Normal faults in an accretionary complex formed at trench-trench-ridge triple junction, as an indicator of angle between the trench and subducted ridge |
| |
| Authors: | Soichi Osozawa |
| |
| Institution: | Institute of Geology and Paleontology, Faculty of Science, Tohoku University, Sendai 980, Japan |
| |
| Abstract: | Abstract Normal faults parallel to the trend of an active ridge are formed in the accretionary prism at trench-trench-ridge triple junction, due to continuous spreading of the subducted ridge. Normal faults are observed in the Nabae and Mugi sub-belts, accretionary zones formed by ridge subduction in the Shimanto Belt. Igneous and sedimentary dykes intrude through the previous normal faults. Using these fault and dyke data, intermediate principal axis of stress relating to the normal faulting is determined, and is fitted to the trend of the subducted ridge. Normal faults formed by ridge subduction are useful for plate reconstruction. |
| |
| Keywords: | continuous spreading normal faults plate reconstruction ridge subduction |
|
|
