Orogeny of the backbone mountain range of the Korean Peninsula matches with the rapid East Sea opening: Assessment from the mountain range formation using a numerical landscape evolution model
Abstract
The backbone mountain range of the Korean Peninsula develops along the eastern margin of the peninsula with great escarpment facing the East Sea (or Japan Sea). It has been widely accepted that the mountain range has formed gradually by tilted up-warping tectonic movements since the Early Tertiary. However, recent researches into the timing of its orogeny argued that, instead of the steady uplift, the mountain range had built intensively during the Mid Miocene when the East Sea had opened rapidly. To resolve the controversy on the orogenic timing, the formation of mountain range and channel network development were explored theoretically using a numerical landscape evolution model under various tectonic uplift conditions: uniform, impulsive, and fluctuating uplifts. We found that, in the uniform uplift condition, the mean elevation of the model result topography increases and reaches a steady state; the proportion of bedrock channels increases gradually with reduction of alluvial channels. The impulsive uplift condition shows rapid decrease in both the mean elevation and the proportion of bedrock channels, in spite of initial fast growth. In the fluctuating uplift condition, the mean elevation also fluctuates responding to the uplift rate variation, resulting eventually in increases in both the mean elevation and bedrock channels. According to the comparison of the model results with the real landscape across the middle part of Korean Peninsula, the final topography under the impulsive uplift condition is most similar to the real landscape: steep escarpment with high concavity stream profiles and low relief hillslopes along the eastern margin of the peninsula. Therefore, we suggest that the orogeny of the backbone mountain range concentrated on the Mid Miocene, matching with the rapid East Sea opening, and that the mountain range is in a decaying phase rather than a growth phase.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP31C2309B
- Keywords:
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- 1815 Erosion;
- HYDROLOGY;
- 1824 Geomorphology: general;
- HYDROLOGY;
- 8175 Tectonics and landscape evolution;
- TECTONOPHYSICS;
- 8177 Tectonics and climatic interactions;
- TECTONOPHYSICS