Figure 7. A. Variations in heat flow with stretching factor beta for a pure-shear model (McKenzie, 1978) including the effects of radiogenic heating (Voorhoeve and Houseman, 1988). Separate curves are for separate lithospheric ages as indicated (in Ma), with expected values for the 130-Ma Iberia Margin falling within the shaded region. Assumed values of radiogenic heat production (H) and thickness (h) are 3 W/m3 and 15 km, respectively. After Louden et al. (1991). B. Values of corrected heat flow (for Iberia Basin sites as a function of stretching factor (), compared to pure-shear models with various amount of radiogenic heat production (H in W/m3), as indicated. Lithospheric age is 130 Ma; other parameters in the model are the same as used in (A). Open symbols and dotted error bars indicate values with significant nonlinearities in temperature gradient for Galicia Bank.

Figure 7. A. Variations in heat flow with stretching factor (

) for a pure-shear model (McKenzie, 1978) including the effects of radiogenic heating (Voorhoeve and Houseman, 1988). Separate curves are for separate lithospheric ages as indicated (in Ma), with expected values for the 130-Ma Iberia Margin falling within the shaded region. Assumed values of radiogenic heat production (H) and thickness (h) are 3 µW/m³ and 15 km, respectively. After Louden et al. (1991). B. Values of corrected heat flow (

) across Galicia Bank and for Iberia Basin sites as a function of stretching factor (

), compared to pure-shear models with various amount of radiogenic heat production (H in µW/m³), as indicated. Lithospheric age is 130 Ma; other parameters in the model are the same as used in (A). Open symbols and dotted error bars indicate values with significant nonlinearities in temperature gradient for Galicia Bank.