Applying the OSL to determine the slip-rate of the Abr Fault
عنوان دوره: بیستمین کنفرانس ژئوفیزیک ایران
کد مقاله : 1893-NIGS
نویسندگان
1موسسه ژئوفیزیک دانشگاه تهرات
2موسسه ژئوفیزیک
3گروه زلزله شناسی
4موسسه ژئوفیزیک دانشگاه تهران
چکیده
The Abr fault is one of the left-lateral strike-slip faults in the southeast of the Alborz Mountains. Previously, by means of Cosmogenic Nuclide dating (TCN- ages of boulders samples 90-100 ka), the cumulative displacement and the slip-rate of the fault were calculated as 400 m and 3-4 mm yr-1, respectively. We decided to employ OSL for determining the slip rate. To compare the OSL and TCN ages, we chose our sampling location close to the sampling location (the Q3 unit) of Javidfakhr et al. (2011). However, the ages obtained from sediments using the OSL method were much younger (22 ka) than the ages from boulders using the TCN method. This suggest that the layer which was used for OSL dating was created after the abandonment of the Q3 unit, and possibly this layer exist in that region, and therefore, according to the new displacements of the region, which is about 60 meters, the slip-rate has been calculated 2.7 mm yr-1, which is slightly lower than the slip rate calculated by the TCN dating method (3-4 mm yr-1).
The OSL provides the age of a much younger layer.
The OSL provides the age of a much younger layer.
کلیدواژه ها
Title
Applying the OSL to determine the slip-rate of the Abr Fault
Authors
zahra aghabeigi boldaji, morteza fattahi, H. Amini, Mohammad reza Hatami
Abstract
The Abr fault is one of the left-lateral strike-slip faults in the southeast of the Alborz Mountains. Previously, by means of Cosmogenic Nuclide dating (TCN- ages of boulders samples 90-100 ka), the cumulative displacement and the slip-rate of the fault were calculated as 400 m and 3-4 mm yr-1, respectively. We decided to employ OSL for determining the slip rate. To compare the OSL and TCN ages, we chose our sampling location close to the sampling location (the Q3 unit) of Javidfakhr et al. (2011). However, the ages obtained from sediments using the OSL method were much younger (22 ka) than the ages from boulders using the TCN method. This suggest that the layer which was used for OSL dating was created after the abandonment of the Q3 unit, and possibly this layer exist in that region, and therefore, according to the new displacements of the region, which is about 60 meters, the slip-rate has been calculated 2.7 mm yr-1, which is slightly lower than the slip rate calculated by the TCN dating method (3-4 mm yr-1).
The OSL provides the age of a much younger layer.
The OSL provides the age of a much younger layer.
Keywords
Abr fault, Slip-rate, OSL