摘要
苏北盆地为中新生代"裂谷型"拉张盆地,沉积了厚度较大的古近系、新近系及第四系地层,其特殊成因,决定了其具有相对较高的大地热流和相对较大的地温梯度,同时也造就了该地区丰富的石油资源及地热资源。苏北盆地地热主要有传导型地热系统(孔隙型地热及构造裂隙型地热)及对流型地热系统,各种类型地热资源的形成及分布皆呈特殊规律。孔隙型地热资源主要呈层状分布,广泛发育于盐城组底部砂、砂砾层中,40℃以上的地热水主要赋存于底界大于800 m的盐城组;构造裂隙型地热资源主要发育于盆地北缘的嘉山—响水断裂、盆地南缘的控盆断裂(如扬州—如皋断裂及金坛—如皋断裂)及建湖隆起两侧弧形断裂构造带等;苏北盆地隆起带边缘浅部松散层存在多个地温异常带,这些异常带与深部隐伏对流型地热资源相关,是深部地热资源的找矿标志,通过对小洋口地热田成因分析,推断盐城市地热异常带之下隐伏着中温地热水资源。
The Subei Basin is a tensional basin of rift type of Mesozoic and Cenozoic ages. Thick sediments of Paleogene,Neogene and Quaternary ages occur in the basin. The special formation of the Subei Basin not only leads to relatively high terrestrial heat flow and geothermal gradient,but also results in rich resources of petroleum and geothermal water in this area. The main geothermal types of the Subei Basin are conduction geothermal system（ pore geothermal and structural fissure geothermal） and convection geothermal systems,presenting special features both in formation and distribution. Pore geothermal resources mainly distribute in layers and extensively develop in the sand and gravel layers in the bottom of the Yancheng Group. The geothermal water over 40 ℃ manly exists in the Yancheng Group with the bottom boundary deep than 800 m.Geothermal resources in structural fissures mainly exist in the Jiashan-Xiangshui fault in the northern margin of the basin,the basin-controlling fault in the southern margin（ e. g.,the Yangzhou-Rugao fault and the JintanRugao fault） and the arc fault structure zone in both sides of the Jianhu uplift. The shallow unconsolidated layers at the edge of the Subei Basin uplift belt contains multiple geothermal anomaly zones,which are related to deep concealed convection geothermal resources and are regarded as the prospecting marks of deep geothermal resources. By analyzing the formation of the Xiaoyangkou geothermal field,it is concluded that geothermal water resources of medium temperature occur under the geothermal anomaly zone in Yancheng.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2015年第4期164-170,共7页
Hydrogeology & Engineering Geology
关键词
苏北盆地
地热资源
成矿规律
Subei Basin
geothermal resources
metallogenic regularity
