Oligocene-Early Miocene river incision near the first bend of the Yangze River: Insights from apatite (U-Th-Sm)/He thermochronology
| Autor: | Pieter Vermeesch, James Schwanethal, Xiaoming Shen, Yuntao Tian, Siwei Qin, Dewen Li |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
geography
geography.geographical_feature_category Plateau 010504 meteorology & atmospheric sciences Bedrock Late Miocene 010502 geochemistry & geophysics 01 natural sciences Apatite Thermochronology Paleontology Tectonics Geophysics visual_art Isotope geochemistry visual_art.visual_art_medium Geology 0105 earth and related environmental sciences Earth-Surface Processes River incision |
| Zdroj: | Tectonophysics. 687:223-231 |
| ISSN: | 0040-1951 |
| Popis: | The southeastern Tibetan Plateau is deeply incised by three parallel rivers, the Salween, the Mekong and the Yangtze. The river incision and surface uplift histories of this landscape are hotly debated. This study presents bedrock apatite (U-Th-Sm)/He data from a ~ 1800 m vertical profile, located near the first bend of the Yangtze River. Ages range from 20 to 30 Ma, indicating an Oligocene-Early Miocene phase of moderate river incision at a rate of ~ 0.10–0.18 mm/yr. This is considerably older than elsewhere in the region, but consistent with a previously proposed phase of Eocene surface uplift inferred from stable isotope geochemistry. We consider the implications of the new data under two different tectonic models. If the surface uplift and river incision resulted from lower crustal flow, the new results require such flow to have commenced at Oligocene-Early Miocene time rather than during the previously proposed Late Miocene. Alternatively, Oligocene to Early Miocene plateau growth might have resulted from transpressional deformation in the southeastern Tibetan Plateau. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect