On the regional variations of heat flow, geotherms, and lithospheric thickness

Pollack, H.N. and Chapman, D.S., 1977. On the regional variation of heat flow, geo-therms, and lithospheric thickness. Tectonophysics, 38: 279-296. Geotherm families in which surface heat flow is the principal independent variable have been constructed for continental and oceanic lithospheres. The continental model is characterized by geotherms in which surface heat flow is in equilibrium with heat flowing into the lithosphere at its base plus heat generated by radioactive decay within the litho-sphere. The model accommodates the regional variation of the surface heat flow with pro-portional variations in the radioactivity of the surficial enriched zone and in the deeper heat flow. The proportionality is dictated by a new and general linear relationship between reduced heat flow and mean heat flow for a region (o * r 0.6 ifo), which enables both q * and the mean heat production of the enriched zone to be estimated from knowl-edge of the mean surface heat flow of a province. The oceanic model is characterized by the transient cooling of a semi-infinite medium with an initial temperature gradient and some near-surface radiogenic heat production. The model yields a heat flow in satisfac