Thermal evolution of sedimentary basin formation with variable thermal conductivity

• Published in: Geophysical research letters 2000-01, Vol.27 (2), p.265-268
• Main Authors: Starin, L., Yuen, D. A., Bergeron, Stephen Y.
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Geophysics: general, magnetic, electric and thermic methods and properties; Internal geophysics; Petrology of sedimentary rocks except quaternary rocks; Sedimentary rocks
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/1999GL008417

Understanding the thermal evolution of sedimentary basins is crucial for the geosciences and petroleum genesis. A recent model of thermal conductivity, based on microscopic physics, has shown that the variations of thermal conductivity depend nonlinearly on the temperature, pressure and mineralogy. The time‐dependent temperature equation takes on a nonlinear diffusive character with the temperature‐dependent portion of the thermal conductivity. We have compared the numerical solutions of the temperature fields, following a lithospheric stretching event between constant thermal conductivity and variable thermal conductivity. There is a great sensitivity of the thermal signatures to the parameter governing the influence of mineralogy on the phonon contribution to the thermal conductivity. For an olivine‐like lithosphere, differences on the order of 5% or 60 to 70K in the interior temperature between the two models can be expected. For times younger than 150 Myr, the topography for the variable conductivity model is shallower by around 5 to 10% than for the constant conductivity model, while the surface heat flow remains always lower for variable conductivity and the departure between the two conductivity models can reach 20% in the early stage. Variable thermal conductivity may play a non‐trivial role in thermal‐chemical reactive processes under basins.