利用位场功率谱计算地质体顶底深度效果

CALCULATING TOP AND BOTTOM DEPTH EFFECT OF GEOLOGICAL BODY BY APPLYING POTENTIAL FIELD POWER SPECTRUM

利用区域重力、磁力资料采用功率谱法可以方便、快捷地得到一个新区或一个盆地的基底起伏、区域磁性层的顶底界面深度。区域磁性界面常常为磁性较强的火山岩顶底界面以及居里面，这对一个新区或一个盆地早期评价中的构造单元划分、资源量计算、区域地温场研究、有利远景区预测等具有重要的意义。应用功率谱法计算地质体顶底深度的可靠性往往与滑动窗口大小、拟合频段的选取有直接关系。研究表明，要计算埋深为ｈ的地质体，窗口的大小应为（４～６）ｈ，拟合频段根据模型实验确定；地质体水平尺寸对计算结果影响不大，起主要影响的是地质体的上顶埋深、地质体的厚度及窗口与地质体的对应程度。

By adopting power spectrum method, the regional gravity and magnetic force data can be used to obtain the basement fluctuation and top, bottom interface depth of regional magnetic layer. The dependence of this method has generally direct relation with the size of sliding window and selection of fitting frequency section; horizontal size of geological body has less effect on calculation result, it is the top depth, thickness of geological body and the corrosponding degree of window with geological body that has the main effect.