Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology
The formation of the East Kunlun Orogen (EKO) was related to the tectonic evolution of the Proto-Tethys and Paleo-Tethys Oceans. However, how the Paleo-Tethys Ocean transited from the Proto-Tethys Ocean, and whether the Paleo-Tethys Ocean subducted northward beneath the East Kunlun–Qaidam Terrane in...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-02-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/13/3/312 |
| _version_ | 1797609981654073344 |
|---|---|
| author | Xiao Wang Xianzhi Pei Ruibao Li Chengjun Liu Lei Pei Zuochen Li Youxin Chen Meng Wang |
| author_facet | Xiao Wang Xianzhi Pei Ruibao Li Chengjun Liu Lei Pei Zuochen Li Youxin Chen Meng Wang |
| author_sort | Xiao Wang |
| collection | DOAJ |
| description | The formation of the East Kunlun Orogen (EKO) was related to the tectonic evolution of the Proto-Tethys and Paleo-Tethys Oceans. However, how the Paleo-Tethys Ocean transited from the Proto-Tethys Ocean, and whether the Paleo-Tethys Ocean subducted northward beneath the East Kunlun–Qaidam Terrane in Carboniferous to Permian times, is still highly debated. Early Carboniferous Halaguole and Late Carboniferous to Early Permian Haoteluowa formations are extensively outcropped in the EKO, north Tibetan Plateau, and have thus recorded key information about the tectonic processes of the Paleo-Tethys Ocean that have implications for the reconstruction of the Northern Paleo-Tethys Ocean (Buqingshan Ocean). Siliciclastic rocks within these formations are collected for petrogeological, geochemical, and detrital zircon U–Pb dating research. Our results show that sandstones from Halaguole and Haoteluowa formations have an average total quartz–feldspar–lithic fragment ratio of Q<sub>67</sub>F<sub>12</sub>L<sub>21</sub> and Q<sub>50</sub>F<sub>20</sub>L<sub>30</sub>, respectively, indicating relatively high compositional maturity. The geochemical results suggest that the average values of the Chemical Index of Alteration (CIA) are 57.83 and 64.66; together with their angular to subangular morphology, this indicates that their source rocks suffered from weak weathering and the sandstones are the result of proximal deposition. Geochemical features such as the low La/Th, TiO<sub>2</sub>, and Ni values suggest that the parental rocks in the provenance area are mainly acidic igneous rocks with minor intermediate igneous and old sedimentary components. The detrital zircon U–Pb age spectrum of these samples is dominated by age peaks at ~405–503 Ma and ~781–999 Ma, with subordinate age peaks at ~1610–2997 Ma and ~1002–1529 Ma, which show tectono–thermal events similar to those of the North Qimatag Belt (NQB), North Kunlun Terrane (NKT), and South Kunlun Terrane (SKT). These features suggest a contribution from the Early Paleozoic magmatic arc and Proterozoic basements in the NQB, NKT, and SKT to the Halaguole and Haoteluowa formations in these areas. In addition, the youngest zircon age of ~440 Ma from these sandstones is greater than the depositional age of Halaguole and Haoteluowa formations, which is a typical basin depositional feature in a passive continental margin. Geochemical tectonic discrimination diagrams, based on a major and trace element Ti/Zr–La/Sc plot, in combination with a detrital zircon age distribution pattern, all suggest a passive continental margin setting. Considering this together with the previous data, we argue that the Paleo-Tethys Ocean did not begin to subduct northward and that there was no oceanic subduction zone in the south EKO during Carboniferous to Early Permian times. Combining this information with that from previous studies suggests that the initial opening of the Paleo-Tethyan Ocean may have occurred before the Early Carboniferous time, and all the branches of the Paleo-Tethys Ocean constituted a complex ocean–continent configuration across parts of what is now Asia during the Early Carboniferous to Early Permian. |
| first_indexed | 2024-03-11T06:09:03Z |
| format | Article |
| id | doaj.art-22f45ea052404f35bad6b516f81d117e |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-11T06:09:03Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-22f45ea052404f35bad6b516f81d117e2023-11-17T12:46:50ZengMDPI AGMinerals2075-163X2023-02-0113331210.3390/min13030312Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and GeochronologyXiao Wang0Xianzhi Pei1Ruibao Li2Chengjun Liu3Lei Pei4Zuochen Li5Youxin Chen6Meng Wang7School 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, 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, 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 formation of the East Kunlun Orogen (EKO) was related to the tectonic evolution of the Proto-Tethys and Paleo-Tethys Oceans. However, how the Paleo-Tethys Ocean transited from the Proto-Tethys Ocean, and whether the