The impact of convective heat transfer on the interpretation of fission track data - numerical models and case studies

磷灰石和锆石裂变径迹数据通常用于确定沉积盆地和出土基底岩的温度历史。沉降率和剥蚀率通常使用简单的地壳古温度场假设，例如只有传导性热传输和恒定的地热梯度。如果温度场随时间变化，特别是如果对流热传输机制是重要的，这种方法可能导致关于地球动力学和景观演变的错误结论。本研究旨在定量评价热流体通过断层和节理岩体循环引起的温度变化及其对精细裂变径迹解释的意义。正演方法将流动和热输运耦合模型计算的时间-温度历史作为输入，建立裂变径迹年龄和长度分布的多动力学模型，然后与观测数据进行比较。在对岩石的水力特性以及流体的温度和体积进行了一系列参数研究之后，建模技术应用于黑森林地区的两个案例研究。

Apatite and zircon fission track data are routinely used to determine the temperature history of sedimentary basins and exhumed basement rocks. Subsidence and denudation rates are often using simple assumptions about the palaeotemperature field in the earth's crust, e.g. only conductive heat transport and constant geothermal gradients. Such an approach may lead to erroneous conclusions about the geodynamic and landscape evolution, if the temperature field had changed with time and, particularly, if convective heat transport mechanisms were important. This study aims on a quantitative assessment of the temperature change, which can result from circulation of hot fluids through faults and jointed rock masses and its implications for refined fission track interpretation. The forward modeling approach takes the time-temperature history calculated by the coupled flow and heat transport model as input for a multi-kinetic model of fission track age and legth distribution, which then can be compared to observed data. Following a number of parameter studies varying the hydraulic properties of the rock als well as the temperature and volume of the fluid, modeling techniques are applied to two case studies from the Black Forest region.