Heat flow in the Dead Sea from the ICDP boreholes and its implication for the structure of the basin

Abstract

Numerical simulations emulating the formation of the Dead Sea Basin (DSB) infer that it could not have been formed as a pull-apart basin with a surface heat flow lower than 50mWm2. However, previous measurements determined values of 32−40mWm2. This contradiction is known as the “Dead Sea heat flow paradox”. Here we set to re-examine the “paradox” by analyzing heat flow data in boreholes drilled by the ICDP (International Continental Drilling Program) in the northern DSB. The boreholes and the extracted sediment cores offer a unique opportunity to re-measure the heat flow in the DSB and assess the “paradox”. Heat flow was determined by obtaining in situ temperature profiles from the boreholes and conducting 469 thermal conductivity measurements on the cores. The newly computed values are in agreement with those previously obtained for the DSB and fall below the threshold of 50mWm2. Different explanations proposed to justify higher heat flow seem to fail leaving the “Dead Sea heat flow paradox” unresolved. Heat flow values and the sedimentation corrections determined in this research are consistent with the Ginzburg and Ben-Avraham subsurface model for the DSB, suggesting deeper sediment filling in the southern part of the basin.