Geothermal models of various geodymanic settings

The distribution of heat flow, deep temperature, and helium isotope ratios in axial spreading zones of mid-ocean ridges and in scattered spreading zones in backarc basins are considered, as well as in active segments of transform fracture zones, intra- and pericontinental rift zones, linear and mosaic Paleozoic fold-belts, and loading and extension sedimentary basins. The heat flow in these structural elements varies widely from 15 to 1500 mW/m², and the thickness of the thermal lithosphere is correspondingly variable. The quantitatively estimated radiogenic heat generation in Paleozoic foldbelts provides 40–50% of the background heat flow. A time-dependent heat flow is characteristic of not only recent but also Late Paleozoic tectonic belts. The origin of positive and negative geothermal anomalies has been explained. Localization of hydrocarbon fields in sedimentary basins is linked to these anomalies.