{"title":"北冰洋中部罗蒙诺索夫海岭MIS 4-3沉积记录的黏土矿物及Nd、Pb、Sr同位素物源","authors":"Raisa Alatarvas, Ninna Immonen, K. Strand","doi":"10.17741/bgsf/95.1.003","DOIUrl":null,"url":null,"abstract":"Modern techniques for detrital mineral provenance were applied to sediment core 96/12-1pc from the Lomonosov Ridge in the central Arctic Ocean. The techniques include quantitative clay mineralogy analysis combined with determination of Nd, Pb, and Sr isotopes from clay fraction. The clay mineral assemblage and the isotope signatures depict distinct changes during the Marine Isotope Stage (MIS) 4-3 transition corresponding to the Middle Weichselian deglaciation. This transition is characterised by a homogenous, 48 cm thick, dark grey, silty clay layer with a distinctive IRD concentration, forming a prominent marker bed for the central Arctic Ocean sediments. The elevated smectite and kaolinite contents in the transitional interval are possible weathering products of the Siberian basaltic rocks, such as the Putorana Plateau, feeding the shelves of the Kara Sea and the western Laptev Sea. The Nd and Sr isotope values are compatible with input from the basaltic rocks and fall within the isotopic range of sediments from these shelves. The abrupt changes in the Nd, Pb and Sr isotopic data from the distinct grey layer attributed to the MIS 4-3 transition likely mark a pronounced deglaciation event. An increase in coarse debris in the grey layer indicates a change in the sedimentation regime with a strong iceberg rafting component. This change may also be related to a sudden release of meltwater from a large ice-dammed lake in the northern Siberia.","PeriodicalId":55302,"journal":{"name":"Bulletin of the Geological Society of Finland","volume":null,"pages":null},"PeriodicalIF":1.3000,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Clay mineral and Nd, Pb, and Sr isotope provenance of a MIS 4-3 sediment record from the Lomonosov Ridge, central Arctic Ocean\",\"authors\":\"Raisa Alatarvas, Ninna Immonen, K. Strand\",\"doi\":\"10.17741/bgsf/95.1.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Modern techniques for detrital mineral provenance were applied to sediment core 96/12-1pc from the Lomonosov Ridge in the central Arctic Ocean. The techniques include quantitative clay mineralogy analysis combined with determination of Nd, Pb, and Sr isotopes from clay fraction. The clay mineral assemblage and the isotope signatures depict distinct changes during the Marine Isotope Stage (MIS) 4-3 transition corresponding to the Middle Weichselian deglaciation. This transition is characterised by a homogenous, 48 cm thick, dark grey, silty clay layer with a distinctive IRD concentration, forming a prominent marker bed for the central Arctic Ocean sediments. The elevated smectite and kaolinite contents in the transitional interval are possible weathering products of the Siberian basaltic rocks, such as the Putorana Plateau, feeding the shelves of the Kara Sea and the western Laptev Sea. The Nd and Sr isotope values are compatible with input from the basaltic rocks and fall within the isotopic range of sediments from these shelves. The abrupt changes in the Nd, Pb and Sr isotopic data from the distinct grey layer attributed to the MIS 4-3 transition likely mark a pronounced deglaciation event. An increase in coarse debris in the grey layer indicates a change in the sedimentation regime with a strong iceberg rafting component. This change may also be related to a sudden release of meltwater from a large ice-dammed lake in the northern Siberia.\",\"PeriodicalId\":55302,\"journal\":{\"name\":\"Bulletin of the Geological Society of Finland\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2023-06-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Bulletin of the Geological Society of Finland\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.17741/bgsf/95.1.003\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the Geological Society of Finland","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.17741/bgsf/95.1.003","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOLOGY","Score":null,"Total":0}
Clay mineral and Nd, Pb, and Sr isotope provenance of a MIS 4-3 sediment record from the Lomonosov Ridge, central Arctic Ocean
Modern techniques for detrital mineral provenance were applied to sediment core 96/12-1pc from the Lomonosov Ridge in the central Arctic Ocean. The techniques include quantitative clay mineralogy analysis combined with determination of Nd, Pb, and Sr isotopes from clay fraction. The clay mineral assemblage and the isotope signatures depict distinct changes during the Marine Isotope Stage (MIS) 4-3 transition corresponding to the Middle Weichselian deglaciation. This transition is characterised by a homogenous, 48 cm thick, dark grey, silty clay layer with a distinctive IRD concentration, forming a prominent marker bed for the central Arctic Ocean sediments. The elevated smectite and kaolinite contents in the transitional interval are possible weathering products of the Siberian basaltic rocks, such as the Putorana Plateau, feeding the shelves of the Kara Sea and the western Laptev Sea. The Nd and Sr isotope values are compatible with input from the basaltic rocks and fall within the isotopic range of sediments from these shelves. The abrupt changes in the Nd, Pb and Sr isotopic data from the distinct grey layer attributed to the MIS 4-3 transition likely mark a pronounced deglaciation event. An increase in coarse debris in the grey layer indicates a change in the sedimentation regime with a strong iceberg rafting component. This change may also be related to a sudden release of meltwater from a large ice-dammed lake in the northern Siberia.
期刊介绍:
Bulletin of the Geological Society of Finland (BGSF) publishes research articles and short communications in all branches of geosciences. Contributions from outside Finland are welcome, provided that they contain material relevant to Finnish geology or are of general interest.