DETERMINATION OF SLIP RATE ON THE SOUTHERN SEGMENT OF THE ANNINGHE FAULT |
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| Authors: | WANG Hu RAN Yong-kang CHEN Li-chun LIANG Ming-jian GAO Shuai-po LI Yan-bao XU Liang-xin |
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| Institution: | 1.Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China;2.Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China;3.Division of Medium to Long-Term Earthquake Prediction, Institute of Geology, China Earthquake Administration, Beijing 100029, China |
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| Abstract: | The Anninghe Fault has been suggested as an important segment of the fault system along the eastern boundary of the Sichuan-Yunnan faulted block in the southeastern region of the Tibetan plateau. Reliable determination of the Late Quaternary slip rate on the Anninghe Fault is very helpful and significant for revealing deformation mechanism and kinematic characteristics of the Sichuan-Yunnan faulted block, which further helps us understand fault activity and seismic potential of the region. However, previous studies were focused mainly on the northern segment of the Anninghe Fault, while slip rate on its southern segment has been less studied. Therefore, in this paper, we chose two sites at Dashuigou and Maoheshan on the southern segment of the Anninghe Fault, and used high-resolution images of unmanned aerial vehicle (UAV)photogrammetry technology, detailed field survey, multiple paleoseismic trenching and radiocarbon dating methods to constrain slip rate on the southern fault segment of the Anninghe Fault. Specifically, we suggest that the slip rate at the Dashuigouo site is narrowly constrained to be~4.4mm/a since about 3￣￣300a￣￣BP based on a linear regression calculation method, and speculate that a slip rate of 2.6~5.2mm/a at the Maoheshan site would be highly possible, although we poorly constrained the whole deformation amount of the two branch faults at the Maoheshan site from multiple paleoseismic trenching. The data at the two sites on the southern segment show a consistent slip rate compared with that of the northern segment of the Anninghe Fault. Moreover, considering a similar paleoseismic recurrence interval on the two segments of the Anninghe Fault from previous studies, we further suggest that the fault activity and deformation pattern on the two segments of the Annignhe Fault appears to be well consistent, which is also in agreement with the regional tectonic deformation. |
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| Keywords: | Tibetan plateau the Sichuan-Yunnan faulted block the Anninghe Fault slip rate |
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