Geochronology and Geochemistry of Igneous Rocks from the Laoshankou District, North Xinjiang: Implications for the Late Paleozoic Tectonic Evolution and Metallogenesis of East Junggar

The tectonic evolution of the Irtysh tectonic belt: New zircon U–Pb ages of arc-related and collisional granitoids in the Kalaxiangar tectonic belt, NW China

“…360 Ma) of a molybdenite vein parallel to the foliation of the Yuleken Cu deposit (Xiang et al, 2012). These ages are further in agreement with the Kalaxiangar 354 Ma dioritic porphyrite (Lü et al, 2012), the 355Ma Tuerkubantao granitic gneiss and the 367-362 Ma formation age of the Gorny Altay granite (Kruk et al, 2011).…”

Pyrite and magnetite Re–Os isotope systematics at the Laoshankou Fe–Cu–Au deposit in the northern margin of the East Junggar terrane, NW Xinjiang, China: Constraints on the multistage mineralization and metal sources

“…Moreover, the ages of sulfide‐Cu‐Au mineralization are in broad agreement with the zircon LA‐ICP‐MS U‐Pb ages of the mineralization‐related monzodiorite (379.2 ± 4.4 Ma; Liang, Chen, Wu, & Liu, ), diorite porphyry (379.7 ± 3.0 Ma; Lu, Yang, et al, ), quartz syenite (376.3 ± 2.3 Ma; Liang, Chen, Hollings, Wu, et al, ), and biotite diorite (380.5 ± 2.2 Ma; Liang et al, ) in Laoshankou, which indicated that the sulfide‐Cu‐Au mineralization has a temporal relationship with related magmatism (Figure ). Combined with the metallogenic and magmatic ages in Halasu (381–372 Ma; Wu et al, ; Xue et al, ; Yang et al, ; Wu et al, ), Yuelekehalasu (379–374 Ma; F. Yang et al, ; F. Yang, Chai, Zhang, Geng, & Li, ), and Qiaoxiahala (380–375 Ma; Zhang et al, ; Li et al, ; Liang et al, 2016), these ages indicate that the tectonic evolution of ~380 Ma may not only form voluminous magmatism, but also generate related porphyry copper and sulfide‐Cu‐Au mineralization in the northern margin of the East Junggar.…”

“…Hence, the Fe–Cu–Au mineralization in the Laoshankou deposit are two‐stage mineralization, that is, Fe and sulfide‐Cu‐Au. Combined with the above geochronology of igneous rocks and deposit geological characteristics, the Fe–Cu–Au mineralization are closely related to the early Late Paleozoic magmatic‐metallogenic event (390–370 Ma; Wu et al, ; Xue et al, ; Lu, Zhang, et al, ) in the northern margin of the East Junggar, possibly triggered by the southward subduction of Paleo‐Asian Ocean lithosphere beneath the Junggar continent as indicated by other studies (Liang, Chen, Hollings, Wu, et al, ; Liang, Chen, Hollings, Xiao, et al, ; Long et al, ; Xu et al, ; Xu et al, ).…”

“…Southward subduction of the Erqis‐Kuerti oceanic crust (a southern branch of the Paleo‐Asian Ocean) and northward subduction of the Junggar oceanic crust beneath the East Junggar Terrane from the Devonian to Permian generated the predominant Late Paleozoic volcano‐sedimentary and intrusive units in the northern margin of the East Junggar terrane (Figure C; J. Xu et al, ; Long et al, ; X. Xu et al, ). The Late Paleozoic felsic magmatic intrusions in the region mainly emplaced in two epochs of 390–370 Ma and 320–270 Ma (Li & Chen, ; Tong, ; G. Wu, Dong, & Xue, ; Xue et al, ; S. Lu et al, ), with evolution from mostly I‐type calc‐alkaline igneous activity to A‐type alkaline granite, which consisted with the evolution from a basin inversion in a volcanic arc setting (Liang et al, ) to a postcollision/intraplate extension setting (Han, Ji, Song, Chen, & Zhang, ; Liang et al, ; Liang et al, ). All Paleozoic strata strike northwest and dip northeast (Z. Zhang et al, ), which are parallel to the regional structures.…”

“…The intrusive rocks in the deposit are mainly monzodiorite, diorite porphyry, biotite diorite, quartz syenites, and diorite dykes. They mainly occurred along the NW‐SE striking F5, the N‐striking F6 faults and intruded the Beitashan Formation (Figure A) at 379.2 ± 4.4 Ma, 379.7 ± 3.0 Ma, 379.3 ± 2.3 Ma, 376.3 ± 2.3 (or 366.3 ± 1.9 Ma), and 353.8 ± 1.9 Ma, respectively (zircon U‐Pb; Liang, Chen, Hollings, Wu, et al, ; Liang, Chen, Wu, & Liu, ; Lu, Yang, et al, ).…”