Abstract

The Uyandina–Yasachnaya volcanoplutonic belt (UYVB) is located in Northeast Asia. As one of the largest volcanic belts in the region, it extends for 900 km from the headwaters of the Kolyma River in the northwesterly direction. The Late Jurassic UYVB overlaps the folds of the Cherskii collision belt. The UYVB rocks are characterized by highly variable facies indicating the heterogeneous nature of the belt. The UYVB has been studied at the cross section of the Indigirka River. This paper reports the first data on U–Pb dating of zircons and the geochemical features of rocks. The concordant U–Pb age of volcanic rocks is 150 ± 2–152 ± 2 Ma (Kimmeridgian–Volgian of the Late Jurassic). It is concluded that the formation conditions of the volcanic rocks change upward through the section, from those typical of mature island arcs to those more typical of active continental margins.

中文翻译：

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Uyandina-Yasachnaya火山带（东北亚，Indigirka段）火山岩的U–Th–Pb（SIMS）年代和形成条件

摘要

Uyandina–Yasachnaya火山成岩带（UYVB）位于东北亚。作为该地区最大的火山带之一，它从科利马河的源头向西北延伸了900公里。侏罗纪晚期的UYVB与Cherskii碰撞带的褶皱重叠。UYVB岩石的特征是高度变化的相，表明该带是非均质的。UYVB已在英迪吉尔卡河（Indigirka River）的横断面进行了研究。本文报道了锆石的U–Pb测年数据和岩石的地球化学特征。火山岩的一致U–Pb年龄为150±2–152±2 Ma（侏罗纪晚期的Kimmeridgian–Volgian）。结论是，火山岩的形成条件通过该段向上变化，