松辽盆地北部大庆长垣南端上白垩统四方台组物源体系分析

Provenance system of the Late Cretaceous Sifangtai Formation in the south of Daqing placanticline of the northern Songliao Basin

物源体系制约着层间水的流动方向及砂体储层的展布。前人对松辽盆地北部上白垩统物源体系分析多集中在四方台组以下,缺乏对四方台组物源的报道。因此,在结合区域地质认识的基础上,通过沉积构造分析、砂体展布形态及重矿物分析等手段,系统研究了松辽盆地北部大庆长垣南端四方台组物源体系特征,明确了物源方向与母岩类型。结果表明,四方台组地层的母岩类型主要为中酸性岩浆岩与中高级变质岩;通过与源区对比分析,认为大庆长垣南端四方台组物源主要来自张广才岭、吉黑东部及盆地东南部地区。

The provenance system restricted the flow direction of interlayer water and the distribution characteristics of sandstone reservoirs. The previous analysis of the upper Cretaceous provenance system in the northern Songliao Basin was focused below the Sifangtai Formation,and there was a lack of reports on the origin of the Sifangtai Formation. We systematically studied the characteristics of source systems of the Sifangtai Formation at the southern end of Daqing placanticline in the northern Songliao Basin using regional geological understanding,through sedimentary structural analysis,sand body distribution pattern and heavy mineral analysis,and identified the source direction and parent rock type. The results showed that the main parent rocks of the Sifangtai Formation are intermediate acid magmatic rocks and intermediate and high-grade metamorphic rocks. Through contrast analysis with the source regions,it was concluded that the provenance of the Sifangtai Formation in the south of Daqing placanticline was mainly from the Zhangguangcai Ranges,the eastern Jilin-Heilongjiang provinces and the southeastern region of the basin.