He Zhiliang, Liu Jishun. PETROLEUM GEOLOGICAL CONDITION AND EXPLORATION DIRECTION OF QINGZANG PLATEAU[J]. 1996, 17(2): 87-95.DOI: 10.11743/ogg19960201.
Qingzang Plateau is an important part of Tethys domain between paleo-Eurasia and Gandwana. The petroleum geological condition there is complicated due to the regional framework of nearly E-W trending arc faults alternated with faulted terrains
the complex crust-mantle architecture and intensive neotectonic movements within the plateau. Since Cambrian
the plateau has undergone multi-cyclic geological evolution of four major stages: Proterozoic ocean
palaeo-Tethys
new Tethys and indian Ocean. The composition and overlapping of the prototype basins in different places and different periods within the plateau formed potential oil-bearing regions. Among them
Northern Himalaya is composed of overlapped cratonic depression-intercontinental rift-passive continental margin-peripherral foreland basin: the Northern Gangdise is composed of superposed cratonic rift depression-back arc basin-remnant back are basin-strike slip pull apart basin : Northern and Southern Qiangtang consist of superimposed cratonic rift depression-quasipassive continental margin-strike slip and compressional basin
and cratonic depression-passive continental margin-peripheral foreland basin and strike slip basin respectively. On the setting of intensive compressional deformation and uplifting
the basins show unique stratigraphic distribution
tectonic framework and structural patterns
and complex oil-gas-water system. Various blocks in the plateau have multiset of source rocks and reservoirs
but the organic matter of the source rocks is a little overmatured. As the plateau uplifted
the period of high geothermal environment was little later than that of tectonic deformation. This might probably result in secondary oil generation and late stage pooling in some places within the plateau. Mudstones and shales that widely developed there
gypsolyte distributed in local places and permafrost formed multi-type of source-reservoir-cap rock assemblages. Different types of structural
lithologic and sedimentary traps are targets for oil and gas exploration. Strategic break-through in oil and gas exploration could be achieved by selecting stable blocks with fine oil-gas-water system and overlapped basins with favourable matching within the plateau.