直接洞察该过程。我们利用原位透射电子显微镜（TEM）在20至600°C的温度范围内连续监测利蛇纹石的纳米级转变。实时记录并分析脱水过程中的相变过程，包括利蛇纹石的非晶化，以及非晶脱羟基相内纳米晶镁橄榄石和滑石的再结晶。这些观察结果界定了脱水温度在控制反应动力学和反应产物成核方面的作用。具体而言，温度越高，利蛇纹石脱水速率越快，同时纳米晶镁橄榄石和滑石的成核速度越快且范围更广。此外，观察到利蛇纹石晶体在脱水过程中逐渐收缩，同时保持其结构完整性，导致纳米级晶间孔隙扩张并形成相互连通的孔隙网络。
