Mafic–intermediate igneous rocks in the East Kunlun Orogenic Belt, northwestern China: Petrogenesis and implications for regional geodynamic evolution during the Triassic

Xin, Wei; Sun, Fengyue; Zhang, Yuting; Fan, Xingzhu; Wang, Yingchao; Li, Liang

doi:10.1016/j.lithos.2019.105159

Cited by 35 publications

(57 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Baishiya granodiorite porphyries have negligible Eu anomalies and relatively flat HREE features (Figure 6a), indicating that the adakitic rocks were generated from a magmatic source with residual amphibole but a relatively small amount of plagioclase (Ou et al, 2017). The T DM2 model ages of Nd isotope are in the range of 1,426–1,554 Ma and consistent with the T DM2 of Hf–Nd isotopes of the regional Triassic granites which have been proved to derive from an ancient Mesoproterozoic mafic lower crust of the EKOB (Xin et al, 2019; Xiong et al, 2014), indicating that Baishiya granodiorite porphyries occurred from deep melting or remelting of the Mesoproterozoic crustal material. The initial 87 Sr/ 88 Sr values (0.7091–0.7093) of Baishiya granodiorite porphyries are less than the typical UCC values (>0.72) and are close to LCC values (0.702–0.705; Rollinson, 1993); their ε Nd (t) values (−6.84 to −5.27) are higher than those of UCC and LCC (Figure 7).…”

Section: Discussionsupporting

confidence: 77%

“…The Eastern Kunlun Orogenic Belt (EKOB)—a northern part of the Tethys metallogenic belt—contains typical Triassic magmatism and associated mineralization recorded in China (Mao, 2012; Wang et al, 2016). Many studies indicate that the Triassic magmatism in the EKOB reveals the nature of crust–mantle interaction and traces the geodynamic setting for synchronous mineralization (Deng, Wang, Li, & Santosh, 2014; Feng et al, 2004; Jia, Mao, Li, Zhang, & Sun, 2020; Jia, Meng, & Feng, 2018; Li et al, 2010; Tian, 2012; Xin et al, 2019; Xiong et al, 2019; Xiong, Ma, Zhang, Liu, & Jiang, 2014; Xu, 2014; Yu et al, 2017). The EKOB experienced the opening and closing of the A'nyemaqen Ocean—the north branch of the Palaeo‐Tethys Ocean—during the Triassic period (Jiang et al, 1992; Mo et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…The EKOB experienced the opening and closing of the A'nyemaqen Ocean—the north branch of the Palaeo‐Tethys Ocean—during the Triassic period (Jiang et al, 1992; Mo et al, 2007). Researchers studying Permian–Triassic magmatism in the EKOB hold different opinions on the timing of closing of the A'nyemaqen Ocean and the subsequent continental collision: (a) the closing of the A'nyemaqen Ocean began in the Late Permian and was followed by the collisional orogeny stage of the tectonic system and the formation of post‐collisional Triassic granites(Huang et al, 2014; Luo, Ke, Cao, Deng, & Chen, 2002; Mo et al, 2007; Yuan, Wang, & Wang, 2000); (b) the A'nyemaqen Ocean initiated collision‐orogeny in the Middle Triassic (Chen et al, 2013; Guo & Deng, 1998; Kong, Niu, Hu, Zhang, & Shao, 2020; Shao et al, 2017; Xiong, 2014; Xu et al, 2013); (c) the A'nyemaqen Ocean experienced subduction until the Late Triassic (Chen et al, 2017; Wang et al, 2011; Yuan et al, 2009; Zhao et al, 2020); (d) the EKOB experienced collision‐orogeny from the Late–Middle to Early–Late Triassic, post‐collision in the Late Triassic, and intracontinental orogeny in the Middle–Late Jurassic (Xin et al, 2019). Thus, although multiple studies address Permian‐Triassic magmatism in the EKOB, the timing of closing of the A'nyemaqen Ocean and the subsequent continental collision remain controversial.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Petrogenesis and tectonic significance of Late Triassic Baishiya granodiorite porphyries in the Dulan area, eastern segment of the East Kunlun Orogenic Belt, China

