The tectonic style and evolution history of Haimiluosi fault zone

one of the boundary faults of Bachu uplift

can reflect the origin and process of the Bachu uplift formation

which will serve as a basis for exploring the intra-cratonic structural deformation mechanisms.Based on the fault-related fold theories

we analyzed the geometrical characteristics of several two-dimensional seismic profiles cutting through the Haimiluosi fault zone

and depicted the three-dimensional spatial distribution of the faults.Moreover

the tectonic activity of the fault zone was discussed according to the fault displacement and the amount of structural shortening on the profile.And the evolutionary features of faults on profiles were reconstructed using the balanced section technique.The results show that the Haimiluosi fault zone takes the shape of a broom on map

and is characterized by a three-layer structural deformation style on profile.Among them

the Cenozoic and Paleozoic faults take the Paleogene gyprock and Middle Cambrian saline rock as detachment surfaces respectively.The fault zone is located at the break along the strike of the southern boundary fault

accommodating the fault displacement at both ends of the southern fault

and features thrusting-strike-slipping on the whole.Besides

the zone formed through late inversion of the normal faults

that is

normal faults got inversed during the Middle and Late Ordovician due to the Caledonian movement

leading to the initiation of thrust fault and the mild uplifting of the deposited strata.At the end of Late Permian

the early faults reactivated and kept intensive activity for a long time.Subsequently

the Cenozoic boundary faults were formed mainly during the Eocene to Oligocene

and the fault zone reactivated and finalized gradually under the influence of Himalayan movement in the Quaternary.