37°14′10″N 105°42′50″E / 37.236°N 105.714°E The Zhongwei-Tongxin fault or Tianjingshan fault is an arcuate sinistral (left-lateral) strike-slip zone, forming one of the major structures on the northeastern margin of Tibetan plateau. Six paleoearthquake events in the past 14,000 years have been recorded along the Zhongwei-Tongxin fault zone.[1] Among the earthquakes recorded are the 1622 North Guyuan earthquake, which had a magnitude of 7.0 and mid-seismogenic depth of about 15 kilometres (9.3 mi),[2] the 1709 Zhongwei earthquake, which had a magnitude of 7.5.[1]