The energetic framework of Canadian remote communities relies on fossil fuels. This has adverse environmental and energy security issues. In order to offset diesel consumption, the search for local, sustainable and carbon-free energy sources is of utmost importance. Unfortunately, in such remote regions, subsurface data to evaluate the geothermal potential is often nonexistent. This raises a key question: how to characterize geothermal resources associated to petrothermal systems based on surface data? Answering this question is the purpose of this work highlighting how outcrops can be used as deep subsurface analogues. The variability induced by laboratory methods to characterize thermophysical properties is further evaluated in the estimation of the present-day temperature at depth. The community of Kuujjuaq, Canada, is used as an example where guidelines are defined to evaluate the steady-state geotherm. Rock samples were collected and analyzed with a guarded heat flow meter and an optical scanner to determine thermal conductivity. Radiogenic elements concentration was evaluated with gamma-ray and mass spectrometry. 2D temperature models were built taking into account the regional geology and the results obtained from the different laboratory methods. A base-case temperature of 57–88 °C at 5 km is predicted below Kuujjuaq. This range is based on different methods used to evaluate both thermal conductivity and internal heat generation. The work conducted in Kuujjuaq shows that the combination of gamma-ray spectrometry and optical scanning gives lower base-case temperature predictions when compared to mass spectrometry combined with the guarded heat flow meter. Despite the nonexistence of deep temperature measurements in northern regions, the assessment of thermophysical properties from outcrops is shown to be a useful tool for a preliminary assessment of geothermal resources in remote areas facing critical energy issues.

中文翻译：

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表层岩石的热物理性质：表征偏远北部地区地热资源的工具

加拿大偏远社区充满活力的框架依赖化石燃料。这具有不利的环境和能源安全问题。为了抵消柴油的消耗，寻找本地的，可持续的和无碳的能源至关重要。不幸的是，在这样的偏远地区，评估地热潜力的地下数据通常不存在。这就提出了一个关键问题：如何根据地表数据表征与石油热系统相关的地热资源？回答这个问题是这项工作的目的，强调了露头如何用作深层地下类似物。在估计当今深部温度时，进一步评估了由实验室方法引起的表征热物理性质的变异性。加拿大Kuujjuaq社区，作为示例，其中定义了准则来评估稳态地热。收集岩石样品，并用防护式热流量计和光学扫描仪进行分析，以确定热导率。用伽马射线和质谱法评估放射源元素的浓度。建立二维温度模型时要考虑到区域地质情况以及从不同实验室方法获得的结果。在Kuujjuaq以下，预计5 km时的基本温度为57–88°C。该范围基于用于评估导热率和内部热量产生的不同方法。在Kuujjuaq进行的工作表明，与质谱法与带保护的热流量计相结合的方法相比，伽马射线能谱法和光学扫描法相结合可提供较低的基准温度预测。