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

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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.