Deep temperature distribution along three profiles crossing the Teisseyre-Tornquist tectonic zone in Poland

Abstract

The Teisseyre-Tornquist tectonic zone is a large deep fracture zone separating the Precambrian East European craton from the Variscan system of Central Europe. With the use of ample deep seismic sounding data, the detailed crustal temperature distribution was calculated for three profiles crossing this zone in its northern, central and southern segments. The conversion technique of transforming the reported seismic velocities (υ_p) into heat production values (A) was used together with the temperature-dependent thermal conductivity structure and the observed surface heat flow pattern. In addition to the obtained 2-D temperature distribution, this work allowed a more reliable estimate of the crustal contribution to the surface heat flow, and thus the characteristic Moho heat flow (Q_M ~ 26 mW m⁻²), to be assessed in this region. The results can also serve as an independent confirmation of the necessity of applying the υ_p−A conversion separately for Phanerozoic and for Precambrian rocks.