TY - JOUR
T1 - Evaluating fluvial terrace riser degradation using LiDAR-derived topography
T2 - An example from the northern Tian Shan, China
AU - Wei, Zhanyu
AU - Arrowsmith, Ramon
AU - He, Honglin
N1 - Funding Information:
We are especially grateful to Sotirios Kokkalas, Jie Chen and an anonymous reviewer for helpful suggestions and comments that substantially improved the original manuscript. This research was supported by the Natural Science Foundation of China (Grant Number: 41302173 ) and special funds from China Earthquake Administration for active fault mapping (Grant Number: 201308001 ).
PY - 2015/6/1
Y1 - 2015/6/1
N2 - The morphological degradation of fluvial terrace risers provides a constraint to terrace chronology. In this study, we morphologically date the terrace risers along the Kuitun River on the north flank of the Tian Shan, China and subsequently discuss possible relationships between terrace formation and the past regional climate changes and tectonic activity of the Dushanzi fault-related fold. To do this, 159 topographic profile swaths of terrace risers were extracted from LiDAR-derived DEM and were analysed to determine a range of best fitting morphological ages. Through Monte Carlo simulation, a locally applicable sediment transport coefficient (diffusivity) was calibrated as 5.5±1.6m2/ky given the morphological age of the T1/T2 riser and its independently known age. Taking this calibrated coefficient, we estimate age ranges of 11.6±3.4ka, 6.5±1.4ka, 5.3±1.1ka, and 4.2±1.2ka for terraces T3, T4, T5, and T6, respectively, under the assumption that the age of the riser is close to the abandonment age of the lower surface. These new terrace ages, combining climate proxy records from the oxygen isotope curve from the Guliya ice cap and paleoearthquake events in the Dushanzi fault related fold, suggest that tectonic activity may be an important factor in the formation of lower terraces within the growing anticlines, while in more extensive areas beyond anticlines, climate changes controlled the main deposition and incision events in the present study area, and thus terrace formation of T1-T3.
AB - The morphological degradation of fluvial terrace risers provides a constraint to terrace chronology. In this study, we morphologically date the terrace risers along the Kuitun River on the north flank of the Tian Shan, China and subsequently discuss possible relationships between terrace formation and the past regional climate changes and tectonic activity of the Dushanzi fault-related fold. To do this, 159 topographic profile swaths of terrace risers were extracted from LiDAR-derived DEM and were analysed to determine a range of best fitting morphological ages. Through Monte Carlo simulation, a locally applicable sediment transport coefficient (diffusivity) was calibrated as 5.5±1.6m2/ky given the morphological age of the T1/T2 riser and its independently known age. Taking this calibrated coefficient, we estimate age ranges of 11.6±3.4ka, 6.5±1.4ka, 5.3±1.1ka, and 4.2±1.2ka for terraces T3, T4, T5, and T6, respectively, under the assumption that the age of the riser is close to the abandonment age of the lower surface. These new terrace ages, combining climate proxy records from the oxygen isotope curve from the Guliya ice cap and paleoearthquake events in the Dushanzi fault related fold, suggest that tectonic activity may be an important factor in the formation of lower terraces within the growing anticlines, while in more extensive areas beyond anticlines, climate changes controlled the main deposition and incision events in the present study area, and thus terrace formation of T1-T3.
KW - Diffusion model
KW - Fluvial terrace
KW - LiDAR
KW - Tian Shan
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U2 - 10.1016/j.jseaes.2015.02.016
DO - 10.1016/j.jseaes.2015.02.016
M3 - Article
AN - SCOPUS:84939977186
SN - 1367-9120
VL - 105
SP - 430
EP - 442
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
ER -