1. Early Cretaceous arc-related volcanic rocks in the northern Great Xing’an Range, NE China: records of Paleo-Pacific ocean subduction
- Author
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Hai‐Na Li, Zhi‐Gang Yin, and Jun Han
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Rhyodacite ,Subduction ,Andesite ,Geochemistry ,010502 geochemistry & geophysics ,Dacite ,01 natural sciences ,Volcanic rock ,Rhyolite ,General Earth and Planetary Sciences ,Mafic ,Geology ,0105 earth and related environmental sciences ,Zircon - Abstract
There are widespread Late Mesozoic volcanic rocks in the Great Xing’an Range, Northeast China. However, the precise age data and tectonic evolution are still controversial. In this paper, a suite of intermediate-felsic volcanic rocks and mafic volcanic rocks have been recognized in the Daheishan of the northern Great Xing’an Range. Zircon U–Pb dating constrains two groups of the crystallization ages at 129 Ma (dacite) and 124–127 Ma (rhyolite, rhyodacite and andesite), respectively. They all have magmatic zircon geochemical characteristics, including systematic positive Ce anomalies, weak negative Eu anomalies, and high Th/U ratios (average 0.84). The intermediate-felsic volcanic rocks show crustal signatures with high K2O (1.91–7.57 wt% and low MgO (0.19–2.78 wt%) contents. The zircon eHf(t) values mostly range from + 4.7 to + 10.2, with dominant two-stage model ages (TDM2) of 530–878 Ma. Therefore, combined with previous data, the mantle-derived mafic melts may have triggered partial melting of the juvenile lower crust to produce intermediate-felsic magmas, and the source rock is considered to be an amphibolite. In addition, the trace element data of the volcanic rocks display arc-like signatures. The published and our geochronological data indicate that these Late Mesozoic volcanic rocks in the Great Xing’an Range were mainly formed in the Early Cretaceous with a peak range of 124–133 Ma. The large-scale Early Cretaceous volcanic rocks in the Great Xing’an Range were formed in an active continental margin setting related to the subduction of the Paleo-Pacific Ocean.
- Published
- 2021
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