辽宁大地构造单元重磁场特征及几个有关问题的讨论

THE CHARACTERISTICS OF GRAVITY AND MAGNETIC FIELD OF GEOTECTONIC ELEMENTS IN LIAONING

辽宁大地构造单元的地球物理场具有多样性和复杂性。笔者根据辽宁大地构造演化和全域重、磁资料将辽宁地区台划分为5个二级构造单元,即辽东台隆、下辽河断陷带、北镇—山海关台隆、燕山台褶带和内蒙地轴。其中北镇—山海关台隆是根据重、磁场特征新确立的二级构造单元。同时,重新确定了下辽河断陷带的范围,讨论了郯庐断裂带的北延走向。资料表明,下辽河断陷带(包括辽东湾、渤海海域)是在郯庐断裂带的基础上发育而成的大陆裂谷系。

The geophysical field of geotectonic elements in Liaoning has the characteristicsof diversity and complex. The authors divide Liaoning into five second-class tectonicelements based on the evolution and data of gravity and magnetism. They are easternLiaoning platform uprise, Lower Liaohe sag zone,Beizhen-Shanhaiguan platform uprise,Yanshan platform fold belt and Inner Mongolia axis, in which Beizhen-Shanhaiguanplatform uprise is the newly-established second-class tectonic element according to thecharacteristics of gravity and magnetism. At the same time,the scope of Liaohe sagzone is determined again;the northern extended strike of Tanlu fault zone is discussed.The data show that the lower Liaohe sag zone including Liaodong Bay, Bohai sea areais the continental rift systerm developed on the base of Tancheng-Lujiang fault zone.