高位火山岩的圈定及其顶部埋深和厚度的计算方法

在油气勘探的盆地中经常发育有火山岩。火山岩的存在给油气勘探工作带来相当大的困难，尤其是高位火山岩的存在使得地震勘探难以取得品质较好的资料，同时高位火山岩与相邻地层有较大的密度差产生一定的重力异常效应，对应用重力研究盆地的基地深度带来相当大的误差。因此，探索高位火山岩的圈定及其顶部埋深和厚度的计算方法尤为重要。提出了应用航磁资料结合高位火山岩的磁异常特点圈定和计算高位火山岩的顶部埋深和厚度的计算方法并在漠河盆地的早期评价中得到了很好的应用，也解决了高位火山岩顶部埋深和厚度计算的难题，具有一定的推广应用价值。

Outlining of High Volcanic Rocks and the Calculation Method for Their Top Buried Depth and Thickness

Constantly, there are volcanic rocks developed in basins for oil and gas exploration. The volcanic rocks cause great difficulty to hydrocarbon exploration. Especially when there are high volcanic rocks it is difficult to obtain higher quality data during seismic exploration. There are greater density difference between the high vol-canic rocks and the adjacent formation, and this difference can result in gravity abnormal effect. So, errors will occur when the gravity is applied to research the base depth of one basin. Therefore, it is very important to study on the outlining of high volcanic rocks and the calculation method for their top buried depth and thickness. It is supposed that with the combination of aeromagnetic data with the abnormal magnetic feature of high volcanic, rocks the top buried depth and thickness can be calculated. This method was well applied to the early evaluation of Songliao basin. It is also one method to solve the problem to calculate the top buried depth and thickness of high volcanic rocks, and it has certain potential to be widely used.