气候变化领域集成服务门户(CCPortal): Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard

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DOI	10.1016/j.epsl.2020.116319
	Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard
	Jang K.; Bayon G.; Han Y.; Joo Y.J.; Kim J.-H.; Ryu J.-S.; Woo J.; Forwick M.; Szczuciński W.; Kim J.-H.; Nam S.-I.
发表日期	2020
ISSN	0012821X
卷号	542
英文摘要	Neodymium (Nd) isotopes in leached authigenic components of marine sediments have been increasingly used as a tracer of past ocean-water masses. Despite the general assumption that the Nd isotopic composition of solutes released during chemical weathering fingerprints the source rocks on continents, preferential dissolution of easily dissolvable phases may result in significant deviations in Nd isotopic composition between the solutes and the source rocks, with potential implications for the utility of Nd isotopes in paleoenvironmental studies. Here, we present the Nd isotopic compositions of leached and detrital fractions separated from bedrock and marine sediment samples from the Svalbard archipelago. Our goal is to further understand the behaviour of Nd isotopes during chemical weathering in glacial catchments and evaluate how glacier fluctuations and associated weathering congruency may have affected the export of dissolved Nd isotope signatures to seawater. Our results confirm that terrestrial weathering on Svalbard causes considerable Nd isotopic decoupling between the leached and detrital fractions of fjord sediments (△εNd), resulting from the preferential dissolution of marine precipitates in glaciated catchments dominated by sedimentary rocks. We also show that the degree of Nd isotopic decoupling has fluctuated in response to climate variability on Svalbard during the Holocene, which is also as suggested by the occurrence of generally higher △εNd values during periods of glacier advances in sediment cores retrieved from two different fjords (Dicksonfjorden and Woodfjorden). We posit that the high △εNd values can be ascribed to incongruent chemical weathering of fresh rock flour produced by glacial abrasion. This finding suggests that the degree of Nd isotopic decoupling could be used as a new proxy for tracing glacial fluctuations and associated glacier-derived nutrient inputs to the marine realm. © 2020 Elsevier B.V.
关键词	glacier fluctuation incongruent weathering isotopic decoupling neodymium isotopes Svalbard
英文关键词	Catchments; Dissolution; Erosion; Geochemistry; Glacial geology; Isotopes; Leaching; Neodymium; Runoff; Sedimentary rocks; Sediments; Submarine geology; Chemical weathering; Climate variability; Detrital fractions; Glacier fluctuations; Nd isotopic compositions; Neodymium isotopes; Paleoenvironmental study; Preferential dissolution; Weathering; chemical weathering; glacial environment; isotopic composition; neodymium isotope; paleoenvironment; source rock; Arctic; Svalbard; Svalbard and Jan Mayen
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202674
作者单位	Division of Polar Paleoenvironment, Korea Polar Research Institute, Incheon, 21990, South Korea; IFREMER, Marine Geosciences Unit, Plouzané, F-29280, France; Petroleum and Marine Resources Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, South Korea; Department of Earth and Environmental Sciences, Pukyong National University, Busan, 48513, South Korea; School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, South Korea; UiT The Arctic University of Norway, Department of Geosciences, Tromsø, NO-9037, Norway; Geohazards Lab, Institute of Geology, Adam Mickiewicz University in Poznań, Poznań, 61-680, Poland
推荐引用方式 GB/T 7714	Jang K.,Bayon G.,Han Y.,et al. Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard[J],2020,542.
APA	Jang K..,Bayon G..,Han Y..,Joo Y.J..,Kim J.-H..,...&Nam S.-I..(2020).Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard.Earth and Planetary Science Letters,542.
MLA	Jang K.,et al."Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard".Earth and Planetary Science Letters 542(2020).