宣化煤田位于张家口市宣化区的东南,为一侏罗系含煤盆地。煤系地层极不稳定,且煤系上覆地层中普遍发育一至多层较厚的火成岩,弹性波速度较高,有较强的屏蔽作用。这样的地区,多年来一直被封为地震勘探的“禁区”。随着多次覆盖和数字处理技术的出现,地震勘探技术有了明显的发展,其地质效果亦大为改观。但对于上述的所谓“禁区”效果又将如何呢?我们带着上述问题在宣化煤田进行了地震试验。结果说明,类似这类地区经过努力是可以获得较好的地 Xuanhua Coalfield is located in the southeast of Zhangjiakou City Xuanhua District, a Jurassic coal-bearing basin. Coal-bearing strata are extremely unstable. One or more layers of thick igneous rocks are generally developed in overlying strata of coal measures, and the elastic wave velocity is relatively high with strong shielding effect. Such areas have for many years been labeled “exclusion zones” for seismic exploration. With the advent of multiple coverage and digital processing technologies, the seismic exploration technology has been significantly developed and its geological effects have also been greatly improved. But what about the so-called “closed area” effect mentioned above? We conducted the earthquake test at Xuanhua Coalfield with the above problems. The results show that similar efforts in such areas can get better