Discussion on "multi-laminate structure" of basement in Songliao Basin and its significance

The dating data of magmatic zircons residued from the drilling basement rocks and captured from Mesozoic volcanic rocks in Songliao Basin indicate seven peaks of the forming time in the basin basement,which are about 240 Ma,350 Ma,420 Ma,530 Ma,1 000~1 100 Ma,1 800~1 850 Ma and 2 500 Ma,respectively.Combined with the research on drilling data and paleontological and lithological characteristics,the basement of Songliao Basin can be divided into six structure layers as Variscan,Caledonian,Baikal(Khankan),Sibao,Luliang,Fuping and Qianxi,which shows multi-laminate structure of basement.The fact indicates that the tectonic evolution in this area is consistent with the epicontinental structure of Xingmeng-Jihei orogenic belt,Siberia and North China blocks in Mesozoic.The planning-established Paleozoic lithostratigraplic units in the basement of Songliao Basin can be correlate to the known lithostratigraplic units of the surrounding areas,which benefits expanding the survey and explore scope of oil and gas reservoirs in the periphery and profundity of the basin.