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Titel |
Late Quaternary right-lateral slip rates of active faults adjacent to lake Qinghai, northeastern margin of the Tibetan Plateau |
VerfasserIn |
D.-Y. Yuan, J.-D. Champagnac, W.-P. Ge, P. Molnar, P.-Z. Zhang, W.-J. Zheng, H.-P. Zhang, M.-J. Liang |
Konferenz |
EGU General Assembly 2009
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 11 (2009) |
Datensatznummer |
250020910
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Zusammenfassung |
Combining the terrace riser offsets with terrace ages dated by 14C, OSL and 10Be techniques, we determine average strike slip rates of Elashan and Riyueshan faults, two north-northwest-trending strike-slip faults along the western and eastern sides of the lake Qinghai, northeastern margin of the Tibetan plateau, to be about 1.0 ± 0.2 mm/yr and 1.2 ± 0.2 mm/yr, respectively.
Between them, the Qinghainanshan fault consists of three secondary thrust faults, whose total vertical slip rate and shortening rate are ~0.4-1.0 mm/yr and ~0.2-1.2 mm/yr, respectively.
The relatively low slip rates in this region reflect distributed deformation. The total right-lateral offsets of the geological contacts, which were interpreted from 1:200,000-scale Qinghai regional geological maps of the region, are about 8.8-11.9 km along the Elashan fault and 10.9-11.6 km for the northern segment of Riyueshan fault. If long–term slip rates were constant during late Cenozoic time, initiation of dextral movement would be 10.3 ± 3.6 Ma and 9.4±2.3 Ma for the two strike-slip faults, consistent with records of tectonic deformation in Cenozoic basins nearby.
Our study highlights a stage of tectonic deformation in the northeastern margin the Tibetan plateau beginning near ~10 Ma, long after the collision between India and Eurasia began.
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