苑城地堑的阻水性研究

Study on Yuancheng Graben Water Resistance Property

苑城地堑作为百泉岩溶水系统和黑龙洞泉岩溶水系统的地下分水岭存在争议,主要原因是由于苑城地堑的阻水性论证缺少数据支持。本次研究主要通过地面瞬变电磁勘探、磁法勘探、地质钻探、水位与水质分析等多种方法进行综合论证。地面瞬变电磁勘探结果显示,苑城地堑北侧电阻率高,南侧电阻率,南北两侧水力联系弱;通过磁法勘探发现,苑城地堑北部岩浆岩发育异常,南侧未见岩浆岩发育;地质钻探验证了岩浆沿北部断层侵入弱结构面地层中;对地堑两侧的奥灰水位及水质分析结果显示,地堑两侧的水位及水质有差异,进一步说明了地堑两侧水力联系不明显。综合分析认为,苑城地堑具有良好的阻水性能,阻水性能主要源于北部断层的阻水性及岩浆岩的侵入作用。

Controversy is existed in if the Yuancheng graben is the groundwater divide between Baiquan karst water system and Hei- longdongquan karst water system, due to the graben water resistance property lack of data support. The study has carried out compre- hensive demonstration through surface TEM, magnetic prospecting, geological drilling, water level and water quality test multiple meth- ods. The result from surface TEM prospecting has shown that resistivity in north side of Yuancheng graben is high, south side low, hy- draulic connection between the two sides is weak. Through magnetic prospecting has found that magmatic rock is unusually developed in northern part of the graben, but unseen in south side. Geological drilling has verified that the intrusion of magmatic rock is along the faults in north part into strata with weak structural planes. The analyses of Ordovician limestone water level and water quality have shown that water level and water quality of both sides are different, that further explained the unconspicuous hydraulic connection between the two sides. The comprehensive analysis has considered that Yuancheng graben has good water resistance property mainly derived from magmatic intrusion.