准噶尔盆地重磁力场与构造特征分析

摘要

采用归一化总水平导数法对准噶尔盆地重磁力场数据进行了分析.结果表明,归一化总水平导数法能较好地反映磁力场异常区与地质构造的关系.在准噶尔盆地的东北部区域,青格里底山断裂带和克拉美丽断裂带均呈现显著的垂直重力磁力场异常区,在盆地的中部区域存在局部垂直负重磁力场异常区.准噶尔盆地为断陷盆地,断裂带主要分布在盆地的边缘,重磁力场普遍较强.在盆地的中部重磁力场普遍较弱,且存在部分负磁力场异常区.准噶尔盆地中南部地区整体表现为“东西宽,南北窄”的狭长重力负异常区,且在中央坳陷区内存在显著的垂直重力负磁力场异常区,这可能是由火山岩活动造成的.%The normalized total level derivative method is adopted to analyze the gravity magnetic field data.The results show that the normalized total level derivative method can provide a reliable basis about the relationship between the gravity field and fault distribution.It forms a significant vertical gravity magnetic anomaly zone in the northeast area of Junggar basin,the green mountain fault zone and the "Kelameili" fault zone.It exists significant negative local vertical gravity field anomaly area in the central area of the Junggar basin.Besides,it can also be found that the Junggar basin is a fault basin,the fault zones are mainly distributed in the edge of the Junggar basin,in which also exists strong gravity field.On the contrast,there is no obviously gravity field exists in the central basin,where exists negative gravity field in certain part of this area.The overall shape of the anomalous negative gravity field of the south central of Junggar basin presents a "wide length from the east to the west and narrow length from the north to the south",and there is a significant anomalous negative vertical gravity in the central depression area of the Junggar basin,which may be caused by the volcanic activities among these area.