Abstract

The paper presents seismogeodynamic analysis of modern structures located in the Lena river delta. These structures are key elements in the tectonic evolution of the shelf–continent transition zone in the Arctic segment of the boundary between the Eurasian and North American lithospheric plates. The geological structure of the Lena river delta is predetermined by the junction of the ancient Siberian platform and the Mesozoic Laptev Sea plate. These two large geoblocks of the crust, which differ in age, are separated by a fragment of the Kharaulakh segment of the Verkhoyansk fold system. In our study aimed to reveal regularities in seismotectonic destruction of the crust, we analyzed the geological and geophysical data on the crustal structure, active faults, modern structural plan, dynamic characteristics of the modern relief, and hydrological features characterizing of the flow redistribution in the Lena riverbed. A system of active faults identified in the Lena river delta shows a contrasting kinematic plan of the junction zone of the main geostructures. According to the analysis results, shear faulting is a dominant factor of impact on the morphologic features and seismogeodynamic activation of the modern structures. A regional right-lateral strike-slip fault of the sublatitudinal strike is traced as a major structural boundary that cuts the Lena river delta into several geodynamic segments. Seismotectonic destruction of the crust in the segments differs in types (transpression, transtension and compression). The above-mentioned fault is not only the main element of the kinematic plan of the newest structures in the Lena river delta – it controls the general structural pattern and seismotectonic parameters of active fault zones in the entire northern sector of the Verkhoyansk marginal suture. The seismogeodynamic analysis results obtained in our study provide a reliable basis for estimating potential seismic hazard of the modern structures in the Lena river delta and updating the available seismic zoning maps of the shelf–continent transition zone in the Arctic segment of the boundary between the Eurasian and North American lithospheric plates.

中文翻译：

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勒纳河三角洲现代构造的浮雕和地震构造动力学

摘要

本文介绍了位于利纳河三角洲的现代结构的地震地球动力学分析。这些结构是欧亚大陆板块与北美岩石圈板块边界的北极段陆架-大陆过渡带构造演化的关键要素。利纳河三角洲的地质结构是由古老的西伯利亚平台和中生代拉普捷夫海板交界处预先确定的。年龄不同的这两个地壳大地块被韦尔霍扬斯克褶皱系统的Kharaulakh段的一部分隔开。在我们旨在揭示地壳地震构造破坏规律的研究中，我们分析了地壳结构，活动断层，现代构造计划，现代浮雕的动态特征等地质和地球物理数据，和水文特征表征了Lena河床的流量重新分布。在Lena河三角洲发现的活动断层系统显示出主要地质结构交界区的运动学对比图。根据分析结果，剪切断裂是影响现代结构形态特征和地震动力作用的主要因素。纵裂走向的区域右旋走滑断层被追踪为一个主要的结构边界，该边界将莉娜河三角洲切分为几个地球动力学段。区段中地壳的地震构造破坏的类型不同（超压，超压和压缩）。上述断层不仅是勒纳河三角洲最新结构运动学计划的主要内容，而且还控制了Verkhoyansk边缘缝合线整个北段活动断层带的总体构造模式和地震构造参数。我们的研究获得的地震动力分析结果为估算Lena河三角洲现代结构的潜在地震危险以及更新欧亚大陆之间边界的北极大陆架-大陆过渡带的可用地震分区图提供了可靠的基础。和北美岩石圈板块。