 |
| Titel |
Understanding long-term strain accommodation in the Longmen Shan region: Insights from 3D thermo-kinematic modelling of thermochronometry data |
| VerfasserIn |
Yuntao Tian, Pieter Vermeesch, Andy Carter |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105866
|
| Publikation (Nr.) |
 EGU/EGU2015-5454.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Longmen Shan marks the steep eastern margin of the Tibetan Plateau and three parallel NW-dipping fault zones define its structural geometry. From foreland (southeast) to hinterland (northwest), the main faults are the Guanxian-Anxian fault, Yingxiu-Beichuan fault and Wenchuan-Maowen fault. The exhumation pattern constrained by 1-dimensional modelling made from a compilation of published and unpublished thermochronometry data shows a strong structural control, with highest amounts of exhumation in the hinterland region, a pattern that is characteristic of out-of-sequence thrusting (Tian et al., 2013, Tectonics, doi:10.1002/tect.20043). 3-dimensional thermo-kinematic modelling of these data suggests that the listric Longmen Shan faults merge into a detachment at a depth of ~20-30 km. The models require a marked decrease in slip-rate along the frontal Yingxiu-Beichuan in the late Miocene, whereas the slip-rate along the hinterland Wenchuan-Maowen fault remained relatively constant. These results reveal the long-term pattern of strain accommodation and have important implications for hazard risk assessment in the region. Further, the out-of-sequence thrusting architecture highlights the importance of upper crustal shortening and extrusion in forming this plateau margin. |
|
|
|
|
|
|