天水及其南北地区温泉分布的地质—地球物理特征

根据天水及其南北地区温泉分布众多的现象,从分析地质、地球物理场着手,探讨温泉形成的区域与深部地质构造背景以及热缘机制。区内近南北向隐伏断裂发育,中酸性侵入岩、碱性玄武喷发岩构成近南北向岩浆构造带;在深部软流圈埋深变浅,岩石圈减薄、上地幔热物质上涌引起莫霍面上隆;中地壳低速、高导层同步出现;地表热流值增高,温泉呈网格状分布。该区温泉是甘肃省隆起断裂对流型地热资源有利开发地段。

The Geological and Geophysical Characteristics of Hot Spring Distribution in Tianshui and Its NS Adjacent Areas

Many hot springs distribution in Tianshui city and Its northern-southern adjacent areas.In this paper,the regional and deep geological background and the geothermal mechanism for the hot spring forming are discussed,based on its geological and geophysical fields analysis.In this region,the tectonic faults with NS direction develop,neutral-acid intrusive rocks and alkaline basalt eruptive rocks form two nearly NS direction magmatic rock belts.In the depth,the rheosphere is some shallower and leithosphere is thiner than other regions,where thermal material from upper mantle gushed up and caused Mohole uplifting.In middle crust both low velocity layer and high conduct layer appear together.On the surface,the thermal current values increase and hot springs distribute as net shape.This region is a favourable exploring region for uplift-fracture-convection type geothermal resources in Gansu province.