【摘要】 应用遥感地质解译、土壤氡气测量、地温测量以及地电测试等技术方法,结合现场勘查和相关地质资料,对成都市龙泉驿点状地热异常现象的成因机制进行探讨。龙泉驿断层被南北向和北东-南西向的次级断层切割,断层遥感影像清晰。断层上方土壤中出现极高的氡气浓度异常,从旁侧向地热异常点逐渐升高,显示断层的活动性和良好的渗透性,沿断层有流体上升。断层上方近地表局部填充的块状疏松土壤起到"导热管"的作用。发震于龙门山逆冲推覆造山带的汶川大地震及其余震的剧烈运动,使成都前陆盆地中的岩块沿中三叠统下部滑脱层滑动,产生大量构造热。热流沿滑脱层向远端的前陆隆起——龙泉山传递,通过龙泉驿断层向上溢流,并经"导热管"在地表形成点状地热异常。龙泉驿地热异常的主导因素是汶川大地震引发的构造热产生的地震地热异常"远端效应"。龙泉山断裂带不可能发生较大的破坏性地震。该地区可能有丰富的地热资源,值得进一步研究。更多还原

【Abstract】 By use of the geologic remote sensing,soil radon measurement,geoelectric survey,ground temperature measurement,in combination with the related geologic information and site survey,this paper studies the mechanism of "spotted geothermal anomaly" in Longquanyi of Chengdu.The Longquanyi fault cut by its secondary faults has trends of N-S and NE-SW.These faults have a clear remote sensing image.The concentration of the soil radon above the faults is very high,moreover,from the exterior to the spotted geothermal anomaly,the concentration of the soil radon heightens gradually.All the evidences indicate that the Longquanyi fault has activities and high permeability and some fluid can rise through this fault.The loose soils locally distributed over the fault work as a "heat pipe".The Wenchuan earthquake was triggered by the Longmenshan overthrust nappy belt.Vigorous movements of the Wenchuan earthquake caused the rocks of the Chengdu foreland basin to dislocate along with the Middle Triassic lower slip horizon and generated a great quantity of structural heat,then the heat transferred along the slip horizon to the Longquanshan Mountain —— the uplift foreland of the Longmenshan nappy structural belts.Finally,the heat could rise through the active Longquanyi fault and come into being spotted geothermal anomaly on the surface with the help of the "heat pipe".The main cause of the geothermal anomalies maybe the earthquake "endpoint effect" of structural heat triggered by the Wenchuan earthquake.No destructive earthquake will happen in Longquanshan,and there will be a good exploration prospect of geotherm.Longmenshan is worth further researching.更多还原