Paleo-Tethys Ocean subducted northward beneath the East Kunlun–Qaidam Terrane in Carboniferous to Permian times, is still highly debated. Early Carboniferous Halaguole and Late Carboniferous to Early Permian Haoteluowa formations are extensively outcropped in the EKO, north Tibetan Plateau, and have thus recorded key information about the tectonic processes of the Paleo-Tethys Ocean that have implications for the reconstruction of the Northern Paleo-Tethys Ocean (Buqingshan Ocean). Siliciclastic rocks within these formations are collected for petrogeological, geochemical, and detrital zircon U–Pb dating research. Our results show that sandstones from Halaguole and Haoteluowa formations have an average total quartz–feldspar–lithic fragment ratio of Q<sub>67</sub>F<sub>12</sub>L<sub>21</sub> and Q<sub>50</sub>F<sub>20</sub>L<sub>30</sub>, respectively, indicating relatively high compositional maturity. The geochemical results suggest that the average values of the Chemical Index of Alteration (CIA) are 57.83 and 64.66; together with their angular to subangular morphology, this indicates that their source rocks suffered from weak weathering and the sandstones are the result of proximal deposition. Geochemical features such as the low La/Th, TiO<sub>2</sub>, and Ni values suggest that the parental rocks in the provenance area are mainly acidic igneous rocks with minor intermediate igneous and old sedimentary components. The detrital zircon U–Pb age spectrum of these samples is dominated by age peaks at ~405–503 Ma and ~781–999 Ma, with subordinate age peaks at ~1610–2997 Ma and ~1002–1529 Ma, which show tectono–thermal events similar to those of the North Qimatag Belt (NQB), North Kunlun Terrane (NKT), and South Kunlun Terrane (SKT). These features suggest a contribution from the Early Paleozoic magmatic arc and Proterozoic basements in the NQB, NKT, and SKT to the Halaguole and Haoteluowa formations in these areas. In addition, the youngest zircon age of ~440 Ma from these sandstones is greater than the depositional age of Halaguole and Haoteluowa formations, which is a typical basin depositional feature in a passive continental margin. Geochemical tectonic discrimination diagrams, based on a major and trace element Ti/Zr–La/Sc plot, in combination with a detrital zircon age distribution pattern, all suggest a passive continental margin setting. Considering this together with the previous data, we argue that the Paleo-Tethys Ocean did not begin to subduct northward and that there was no oceanic subduction zone in the south EKO during Carboniferous to Early Permian times. Combining this information with that from previous studies suggests that the initial opening of the Paleo-Tethyan Ocean may have occurred before the Early Carboniferous time, and all the branches of the Paleo-Tethys Ocean constituted a complex ocean–continent configuration across parts of what is now Asia during the Early Carboniferous to Early Permian.https://www.mdpi.com/2075-163X/13/3/312East Kunlun OrogenCarboniferousPaleo-Tethys Oceanpassive continental margindetrital zircon U–Pb ageprovenance analysis |
| spellingShingle | Xiao Wang Xianzhi Pei Ruibao Li Chengjun Liu Lei Pei Zuochen Li Youxin Chen Meng Wang Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology Minerals East Kunlun Orogen Carboniferous Paleo-Tethys Ocean passive continental margin detrital zircon U–Pb age provenance analysis |
| title | Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology |
| title_full | Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology |
| title_fullStr | Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology |
| title_full_unstemmed | Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology |
| title_short | Tectonic Background of Carboniferous to Early Permian Sedimentary Rocks in the East Kunlun Orogen: Constraints from Geochemistry and Geochronology |
| title_sort | tectonic background of carboniferous to early permian sedimentary rocks in the east kunlun orogen constraints from geochemistry and geochronology |
| topic | East Kunlun Orogen Carboniferous Paleo-Tethys Ocean passive continental margin detrital zircon U–Pb age provenance analysis |
| url | https://www.mdpi.com/2075-163X/13/3/312 |
| work_keys_str_mv | AT xiaowang tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT xianzhipei tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT ruibaoli tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT chengjunliu tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT leipei tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT zuochenli tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT youxinchen tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology AT mengwang tectonicbackgroundofcarboniferoustoearlypermiansedimentaryrocksintheeastkunlunorogenconstraintsfromgeochemistryandgeochronology |