Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt
As the southernmost segment of the Central Asian Orogenic Belt (CAOB), the northern Alxa orogenic belt (NAOB) connects the southeastern and southwestern segments of the CAOB. The NAOB amalgamated with the closure of the Paleo-Asian Ocean; however, the closure time of the Paleo-Asian Ocean is still o...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2020-07-01
|
| Series: | Geoscience Frontiers |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674987119302403 |
| _version_ | 1797762331176861696 |
|---|---|
| author | Yan Chen Tairan Wu Zhicheng Zhang C. Mark Fanning Mingming Zhang |
| author_facet | Yan Chen Tairan Wu Zhicheng Zhang C. Mark Fanning Mingming Zhang |
| author_sort | Yan Chen |
| collection | DOAJ |
| description | As the southernmost segment of the Central Asian Orogenic Belt (CAOB), the northern Alxa orogenic belt (NAOB) connects the southeastern and southwestern segments of the CAOB. The NAOB amalgamated with the closure of the Paleo-Asian Ocean; however, the closure time of the Paleo-Asian Ocean is still on great debate. In this study, we reported new detrital zircon U–Pb geochronology and Hf–O isotopes for the Permo–Carboniferous sediments in the northern Alxa to constrain the provenance and its tectonic implications. The Permo–Carbonifereous Amushan Formation is composed of volcanic-carbonite-clastic rocks and was deposited in a shallow marine environment. Based on the zircon U–Pb geochronology, the Amushan Formation was deposited in the late Carboniferous to early Permian, but some outcrops of volcanic and clastic rocks in the Quaganqulu area were likely formed in the middle to late Permian. The integrated zircon age spectrum for the clastic rocks shows a wide range from late Archean to Paleoproterozoic, Mesoproterozoic (with a peak age at 1458 Ma), early Neoproterozoic (with peak ages of 988 Ma and 929 Ma), early Paleozoic (with a peak age at 447 Ma) and late Paleozoic (with a peak age at 294 Ma). Combined with the zircon Hf–O isotopes, the provenance was considered to be the Alxa Block, the Shalazhashan terrane and the Zhusileng–Hangwula block (and the southern Beishan orogenic belt). The multiple source regions to the south and north of the Paleo-Asian Ocean indicate the closure of this ocean before the late Carboniferous. The absence or small proportion of depositional age-approximated zircons in most samples makes their age spectra similar to extensional basins. Combined with the intra-plate volcanism, the deposits were considered to be formed in extensional settings. Accordingly, after the closure of the Paleo-Asian Ocean, the NAOB stepped into an extensional stage. |
| first_indexed | 2024-03-12T19:26:49Z |
| format | Article |
| id | doaj.art-8d66a7d666ce4b4387a919dae94136db |
| institution | Directory Open Access Journal |
| issn | 1674-9871 |
| language | English |
| last_indexed | 2024-03-12T19:26:49Z |
| publishDate | 2020-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geoscience Frontiers |
| spelling | doaj.art-8d66a7d666ce4b4387a919dae94136db2023-08-02T04:51:01ZengElsevierGeoscience Frontiers1674-98712020-07-0111414151429Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic BeltYan Chen0Tairan Wu1Zhicheng Zhang2C. Mark Fanning3Mingming Zhang4Institute for Peat and Mire Research, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun 130024, China; Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China; Corresponding author. School of Geographical Sciences, Northeast Normal University, No. 5268 Remin Street, Nanguan District, Changchun 130024, China.The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, ChinaThe Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, ChinaResearch School of Earth Sciences, Australian National University, Mills Road, Canberra, ACT, 0200, AustraliaInstitute for Peat and Mire Research, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun 130024, China; Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, ChinaAs the southernmost segment of the Central Asian Orogenic Belt (CAOB), the northern Alxa orogenic belt (NAOB) connects the southeastern and southwestern segments of the CAOB. The NAOB amalgamated with the closure of the Paleo-Asian Ocean; however, the closure time of the Paleo-Asian Ocean is still on great debate. In this study, we reported new detrital zircon U–Pb geochronology and Hf–O isotopes for the Permo–Carboniferous sediments in the northern Alxa to constrain the provenance and its tectonic implications. The Permo–Carbonifereous Amushan Formation is composed of volcanic-carbonite-clastic rocks and was deposited in a shallow marine environment. Based on the zircon U–Pb geochronology, the Amushan Formation was deposited in the late Carboniferous to early Permian, but some outcrops of volcanic and clastic rocks in the Quaganqulu area were likely formed in the middle to late Permian. The integrated zircon age spectrum for the clastic rocks shows a wide range from late Archean to Paleoproterozoic, Mesoproterozoic (with a peak age at 1458 Ma), early Neoproterozoic (with peak ages of 988 Ma and 929 Ma), early Paleozoic (with a peak age at 447 Ma) and late Paleozoic (with a peak age at 294 Ma). Combined with the zircon Hf–O isotopes, the provenance was considered to be the Alxa Block, the Shalazhashan terrane and the Zhusileng–Hangwula block (and the southern Beishan orogenic belt). The multiple source regions to the south and north of the Paleo-Asian Ocean indicate the closure of this ocean before the late Carboniferous. The absence or small proportion of depositional age-approximated zircons in most samples makes their age spectra similar to extensional basins. Combined with the intra-plate volcanism, the deposits were considered to be formed in extensional settings. Accordingly, after the closure of the Paleo-Asian Ocean, the NAOB stepped into an extensional stage.http://www.sciencedirect.com/science/article/pii/S1674987119302403CAOBAlxaProvenancePermo–CarboniferousDetrital zircon |
| spellingShingle | Yan Chen Tairan Wu Zhicheng Zhang C. Mark Fanning Mingming Zhang Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt Geoscience Frontiers CAOB Alxa Provenance Permo–Carboniferous Detrital zircon |
| title | Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt |
| title_full | Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt |
| title_fullStr | Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt |
| title_full_unstemmed | Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt |
| title_short | Provenance of the Permo–Carboniferous sediments in the northern Alxa and its tectonic implications for the southernmost Central Asian Orogenic Belt |
| title_sort | provenance of the permo carboniferous sediments in the northern alxa and its tectonic implications for the southernmost central asian orogenic belt |
| topic | CAOB Alxa Provenance Permo–Carboniferous Detrital zircon |
| url | http://www.sciencedirect.com/science/article/pii/S1674987119302403 |
| work_keys_str_mv | AT yanchen provenanceofthepermocarboniferoussedimentsinthenorthernalxaanditstectonicimplicationsforthesouthernmostcentralasianorogenicbelt AT tairanwu provenanceofthepermocarboniferoussedimentsinthenorthernalxaanditstectonicimplicationsforthesouthernmostcentralasianorogenicbelt AT zhichengzhang provenanceofthepermocarboniferoussedimentsinthenorthernalxaanditstectonicimplicationsforthesouthernmostcentralasianorogenicbelt AT cmarkfanning provenanceofthepermocarboniferoussedimentsinthenorthernalxaanditstectonicimplicationsforthesouthernmostcentralasianorogenicbelt AT mingmingzhang provenanceofthepermocarboniferoussedimentsinthenorthernalxaanditstectonicimplicationsforthesouthernmostcentralasianorogenicbelt |