冀中坳陷古近系沙河街组三段中亚段岩相古地理

冀中坳陷古近系始新统沙河街组三段中亚段地层全区广泛分布,在钻井、岩心和地震资料等定性和定量资料基础上,运用灰色关联分析方法得到的各单因素关联主因子,优选出5类与沉积相域展布有关的影响因素:地层厚度、粗碎屑岩含量、细碎屑岩含量、红色泥岩含量及暗色泥岩含量.在此基础上,采用单因素分析多因素综合作图法,编制了各层序格架下的岩相古地理图.冀中坳陷古近系沙三中亚段主要发育的沉积相,包括冲积扇、河流、(扇)辫状河三角洲、近岸湖底扇及湖泊.研究结果表明:沙三中亚段主要发育大型冲积扇河流-(扇)辫状河三角洲湖泊沉积体系,并处在冀中坳陷始新统早期的湖盆断陷扩张深陷期沉积这一演化阶段.

Lithofacies Paleogeography Maps of Paleogene System at Shahejie Formation 3rd Middle Sub-member in Jizhong Depression

The stratum of Paleogene System at Shahejie formation 3rd Middle sub-member in Jizhong depression is universal distribution.On the base of the welldrilling,core and quake data etc.as characterization and quantification,The single factor factor obtained by using the grey association analysis method,in which 5 factors are selected,which are related to the distribution of sedimentary facies,they are:formation thickness,the content of coarse clastic rocks,the content of fine clastic rocks,the content of red mudstone and the content of dark mudstone,by this,the lithofacies paleogeography maps of Paleogene System at Shahejie formation 3rd Middle sub-member in Jizhong depression are compiled with the single factor analysis and multifactor comprehensive mapping method,the stratum of Paleogene System at Shahejie formation 3rd Middle sub-member mainly develops some sedimentary facies including alluvial fan,stream,braided river delta,sublacustrine fan in shore and lake.The result of research shows that the sequence stratum mainly develop umbrella alluvial fanstream braided river delta-lake sedimentary system.Jizhong depression of Paleogen System had gone through the two phases of sedimentary evolvement for the deposit of fault expansive up to the chin age for basin in earlier Eocene Series.