ESR dating of Helan Mountain Fault Zone

It is very difficult to form new metamorphic minerals in the movement of brittle faults under shallow and low-temperature situation. Therefore it is impossible to determine the active ages of faults exactly through traditional methods. In the activation of shallow faults, homochromous quartz veins often develop. As a result, we can use thermal activated ESR dating to obtain the ages of quartz veins, and then to determine the active ages of faults. If there are several stages of quartz veins in fault belts, the corresponding active ages of faults can also be determined. The western Ordos thrust-fold belt has a complicated structure, and its development mechanism is still controversial. A case study was made in the Helan Mountain area. According to the ESR dating of quartz veins, the SN-trending fault which thrusted from east to west in the study area was formed after the Late Jurassic, and experienced several active stages.