黄骅坳陷东部构造带新生代构造沉降史分析

黄骅坳陷东部构造带包括岐东构造带、白东构造带、新港构造带。新生代构造沉降史的恢复是基于对3个井区的回剥分析进行的。构造沉降曲线表明,黄骅坳陷东部构造带在沙河街组沉积时期快速沉降,为裂陷时期。东营组沉积时期,沉降速率减小,为裂陷坳陷过渡时期。馆陶组明化镇组时期,沉降量明显减小,为坳陷时期。对3个构造带位于同一测线上的3口探井的比较表明,南部岐东构造带的QK17-2-1井区新生代构造沉降量最大,中部白东构造带的BD1-1井区构造沉降量次之,北部新港构造带GH3-1井区的构造沉降量最小。盆地构造沉降量的变化趋势基本反映盆地基底的伸张量变化趋势,两者具有正相关关系。而伸展量的大小与裂陷发育的程度具有正相关关系。

ANALYSIS OF CENOZOIC TECTONIC SUBSIDENCE HISTORY OF THE EAST TECTONIC BELTS IN HUANGHUA DEPRESSION

The east tectonic belt of Huanghua Depression includes Qidong,Baidong and Xingang tectonic belts.The reconstruction of the Cenozoic subsidence history of the east Huanghua tectonic belt was made by denuded amount analysis of three boreholes in the basin. The tectonic subsidence curves of the wells show that a rapid tectonic subsidence happened in the study area during Shahejie period,suggesting a rifting phase;a slow tectonic subsidence happened during Dongying period,suggesting a transitional phase of rifting subsiding;Guantao Minghuazhen period was a subsiding phase.The comparison of the three boreholes of the three tectonic belts situated on the same measuring line indicates that Qidong tectonic belt in the south part has the maximum amount of tectonic subsidance;Baidong tectonic belt in the middle is secondary and Xingang tectonic belt in the north part has the minimum amount.The tectonic subsidence trend reflects the extensional amount trend.