Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean
The origin and tectonic implication of Early–Middle Devonian magmatism in the northern margin of YB (Yili Block) remain enigmatic and are important for understanding Late Paleozoic evolution of the Junggar Ocean and southern Kazakhstan Orocline. Here, we present the systematic study of whole-rock ge...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/11/11/1248 |
| _version_ | 1797509263709437952 |
|---|---|
| author | Youxin Chen Shengqiang Zhu Xianzhi Pei Lei He Jun Zhao Bate Bulong Meng Wang Shaowei Zhao Hai Zhou |
| author_facet | Youxin Chen Shengqiang Zhu Xianzhi Pei Lei He Jun Zhao Bate Bulong Meng Wang Shaowei Zhao Hai Zhou |
| author_sort | Youxin Chen |
| collection | DOAJ |
| description | The origin and tectonic implication of Early–Middle Devonian magmatism in the northern margin of YB (Yili Block) remain enigmatic and are important for understanding Late Paleozoic evolution of the Junggar Ocean and southern Kazakhstan Orocline. Here, we present the systematic study of whole-rock geochemical and Sr–Nd isotope features as well as U–Pb–Hf isotope characteristics of zircon crystals for newly identified Early Devonian volcanic rocks from the northern margin of YB. The volcanic rocks are composed of rhyolite, rhyolite porphyry, and rhyolitic tuff. Zircon U-Pb age dating indicates they were formed at ca. 407~418 Ma. They have high SiO<sub>2</sub> (70.16–77.52 wt.%) and alkali (5.10–9.56 wt.%) contents, and high Zr + Nb + Ce + Y content (~456 ppm), indicative of A-type magma. Their relative depletion of Nb, Ta, and Ti, and enrichment of LILEs show arc affinity. Their low initial <sup>87</sup>Sr/<sup>86</sup>Sr ratios (0.699708–0.709822) and negative <i>ε</i><sub>Nd</sub>(t) values (−1.8 to −4.0) indicate a mainly continental magma source and their positive <i>ε</i><sub>Hf</sub>(t)values (+6.13 to +14.81) are possibly due to the garnet effect. All these above reveal that volcanic rocks were generated by re-melting of lower crust under a high temperature condition, which was induced by long-lived heat accumulation with no or minimal basalt flux. Combined with active continental margin inference evidenced by contemporaneous sedimentary rocks, we attribute the generation of the volcanic rocks to a continental arc setting related to the southward subduction of Junggar oceanic crust. Thus, we infer the Early–Middle Devonian arc-related magmatic rocks in the northern margin of YB are eastward counterparts of the southern limb of the Devonian Volcanic Belt, which resulted from a relatively steady-state southward subduction. |
| first_indexed | 2024-03-10T05:15:14Z |
| format | Article |
| id | doaj.art-e244a74f5ef44cef83372891c8f6478f |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T05:15:14Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-e244a74f5ef44cef83372891c8f6478f2023-11-23T00:32:30ZengMDPI AGMinerals2075-163X2021-11-011111124810.3390/min11111248Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar OceanYouxin Chen0Shengqiang Zhu1Xianzhi Pei2Lei He3Jun Zhao4Bate Bulong5Meng Wang6Shaowei Zhao7Hai Zhou8School of Earth Science and Resources, Chang’an University, Xi’an 710054, ChinaSchool of Earth Science and Resources, Chang’an University, Xi’an 710054, ChinaSchool of Earth Science and Resources, Chang’an University, Xi’an 710054, ChinaThe Fifth Oil Production Plant, Changqing Oilfield Company, PetroChina, Xi′an 710200, ChinaDepartment of Science and Technology, Northwest University of Political Science and Law, Xi’an 710054, ChinaCenter of Urumqi Natural Resources Comprehensive Survey, China Geological Survey, Urumqi 830057, ChinaSchool of Earth Science and Resources, Chang’an University, Xi’an 710054, ChinaSchool of Earth Science and Resources, Chang’an University, Xi’an 710054, ChinaSchool of Earth Science and Resources, Chang’an University, Xi’an 710054, ChinaThe origin and tectonic implication of Early–Middle Devonian magmatism in the northern margin of YB (Yili Block) remain enigmatic and are important for understanding Late Paleozoic evolution of the Junggar Ocean and southern Kazakhstan Orocline. Here, we present the systematic study of whole-rock geochemical and Sr–Nd isotope features as well as U–Pb–Hf isotope characteristics of zircon crystals for newly identified Early Devonian volcanic rocks from the northern margin of YB. The volcanic rocks are composed of rhyolite, rhyolite porphyry, and rhyolitic tuff. Zircon U-Pb age dating indicates they were formed at ca. 407~418 Ma. They have high SiO<sub>2</sub> (70.16–77.52 wt.%) and alkali (5.10–9.56 wt.%) contents, and high Zr + Nb + Ce + Y content (~456 ppm), indicative of A-type magma. Their relative depletion of Nb, Ta, and Ti, and enrichment of LILEs show arc affinity. Their low initial <sup>87</sup>Sr/<sup>86</sup>Sr ratios (0.699708–0.709822) and negative <i>ε</i><sub>Nd</sub>(t) values (−1.8 to −4.0) indicate a mainly continental magma source and their positive <i>ε</i><sub>Hf</sub>(t)values (+6.13 to +14.81) are possibly due to the garnet effect. All these above reveal that volcanic rocks were generated by re-melting of lower crust under a high temperature condition, which was induced by long-lived heat accumulation with no or minimal basalt flux. Combined with active continental margin inference evidenced by contemporaneous sedimentary rocks, we attribute the generation of the volcanic rocks to a continental arc setting related to the southward subduction of Junggar oceanic crust. Thus, we infer the Early–Middle Devonian arc-related magmatic rocks in the northern margin of YB are eastward counterparts of the southern limb of the Devonian Volcanic Belt, which resulted from a relatively steady-state southward subduction.https://www.mdpi.com/2075-163X/11/11/1248Central Asian Orogenic Beltnorthern margin of Yili Blockthe Early Devonianvolcanic rockssubduction |
| spellingShingle | Youxin Chen Shengqiang Zhu Xianzhi Pei Lei He Jun Zhao Bate Bulong Meng Wang Shaowei Zhao Hai Zhou Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean Minerals Central Asian Orogenic Belt northern margin of Yili Block the Early Devonian volcanic rocks subduction |
| title | Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean |
| title_full | Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean |
| title_fullStr | Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean |
| title_full_unstemmed | Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean |
| title_short | Early Devonian Arc-Related Volcanic Rocks in the Haerdaban, North Margin of the Yili Block: Constraint on the Southward Subduction of the Junggar Ocean |
| title_sort | early devonian arc related volcanic rocks in the haerdaban north margin of the yili block constraint on the southward subduction of the junggar ocean |
| topic | Central Asian Orogenic Belt northern margin of Yili Block the Early Devonian volcanic rocks subduction |
| url | https://www.mdpi.com/2075-163X/11/11/1248 |
| work_keys_str_mv | AT youxinchen earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT shengqiangzhu earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT xianzhipei earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT leihe earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT junzhao earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT batebulong earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT mengwang earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT shaoweizhao earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean AT haizhou earlydevonianarcrelatedvolcanicrocksinthehaerdabannorthmarginoftheyiliblockconstraintonthesouthwardsubductionofthejunggarocean |