西宁盆地北西缘地下热水分布特征

Distribution characteristics of geothermal water on the northwestern margin of the Xining basin

笔者重点对西宁盆地北西缘南门峡-台子地区地下热水的赋存条件、热储构造概念模型进行了讨论。基于实际资料,得出地处老爷山凸起与双树凹陷间斜坡带,具有“凹中凸”地质结构的南门峡-台子地热异常热储为新元古界克素尔组大理岩和白垩系民和组砂砾岩,地热地质条件好。提出了该区的热储概念模型是“层控热储-侧向径流补给-大地热流供热-深大断裂导热-低热导率岩层聚热”,且具一定的地热资源开发利用前景。

The paper mainly discusses the conditions of occurrence of geothermal water and conceptual model of geothermal reservoir structure in the Nanmenxia-Taizi area, Huzhu County, on the northwestern margin of the Xining basin.The conceptual model of the geothermal reservoir proposed in the paper is as follows：stratigraphic control on the geothermal reservoir-lateral runoff recharge of groundwater-terretrial heat supply-terretrial heat conduction along the deep fault-heat storage in low-thermal conductivity rocks. On that basis, it is concluded that： this geothermal reservoir occurs in marble of the the Neoproterozoic Kesur Formation and sandy conglomerate of the Lower Cretaceous Minhe Formation, hes on a slope zone between the Laoyeshan uplift and Shuangshu depression, shows a geological structure of an ＂uplift in a depression＂, and has good geothermal-geological conditions and certain prospects of geothermal resource exploitation and utilization.