关键词: 关键词, 东秦岭, 铁炉子断裂, 新活动

Abstract: This paper describes the pattern and appearance of the recent activity of the Tieluzi Fault and recent stress field in East Qinling Mountains. The recent movement of the Tieluzi Fault has resulted in the "S"-shaped turning of streams, displacement of terraces and Neogene sediments along the fault. The recent stress field over the East Qinling Mountains was dominated by SEE-trending compressive stress. The amplitude and rate of faulting were determined on the basis of the differences of elevation, lateral displacements and ages of terraces. From our investigations and measurements, the following conclusions can be drawn: 1) The recent movement of the Tieluzi Fault was dominated by left-lateral strike-slipping. Since the formation of the third terrace, the left-lateral offset along the Tieluzi Fault amounted to several hundreds meters, while its total vertical displacements were within 30 meters. It means that the lateral movement was at least a factor of magnitude larger than the vertical movement; 2) The Tieluzi Fault displayed apparent vertical movements at the places where basins were developed, while at the places where no basin was developed, its vertical movement was relatively weak; 3) The recent movement of the Tieluzi Fault seems to have accelerated since the formation of the third terrace. For example, the rate of lateral displacement of the Tieluzi Fault was in the range of 5～7mm/a since the formation of the third terrace, while since the formation of the first terrace, it was in the range of 8～12mm/a. It is suggested that the recent movement of the Tieluzi Fault was the result of northward squeezing of the Indian Plate beneath the Eurasian Plate, as suggested by Tapponnier et al (1990), and that the recent movement of the Tieluzi Fault reflects the eastward or southeastward differential movement of East China blocks.

Key words: East Qinling Mountain, The Tieluzi Fault, Recent activity