| 甘肃天水大地热流特征及热异常成因机制 |
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| 引用本文：赵欣妍,唐晓音,郭东宝,陈程.2025.甘肃天水大地热流特征及热异常成因机制[J].地球学报,46(6):1199-1209. |
| DOI：10.3975/cagsb.2025.052711 |
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| 基金项目:甘肃省有色金属地质勘查局兰州矿产勘查院项目“甘肃省天水地区地温场特征及其主控因素研究”(编号: YSJG2023-03) |
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| 中文摘要:天水地区位于甘肃省东南部, 地热资源丰富, 是甘肃省地热勘查的有利远景区。大地热流作为表征热状态的重要参数, 是评估一个地区地热资源最基本的数据。然而, 天水地区的相关研究较为薄弱, 热流数据稀少, 难以反映该区的地温场特征。为弥补这一不足, 本研究测试了天水地区不同类型岩石的热物性参数, 结合天水地区现有的莫霍面温度、深度数据以及相应的地壳分层状况, 计算了新的热流值, 绘制了大地热流等值线图, 并在此基础上讨论了大地热流分布特征及热异常成因机制。研究表明: (1)天水地区大地热流场呈现出“西南高、东北低”的空间分布趋势; (2)中—南部地区热异常的成因机制推测为: 该区域的软流圈上隆和底辟作用引起的高温物质上涌, 热物质在浅部地壳形成的低速高导层作为热源导致地表形成热异常。西部地区热异常的成因机制推测为: 青藏高原流经秦岭地区中下地壳的弱物质流经过天水西部地区, 致使该区域形成热异常。此外, 研究区内发育的断裂在空间分布上与高热流及温泉出露区有较好的一致性。西秦岭北缘深大断裂带作为主要的导热通道使深部热物质和热量运移至浅部, 同时, 块体之间通过相对剪切运动也可能会产生部分热量。 |
| 中文关键词:大地热流 岩石热导率 岩石生热率 热异常成因机制 |
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| Heat Flow Characteristics and Thermal Anomaly Genesis in Tianshui, Gansu |
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| Abstract:The Tianshui area is located in the southeast of Gansu Province. It is rich in geothermal resources and is a favorable prospective area for geothermal exploration. As a critical parameter characterizing the thermal state, terrestrial heat flow data is used for evaluating geothermal resources in a given area. However, relevant research in the Tianshui region is relatively limited, and there is a scarcity of heat flow data, making it difficult to characterize the regional geothermal field in this area. To address this deficiency, this study measured the thermal properties of different rock types in the Tianshui area. By combining the existing data on Moho temperature and depth, as well as the corresponding crustal stratification in the region, new heat flow values were calculated, and a terrestrial heat flow contour map was generated. Based on these results, the spatial distribution characteristics of terrestrial heat flow and the mechainisms behind thermal anomalies were discussed. The study revealed that the heat flow in Tianshui area exhibits a spatial distribution trend of “high in the southwest and low in the northeast”. The mechanism for thermal anomalies in the central and southern regions is hypothesized to be related to the upwelling of high-temperature materials due to the uplift of the asthenosphere and basal subduction in this region. These thermal materials form a low-velocity, high-conductivity layer in the shallow crust, which acts as a heat source, leading to the formation of thermal anomalies at the surface. The mechanism for thermal anomalies in the western region is speculated to be caused by the weak material flow from the Qinghai-Tibet Plateau that passes through the middle to lower crust of the Qinling Mountains and reaches the western Tianshui area, inducing thermal anomalies in this region. Additionally, the spatial distribution of faults in the study area shows a notable correlation with areas of high geothermal flux and hot spring outcrops. The deep fault zone along the northern margin of the western Qinling Mountains serves as a primary thermal conduction pathway, facilitating the transfer of deep heat materials and heat to the shallow crust. Furthermore, relative shear movements between blocks may also generate additional heat. |
| keywords:geothermal heat flow rock thermal conductivity rock heat production rate thermal anomaly genesis mechanisms |
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