三江盆地构造演化分析

中生代以来,三江盆地总体处于弧后扩张与走滑的应力场环境,这一大地构造背景对三江盆地的构造演化有重要的控制作用。燕山晚期以来,晚侏罗世-晚白垩世,三江盆地进入扭张性断陷-坳陷盆地的发展时期,新生代,由于依兰-伊通断裂带和密山-敦化等断裂带的联合走滑作用,统一的三江盆地才得以形成。研究表明,三江盆地的构造演化经历晚侏罗世裂陷发展阶段、早白垩世断陷发展阶段、晚白垩世坳陷发展阶段和新生代统一盆地阶段。三江地区相继发育了绥滨坳陷、前进坳陷、汤原坳陷,以及其间的富锦隆起和佳木斯隆起,在发生-发展上存在着一定的差异,只有到了新生代才成为统一的三江盆地。盆地构造演化控制了沉积和油气成藏特点,绥滨坳陷下部沉积建造厚大,并以其海陆交互相煤系为特征,因而对成气有利。前进坳陷下部构造层的滨海相含煤建造,对成气有利;上部构造层较厚的河湖相砂泥岩建造,对成油有利。

Analysis on the structural evolution of Sanjiang Basin

After Mesozoic Era,Sanjiang Basin was in setting of the back arc spreading and striking slip,which significantly controlled its structural evolution.After Late Yanshan Movement,during the time of Late Jurassic and Late Crataceous,Sanjiang Basin entered the period of faulted basin and depression basin;and during the time of Cenozoic era,because of the combined acting of Yilan-Yitong fault and Mishan-Dunhua fault,the unified Sanjiang Basin was formed.Research indicated that Sanjiang Basin experienced four the structural evolution stages,such as rifted period,faulted period,depression period and unified period.Sanjiang Bsain successively developed three depressions and two uplifts which occurred and developed differently,and till Cenozoic era,it became the unified basin.The structural evolution controls deposition and pool-forming.The under stratum in Suibin basin is favorable for gas pool-forming because of its thick paralic coal measure strata.The under stratum in Qingjin basin is also favorable for gas pool-forming,but the upper stratum is favorable for oil pool-forming because of its thick fluviolacustrine sandstone and mudstone.