Liang

Xia

et al. 2020

Geological Journal

View full text Add to dashboard Cite

The timing of closing of the A'nyemaqen Ocean—the north branch of the Palaeo‐Tethys Ocean—and the subsequent continental collision remain controversial. In this study, detailed geochronological and geochemical analyses of the Baishiya granodiorite porphyries in the Dulan area [eastern segment of the East Kunlun Orogen Belt (EKOB)] were conducted. The LA–ICP–MS zircon U–Pb dating analysis revealed that the Baishiya granodiorite porphyries were emplaced during the Late Triassic (~223 Ma) and possess adakitic features, including relatively high SiO2 (67.2–69.0 wt%), Al2O3 (15.2–15.9 wt%), and Sr (416–540 ppm) contents, low Y (10.5–12.3 ppm) and Yb (1.03–1.38 ppm) contents, and high Sr/Y and La/Yb ratios. They belong to the high‐K calc‐alkaline series and show significant light rare‐earth element enrichment, minor Eu anomalies, HFSE depletion, and LILE enrichment. The porphyries record a narrow range of (87Sr/86Sr)i ratios (0.709067–0.709920) and ɛNd(t) values (−6.84 to −5.27) with two‐stage model ages (TDM2) ranging from 1,426 to 1,554 Ma. These geochemical features imply that the Baishiya granodiorite porphyries originated from the partial melting of the thickened Mesoproterozoic lower crust by mixing with minor mantle‐derived material. Late Triassic adakitic magmatism in the eastern segment of the EKOB formed in a post‐collisional extension setting due to the closing of the A'nyemaqen Ocean since Early Triassic.

show abstract

Section: Discussionsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Petrogenesis and tectonic significance of Late Triassic Baishiya granodiorite porphyries in the Dulan area, eastern segment of the East Kunlun Orogenic Belt, China

Liang

Xia

et al. 2020

Geological Journal

View full text Add to dashboard Cite

show abstract

“…Therefore, during 254-240 Ma, which widespread mafic dike swarms occurred (Xiong et al, 2011(Xiong et al, , 2013, indicates an extensional tectonic regime, which resulted in significant calc-alkaline magmatism. During 240-230 Ma, calc-alkaline and intermediate-acidic occurrence without adakitic characteristics (Xiong et al, 2014;Shao et al, 2017;Xin et al, 2019) probably indicate a slab break-off and upwelling of the asthenosphere. The eastern part of EKO represents a transitional (syn-collisional) magmatic peak between subduction and post-collision.…”

Section: Timing and Geodynamic Settingmentioning

confidence: 99%

Genesis of HarizhaAg–Pb–Zndeposit in the eastern Kunlun Orogen,NWChina: Evidence of fluid inclusions andC–H–O–S–Pbisotopes

Fan

Sun

et al. 2021

Resource Geology

Self Cite

View full text Add to dashboard Cite

The Harizha Ag-Pb-Zn deposit is located in the eastern part of the eastern Kunlun Orogen, NW China. Two episodes including five paragenetic stages of vein mineralization has been recognized for the Harizha Ag-Pb-Zn deposit through petrographic observation: quartz + pyrite + arsenopyrite (Stage I), quartz + pyrite + chalcopyrite + pyrrhotite (Stage II), quartz + pyrite + chalcocite + pyrrhotite + sphalerite + galena + pyrargyrite (Stage III), quartz + calcite + pyrite + tetrahedrite + pyrolusite (Stage IV), and calcite + covellite + malachite + goethite + graphite (Stage V). In the quartz or calcite three types of fluid inclusions (FIs) were identified: L-type, C-type, and Stype. The S-type inclusions are only found in quartz in the wall rocks. The Ctype inclusions occur in quartz from early episodes (Stage I and II). The FIs from the early episodes homogenized at 240-320 C, with salinities of 9-12 wt. % NaCl equivalent. The ore-forming fluids at the early episodes belong to an H 2 O-CO 2 -CH 4 -NaCl system. The FIs from late episodes (Stage III and IV) homogenized at 140-240 C, with salinities of 2-8 wt% NaCl equivalent. The ore-forming fluids from the late episodes are dominated by an H 2 O-NaCl fluid system. The H O and C O isotopic compositions of quartz and calcite indicate that the ore-forming fluids were derived from a primary magmatichydrothermal system, with subsequent meteoric water involvement at a later stage. Sulfides have δ 34 S values of −3.7 to -1.0‰, and 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios ranging from 18.381 to 18.425, 15.661 to 15.683, and 38.498 to 38.677, respectively. These likely suggest a magmatic sulfur affinity combined with the ore features, mineral associations, alteration characteristics, ore-forming environment, and fluid evolutionary process. We conclude that the Harizha Ag-Pb-Zn deposit is a typical medium-low temperature hydrothermal deposit.

