Latest Quaternary rapid river incision across an inactive fold in the northern Chinese Tian Shan foreland
- This work focuses on the incision process over the Tuostai anticline, a fold of the proximal structure Belt I in the northern Chinese Tian Shan foreland, where the Sikeshu River has incised deeply into the alluvial gravels and the fold's underlying bedrock strata. Field investigation and geomorphic mapping define five terraces of the Sikeshu River (designated as T1 to T5 from oldest to youngest) preserved within the Tuostai anticline. 10Be surface exposure dating and optically stimulated luminescence dating constrain stabilization of the highest three terrace surfaces at about 80 ka (T1), 16 ka (T2), and 15 ka (T3), respectively. Around 16 ka, the calculated river incision rates significantly increase from <2 mm/yr to >6 mm/yr. Undeformed longitudinal profiles of terraces T2, T3 and T4 over the Tuostai anticline suggest that this structure may have been tectonically inactive since stabilization of these three terraces. We thus think that the observed rapid river incision over the Tuostai anticline has not been largely forced byThis work focuses on the incision process over the Tuostai anticline, a fold of the proximal structure Belt I in the northern Chinese Tian Shan foreland, where the Sikeshu River has incised deeply into the alluvial gravels and the fold's underlying bedrock strata. Field investigation and geomorphic mapping define five terraces of the Sikeshu River (designated as T1 to T5 from oldest to youngest) preserved within the Tuostai anticline. 10Be surface exposure dating and optically stimulated luminescence dating constrain stabilization of the highest three terrace surfaces at about 80 ka (T1), 16 ka (T2), and 15 ka (T3), respectively. Around 16 ka, the calculated river incision rates significantly increase from <2 mm/yr to >6 mm/yr. Undeformed longitudinal profiles of terraces T2, T3 and T4 over the Tuostai anticline suggest that this structure may have been tectonically inactive since stabilization of these three terraces. We thus think that the observed rapid river incision over the Tuostai anticline has not been largely forced by tectonic uplift. Instead, the progressively warmer and wetter palaeoclimatic condition within the Tian Shan range and its surrounding area during the period of ∼20–10 ka may have enhanced river incision across the Tuostai anticline. A reduced sediment/water ratio might have lowered the gradient of the Sikeshu River.…
Verfasserangaben: | Honghua LuORCiD, Lu Cheng, Zhen Wang, Tianqi Zhang, Yanwu Lu, Junxiang Zhao, Youli Li, Xiangmin Zheng |
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DOI: | https://doi.org/10.1016/j.quascirev.2017.10.017 |
ISSN: | 0277-3791 |
Titel des übergeordneten Werks (Englisch): | Quaternary science reviews : the international multidisciplinary research and review journal |
Verlag: | Elsevier |
Verlagsort: | Oxford |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Datum der Erstveröffentlichung: | 15.12.2017 |
Erscheinungsjahr: | 2017 |
Datum der Freischaltung: | 04.04.2022 |
Freies Schlagwort / Tag: | Fluvial terrace; Late Quaternary; Palaeoclimate; River incision; Tian Shan |
Band: | 179 |
Seitenanzahl: | 15 |
Erste Seite: | 167 |
Letzte Seite: | 181 |
Fördernde Institution: | Natural Science Foundation of ChinaNational Natural Science Foundation of China [41371031, 41001002]; Scientific Training and Capability Promotion Project of the National Science Base for Geography [J1310028] |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer Review: | Referiert |