The experimentally supported relationship between seismic velocity and radiogenic heat production was used to estimate the vertical distribution of heat sources in the lithosphere. Using these data we propose and compare geothermal models constrained by heat production (converted from seismic velocity) for ten selected extension zones in Africa, Asia, Europe and North America. Heat production in the crust sharply decreases with depth, but it can be shown that in the extension zones the vertical differentiation rate of heat sources increases in comparison with "normal" terranes. Strongly increased differentiation is also perceptible in the subcrustal lithosphere, where the rock material must have been enriched with radio-elements at the expense of deeper layers. Rifting thus represents a complex large-scale alternation of heat production in the lithosphere. The resulting distribution of radiogenic heat sources seems to be preserved during the entire life span of the rift and can be detected even in palaeorifts.
ASJC Scopus subject areas
- Earth-Surface Processes