show abstract

“…In addition, granitoids in the EKOB record the growth and evolution of continental crust, with precise dating of these intrusions providing insights into different stages of evolution of the EKOB. A multitude of studies have focused on the evolution of the Palaeo-Tethys Ocean and associated massifs/terrains in the EKOB region (Chen et al, 2017;Ding, Jiang, & Sun, 2014;Ding, Liu, & Yan, 2015;Shao et al, 2017;Xia et al, 2015;Xin et al, 2019;Xiong et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Middle to Late Triassic granitic magmatism in the East Kunlun Orogenic Belt, NW China: Petrogenesis and implications for a transition from subduction to post‐collision setting of the Palaeo‐Tethys Ocean

Gao

Sun

2021

Geological Journal

View full text Add to dashboard Cite

In this study, we present new geochronological and petrogenetic data for the Triassic granitoids of the East Kunlun Orogenic Belt (EKOB), in order to constrain their precise ages, petrogenesis, and tectonic settings. LA-ICP-MS zircon U-Pb data indicate that the Triassic granitoids were emplaced in two stages: (a) Middle Triassic (247-240 Ma), represented by a suite of porphyritic granites and granodiorites; and (b) Late Triassic (234-227 Ma), forming an intrusive rock association of K-feldspar granites, granodiorites, and porphyritic granites. Geochemical analyses and mineral associations suggest that all the Triassic granitoids belong to I-type granites but have different origins. The Middle Triassic granitoids have high SiO 2 , low to moderate Mg # values (25-37 for XSG porphyritic granite; 45-47 for DB granodiorite), low Sr/Y ratios (2.2-4.6 for XSG porphyritic granite; 17.8-20.8 for DB granodiorite), and rela-tively restricted zircon εHf(t) values (+2.4 − +4.6 for the ca. 247 Ma porphyritic granite, and − 8.0 to −1.5 for the ca. 240 Ma granodiorite), indicating that they were dominantly generated from partial melting of different crust sources (either juvenile or ancient) in a normal lower crust level. In contrast, the Late Triassic granitoids have high SiO 2 , K 2 O, and Y contents, low MgO and HREE contents, and variable zircon εHf(t) values (from negative to positive, −4.9 to +3.3), implying a strong crustal-mantle interaction that occurred during the Late Triassic, and this stage of granitoids were derived from a complex magma source possibly a mixture of mantle-derived and ancient crustal-derived materials. By combining these new data with the previous data, we conclude that the two stages of Triassic granitoids were emplaced in an active continental margin setting and a post-collisional extension setting, respectively. Moreover, this study suggests a tectonic shift of the Palaeo-Tethys Ocean in the EKOB from subduction during the Middle Triassic to a post-collision during the Late Triassic.

show abstract

Mafic–intermediate igneous rocks in the East Kunlun Orogenic Belt, northwestern China: Petrogenesis and implications for regional geodynamic evolution during the Triassic

Cited by 35 publications

References 65 publications

Petrogenesis and tectonic significance of Late Triassic Baishiya granodiorite porphyries in the Dulan area, eastern segment of the East Kunlun Orogenic Belt, China

Petrogenesis and tectonic significance of Late Triassic Baishiya granodiorite porphyries in the Dulan area, eastern segment of the East Kunlun Orogenic Belt, China

Genesis of HarizhaAg–Pb–Zndeposit in the eastern Kunlun Orogen,NWChina: Evidence of fluid inclusions andC–H–O–S–Pbisotopes

Middle to Late Triassic granitic magmatism in the East Kunlun Orogenic Belt, NW China: Petrogenesis and implications for a transition from subduction to post‐collision setting of the Palaeo‐Tethys Ocean

Contact Info

Product

Resources

About