Geochronology, petrogenesis, and tectonic implications of the Early Permian volcanic rocks in the northern margin of the North China Craton

Abstract

We present new zircon U–Pb ages, geochemical data on the Late Palaeozoic volcanic rocks of the Suji and Dahongshan formations, which are exposed in the Plate Marginal Orogenic Belt along the northern margin of the North China Craton. Our aim is to constrain the petrogenesis, tectonic setting of volcanic rocks, and to address the late stage tectonic evolution of the Paleo‐Asian Ocean. Lithologically, the Suji and Dahongshan formations present the main rock association with basaltic andesite, andesite, dacite, rhyolite, and tuff. New zircon U–Pb dating results suggest that the volcanic rocks formed during 280–261 Ma and 277–267 Ma, respectively. Geochemically, these volcanic rocks belong to the low‐K tholeiitic to high‐K calc‐alkaline series and are characterized by highly enriched light rare earth elements, K, Rb, Ba; depleted Nb, Ta, Ti; and highly negative Eu anomalies, very similar to that of the continental arc magmatism. These data, together with geological field investigations, suggest that the Early Permian volcanic rocks from Suji and Dahongshan formations were related to southward flat subduction of the Paleo‐Asian Ocean beneath the northern margin of the North China Craton. Therefore, these volcanic rocks were interpreted as Andean‐style continental margin arc magmatism. This also indicates that the final collision between the North China Craton and the Siberian Craton did not occur until the Early Permian.

Geochronology and geochemistry of the Late Devonian–Early Carboniferous volcanic rocks in Aksu River area, western end of the East Kunlun Orogen

“…The rhyolite samples plot in the field of volcanic arc in the (Y + Ta)‐Rb and (Y + Nb)‐Rb diagrams. Hence, we propose that the tectonic setting of the volcanic rocks is related to the subduction process (R. B. Li, Pei, et al, ; J. L. Li, Zhou, et al, ; Murphy, ; Rogers & Hawkesworth, ).…”

“…The EKO is bounded by the Qaidam basin to the north, the Bayan Har‐Songpan Ganze terrane to the south, the Altyn Tagh strike‐slip fault to the west, and the Wenquan Fault to the east (Figure b; X. H. Chen, Gehrels, Yin, Li, & Jiang, ; Xiong et al, ; X. H. Chen et al, ; X. W. Li, Huang, Luo, Dong, & Mo, ; R. Xia, ). The EKO can be divided into North Kunlun‐Qaidam terrane (NK‐QT) and South Kunlun terrane (SKT) by Central Kunlun Fault (CKLF; Figure b; X. H. Chen et al, ; X. H. Chen et al, ; X. W. Li et al, ; R. B. Li, Pei, et al, ; J. L. Li, Zhou, et al, ; Meng, Zhang, & Cui, ; Xiong, ; Xu et al, ; Xu et al, ).…”

“…The NKT is characterized by the Precambrian Jinshuikou Group metamorphic basement and widespread of the Early Palaeozoic and Mesozoic plutons with two age peaks of 420–400 and 260–220 Ma (Figure c; Z. Q. Liu, ). The Jinshuikou Group consists of marble, gneiss and amphibolite, and experienced amphibolite‐granulite‐facies metamorphism, which is covered by the Binggou Group with an unconformity contact (R. B. Li, Pei, et al, ; J. L. Li, Zhou, et al, ; Meng et al, ; R. Xia et al, ;Xiong, ; Xiong, Ma, Jiang, et al, ; Xiong, Ma, Zhang, et al, ). The Binggou Group comprises volcano‐sedimentary and low‐grade metamorphic rocks (Xiong, ).…”

“…W. Li et al, 2015;R. B. Li, Pei, et al, 2018;J. L. Li, Zhou, et al, 2018;Meng, Zhang, & Cui, 2013;Xiong, 2014;Xu et al, 2007;Xu et al, 2013).…”

“…The Jinshuikou Group consists of marble, gneiss and amphibolite, and experienced amphibolite-granulite-facies metamorphism, which is covered by the Binggou Group with an unconformity contact (R. B. Li, Pei, et al, 2018;J. L. Li, Zhou, et al, 2018;Meng et al, 2013;Xiong, 2014 ;Xiong, Ma, Zhang, et al, 2014).…”