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首页> 外文期刊>Journal of geodynamics >Basement segmentation and tectonic structure of the Lomonosov Ridge, arctic Ocean: Insights from bedrock geochronology
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Basement segmentation and tectonic structure of the Lomonosov Ridge, arctic Ocean: Insights from bedrock geochronology

机译：北冰洋罗蒙诺索夫海岭的基底分割和构造结构：基岩年代学的见解

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Apparent variations in the morphology of the Lomonosov Ridge and its along-strike segmentation are caused by the heterogeneity of the basement. Based on the morphological diversity, we divide the Lomonosov Ridge into three segments: Siberian, Central and North American. New petrographic and geochronological data from the rock clasts sampled in the "Arctika-2007-1" expedition, are integrated with seismic and relevant mineralogical, petrographic and isotopic data. Recovered fragments of the high-grade metamorphic and siliciclastic rocks are attributed to the bedrock of the Siberian and Central Segments of the Lomonosov Ridge respectively.The mineralogical and isotopic analysis of detrital zircons from Neoproterozoic arkose defines the Grenvillian age for the basement of the Siberian Segment of the Lomonosov Ridge. The U-Pb dating of the metamorphic zircons from gneisses and schists suggests that Timanian crystalline basement of the Central Segment was affected by an upper-Ordivician (similar to 450 Ma) felsic magmatism, followed by the mid- to high-grade Caledonian tectonometamorphic event (similar to 400 Ma). The Central Segment is therefore inferred to be a frontal part of Caledonian convergent shear and fold zone.Caledonian deformation front is suggested between the northeastern and southwestern islands of De Long archipelago. Northward from the shelf break, the orogenic front is expected between the Geophysicists Spur and the main horst of the Siberian Segment. Within the Central Segment the Caledonian deformation front is inferred to stretch along the western flank of the Lomonosov Ridge.
机译：罗蒙诺索夫海岭的形态和沿走向的分段的明显变化是由于基底的异质性引起的。根据形态多样性，我们将罗蒙诺索夫海岭分为三个部分：西伯利亚，中美洲和北美。来自“ Arctika-2007-1”探险队采样的岩石碎屑的新岩石学和年代学数据与地震和相关的矿物学，岩石学和同位素数据结合在一起。高品位的变质和硅质碎屑岩的碎屑分别归因于罗蒙诺索夫岭的西伯利亚和中段的基岩，新元古代阿科斯的碎屑锆石的矿物学和同位素分析确定了西伯利亚段基底的格林维尔时代。罗蒙诺索夫海岭。片麻岩和片岩变质锆石的U-Pb年代测定表明，中段的Timanian结晶基底受上奥陶纪（约450 Ma）的长岩浆作用的影响，其次是中高级喀里多尼亚地壳构造事件。 （类似于400 Ma）。因此，将中段推定为喀里多尼亚辐合剪切和褶皱带的前缘部分。建议在德隆群岛的东北和西南岛屿之间建立卡利多尼亚形变锋。从陆架折断点向北，预计造山带锋线位于地球物理学家马刺和西伯利亚地段的主要地壳之间。在中央部分内，推断加里东变形前沿沿着罗蒙诺索夫海岭的西翼伸展。

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