Structural Pattern Analysis of Bayanhaote Basin and Its Significance

Bayanhaote Basin is a multiple-overlapping basin which developed in the crossing zone of Qinlin, Qilian and Helan trifurcate rift system during the early of lower Palaeozoic. Various structural patterns developed in this basindue to its special structural location and complex structural evolution history: compressional structural pattern mainly includes imbricated thrust,back thrust and ramp assemblage;stretching structural pattern principally consists of listric normal fault and tilt block,antithetic fault and rollover anticline, and "horst - graben"structure; strike slip structural pattern mainly are nower-type structure and en echelon fault,additionally, there also developcd structural pattern relevant to gravity and other factors, sucb, as compactional structure and ciapir structure. Different structure patterns are accompanicd with different trap types.It is believed based on comprehensive analysis of the petroleum geological conditions that HeishantouTonggulou anticline structural zone is the most favorable,while Amenzi - Chahan anticline structure takes second place, and that petroleum exploration prospect is bright in this basin.