{"title":"艾尔吉特金湖(楚科奇半岛阿纳德尔高原)沉积物中的奥杜威事件地球化学特征","authors":"P. Minyuk","doi":"10.2113/rgg20244732","DOIUrl":null,"url":null,"abstract":"\n —The paper is concerned with study of the distribution of geochemical characteristics in the sediments of Lake El’gygytgyn (Chukchi Peninsula) formed during the Olduvai event. A clear geochemical and rock-magnetic zoning of the section has been established, which reflects global climatic changes. The geochemical zones coincide with marine isotope stages MIS 75–MIS 61. The sediments of warm stages are characterized by elevated contents of mobile components (SiO2, CaO, Na2O, K2O, and Sr), high values of magnetic susceptibility, low contents of Fe2O3, MgO, TiO2, Al2O3, Rb, Zr, and Ni, and low values of LOI, paramagnetic component, and chemical indices of alteration. The reverse pattern is observed for the sediments of cold stages. The low values of magnetic susceptibility in the sediments of optimal stages MIS 63, MIS 65, MIS 71, and MIS 75 are due to the dilution of detrital material with a biogenic one. The upper boundary of the Olduvai event passes in warm stage MIS 63, and the lower boundary coincides with the boundary between MIS 74 and MIS 75. The products of weathering of the Cretaceous felsic rocks of the Pykarvaam and Ergyvaam formations located near Lake El’gygytgyn were the provenances for its sediments. According to the geochemical and rock-magnetic data, the sedimentation during the Olduvai event was a cyclic process with periods of ca. 54, 40–43, and 23 kyr. The orbital cycles of 40–43 and 23 kyr indicate global causes of geochemical changes.","PeriodicalId":49587,"journal":{"name":"Russian Geology and Geophysics","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Geochemical Features of the Olduvai Event in the Sediments of Lake El’gygytgyn (Anadyr Plateau, Chukchi Peninsula)\",\"authors\":\"P. Minyuk\",\"doi\":\"10.2113/rgg20244732\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n —The paper is concerned with study of the distribution of geochemical characteristics in the sediments of Lake El’gygytgyn (Chukchi Peninsula) formed during the Olduvai event. A clear geochemical and rock-magnetic zoning of the section has been established, which reflects global climatic changes. The geochemical zones coincide with marine isotope stages MIS 75–MIS 61. The sediments of warm stages are characterized by elevated contents of mobile components (SiO2, CaO, Na2O, K2O, and Sr), high values of magnetic susceptibility, low contents of Fe2O3, MgO, TiO2, Al2O3, Rb, Zr, and Ni, and low values of LOI, paramagnetic component, and chemical indices of alteration. The reverse pattern is observed for the sediments of cold stages. The low values of magnetic susceptibility in the sediments of optimal stages MIS 63, MIS 65, MIS 71, and MIS 75 are due to the dilution of detrital material with a biogenic one. The upper boundary of the Olduvai event passes in warm stage MIS 63, and the lower boundary coincides with the boundary between MIS 74 and MIS 75. The products of weathering of the Cretaceous felsic rocks of the Pykarvaam and Ergyvaam formations located near Lake El’gygytgyn were the provenances for its sediments. According to the geochemical and rock-magnetic data, the sedimentation during the Olduvai event was a cyclic process with periods of ca. 54, 40–43, and 23 kyr. The orbital cycles of 40–43 and 23 kyr indicate global causes of geochemical changes.\",\"PeriodicalId\":49587,\"journal\":{\"name\":\"Russian Geology and Geophysics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2024-07-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Russian Geology and Geophysics\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.2113/rgg20244732\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Geology and Geophysics","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.2113/rgg20244732","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
-本文主要研究奥杜维事件期间形成的艾尔吉特金湖(楚科奇半岛)沉积物的地球化学特征分布。该区段的地球化学和岩石磁性分区清晰,反映了全球气候的变化。地球化学分区与 MIS 75-MIS 61 海洋同位素阶段相吻合。暖期沉积物的特点是移动成分(SiO2、CaO、Na2O、K2O 和 Sr)含量高,磁感应强度值高,Fe2O3、MgO、TiO2、Al2O3、Rb、Zr 和 Ni 含量低,LOI、顺磁性成分和蚀变化学指数值低。冷阶段沉积物的情况则相反。最佳阶段 MIS 63、MIS 65、MIS 71 和 MIS 75 沉积物中的低磁感应强度值是由于碎屑物质被生物物质稀释所致。奥杜威事件的上边界位于 MIS 63 暖期,下边界与 MIS 74 和 MIS 75 的边界相吻合。埃尔吉特金湖附近的白垩纪长英岩Pykarvaam和Ergyvaam地层的风化产物是其沉积物的来源。根据地球化学和岩石磁性数据,奥杜威事件期间的沉积是一个循环过程,周期分别为约 54、40-43 和 23 千年。40-43 千年和 23 千年的轨道周期表明地球化学变化是全球性的。
Geochemical Features of the Olduvai Event in the Sediments of Lake El’gygytgyn (Anadyr Plateau, Chukchi Peninsula)
—The paper is concerned with study of the distribution of geochemical characteristics in the sediments of Lake El’gygytgyn (Chukchi Peninsula) formed during the Olduvai event. A clear geochemical and rock-magnetic zoning of the section has been established, which reflects global climatic changes. The geochemical zones coincide with marine isotope stages MIS 75–MIS 61. The sediments of warm stages are characterized by elevated contents of mobile components (SiO2, CaO, Na2O, K2O, and Sr), high values of magnetic susceptibility, low contents of Fe2O3, MgO, TiO2, Al2O3, Rb, Zr, and Ni, and low values of LOI, paramagnetic component, and chemical indices of alteration. The reverse pattern is observed for the sediments of cold stages. The low values of magnetic susceptibility in the sediments of optimal stages MIS 63, MIS 65, MIS 71, and MIS 75 are due to the dilution of detrital material with a biogenic one. The upper boundary of the Olduvai event passes in warm stage MIS 63, and the lower boundary coincides with the boundary between MIS 74 and MIS 75. The products of weathering of the Cretaceous felsic rocks of the Pykarvaam and Ergyvaam formations located near Lake El’gygytgyn were the provenances for its sediments. According to the geochemical and rock-magnetic data, the sedimentation during the Olduvai event was a cyclic process with periods of ca. 54, 40–43, and 23 kyr. The orbital cycles of 40–43 and 23 kyr indicate global causes of geochemical changes.
期刊介绍:
The journal publishes original reports of theoretical and methodological nature in the fields of geology, geophysics, and geochemistry, which contain data on composition and structure of the Earth''s crust and mantle, describes processes of formation and general regularities of commercial mineral occurrences, investigations on development and application of geological-geophysical methods for their revealing. As to works of regional nature, accelerated publication are available for original papers on a variety of problems of comparative geology taking into account specific character of Siberia, adjacent Asian countries and water areas. The journal will also publish reviews, critical articles, chronicle of the most important scientific events, and advertisements.