The analysis of tectonic evolutionary stages serves as the basis for addressing the basin formation and evolution

also as the important foundation for delineation of the spatial-temporal framework for oil and gas accumulation

and as a key reference for establishing the tectonic movement chronology for continents.Based on the information from deep boreholes and the high resolution reflection seismic data within the Junggar Basin

we delineated the tectonic evolution stages of the basin and explored the characteristics of every stage

through analyzing the tectonic subsidence and the tectono-stratigraphic sequence

and the tectonic events in the periphery of the basin.The results show that the basin has undergone six evolutionary stages

including the Carboniferous fault depression-depression

the Permian fault depression

the Middle Permian and Triassic foreland basin

the Jurassic extensional fault depression-compresso-shear basin

the Cretaceous-Paleogene intra-continental depression

and the Neogene-Quaternary intra-continental foreland basin

which can be grouped into four non-isochronous extension-compression cycles

namely the Carboniferous

Early Permian-Triassic

Jurassic

and Cretaceous-Quaternary cycles.The extension tends to be weaker

but the compression gets stronger north-southwardly

with time passing by.On the whole

the basin exhibits the character of "thrusting on its periphery and shrinking in scope"

with the west-eastward shortening rate being 35.8%

almost three times of the 12.2% on the north-south direction.The compression from the west took place mainly during the Middle Permian-Early Triassic

while besides that

the compression from the east was still strong in the Late Triassic

early Middle Jurassic

and Late Jurassic-Early Cretaceous.The compression from the south took place strongly in the Middle and Late Permian

the Middle and Late Jurassic

and the Pliocene-Quaternary; while the extensive thrusting on the northern margin occurred in the Late Cretaceous.The pronounced spatial-temporal differences of the above extension and compression have given rise to the complex superimposed composite basin architecture

thus different tectonic units show strong differential evolution and unique features of oil and gas accumulation.