Kai Lan , Xiting Liu , Anchun Li , Fangjian Xu , Peijun Qiao , Houjie Wang
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This was caused by shelf exposure during low sea-level periods when the sediments were fully exposed and the residence time in the weathering zone was long, leading the shelf sediments to undergo consistent and complete weathering under supply-limited conditions. In comparison, during cold events on the millennium-centennial time scale, such as Younger Dryas, 8.2 ka, and 4.2 ka, chemical weathering was weaker (lower CIA values) due to accelerated erosion as a result of lower temperatures and higher precipitation, which shortened the rocks’ residence in the weathering zone, resulting in the control of chemical weathering shifted from supply factors to kinetic ones, such as temperature and precipitation. Our findings suggest that on the orbital time scale, glacial shelf exposure could enhance chemical weathering, thereby reducing atmospheric CO<sub>2</sub>; on the millennium-centennial time scale, chemical weathering could rapidly respond to abrupt climate events.</p></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Changes in chemical weathering regime of shelf sediments of the East China Sea controlled by sea-level and climatic changes since the last deglaciation\",\"authors\":\"Kai Lan , Xiting Liu , Anchun Li , Fangjian Xu , Peijun Qiao , Houjie Wang\",\"doi\":\"10.1016/j.jseaes.2024.106169\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Chemical weathering of shelf sediments is important in driving the global elemental cycle and climate to maintain the earth’s habitability. However, the response mechanism between chemical weathering of shelf sediments and climate and sea-level changes is still unclear. This study focuses on core ECMZ located in the mud area of the East China Sea (ECS) inner shelf. The results indicate that the mechanisms controlling chemical weathering in the sediment of the ECS inner shelf differ at different timescales. On the orbital time scale, the Chemical Index of Alteration (CIA) indicates that the intensity of chemical weathering in sediments during the deglacial period was significantly higher than that during the Holocene. This was caused by shelf exposure during low sea-level periods when the sediments were fully exposed and the residence time in the weathering zone was long, leading the shelf sediments to undergo consistent and complete weathering under supply-limited conditions. In comparison, during cold events on the millennium-centennial time scale, such as Younger Dryas, 8.2 ka, and 4.2 ka, chemical weathering was weaker (lower CIA values) due to accelerated erosion as a result of lower temperatures and higher precipitation, which shortened the rocks’ residence in the weathering zone, resulting in the control of chemical weathering shifted from supply factors to kinetic ones, such as temperature and precipitation. Our findings suggest that on the orbital time scale, glacial shelf exposure could enhance chemical weathering, thereby reducing atmospheric CO<sub>2</sub>; on the millennium-centennial time scale, chemical weathering could rapidly respond to abrupt climate events.</p></div>\",\"PeriodicalId\":50253,\"journal\":{\"name\":\"Journal of Asian Earth Sciences\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2024-05-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Asian Earth Sciences\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1367912024001640\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Asian Earth Sciences","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1367912024001640","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
陆架沉积物的化学风化作用在推动全球元素循环和气候以维持地球宜居性方面具有重要作用。然而,陆架沉积物化学风化与气候和海平面变化之间的响应机制尚不清楚。本研究以位于东海内陆架泥质区的核心 ECMZ 为研究对象。研究结果表明,控制东海内陆架沉积物化学风化的机制在不同时间尺度上存在差异。在轨道时间尺度上,化学蚀变指数(CIA)表明,冰期沉积物的化学风化强度明显高于全新世。这是由于在低海平面时期大陆架完全暴露,沉积物在风化带的停留时间较长,导致大陆架沉积物在供给有限的条件下持续、完全地风化。相比之下,在千年-百年时间尺度上的寒冷事件期间,如杨格干期、8.2 ka 和 4.2 ka,由于温度较低和降水较多导致侵蚀加速,缩短了岩石在风化带的停留时间,化学风化作用较弱(CIA 值较低),导致化学风化作用的控制因素从供应因素转向温度和降水等动力学因素。我们的研究结果表明,在轨道时间尺度上,冰川陆架的暴露可以加强化学风化,从而减少大气中的二氧化碳;在千年-百年时间尺度上,化学风化可以对突变的气候事件迅速做出反应。
Changes in chemical weathering regime of shelf sediments of the East China Sea controlled by sea-level and climatic changes since the last deglaciation
Chemical weathering of shelf sediments is important in driving the global elemental cycle and climate to maintain the earth’s habitability. However, the response mechanism between chemical weathering of shelf sediments and climate and sea-level changes is still unclear. This study focuses on core ECMZ located in the mud area of the East China Sea (ECS) inner shelf. The results indicate that the mechanisms controlling chemical weathering in the sediment of the ECS inner shelf differ at different timescales. On the orbital time scale, the Chemical Index of Alteration (CIA) indicates that the intensity of chemical weathering in sediments during the deglacial period was significantly higher than that during the Holocene. This was caused by shelf exposure during low sea-level periods when the sediments were fully exposed and the residence time in the weathering zone was long, leading the shelf sediments to undergo consistent and complete weathering under supply-limited conditions. In comparison, during cold events on the millennium-centennial time scale, such as Younger Dryas, 8.2 ka, and 4.2 ka, chemical weathering was weaker (lower CIA values) due to accelerated erosion as a result of lower temperatures and higher precipitation, which shortened the rocks’ residence in the weathering zone, resulting in the control of chemical weathering shifted from supply factors to kinetic ones, such as temperature and precipitation. Our findings suggest that on the orbital time scale, glacial shelf exposure could enhance chemical weathering, thereby reducing atmospheric CO2; on the millennium-centennial time scale, chemical weathering could rapidly respond to abrupt climate events.
期刊介绍:
Journal of Asian Earth Sciences has an open access mirror journal Journal of Asian Earth Sciences: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review.
The Journal of Asian Earth Sciences is an international interdisciplinary journal devoted to all aspects of research related to the solid Earth Sciences of Asia. The Journal publishes high quality, peer-reviewed scientific papers on the regional geology, tectonics, geochemistry and geophysics of Asia. It will be devoted primarily to research papers but short communications relating to new developments of broad interest, reviews and book reviews will also be included. Papers must have international appeal and should present work of more than local significance.
The scope includes deep processes of the Asian continent and its adjacent oceans; seismology and earthquakes; orogeny, magmatism, metamorphism and volcanism; growth, deformation and destruction of the Asian crust; crust-mantle interaction; evolution of life (early life, biostratigraphy, biogeography and mass-extinction); fluids, fluxes and reservoirs of mineral and energy resources; surface processes (weathering, erosion, transport and deposition of sediments) and resulting geomorphology; and the response of the Earth to global climate change as viewed within the Asian continent and surrounding oceans.