Heat flow in the Eurasian, North American and Atlantic regions

Abstract

The article is a presentation of the research results of the next stage of complex geophysical control of models of deep processes in the tectonosphere of continents and oceans, built by geological theory. Models of the crust and upper mantle are located along a system of profiles encircling the northern hemisphere of the Earth, which have are DSS sections (in some places fragmentary, especially in the oceans). In the first stage, control was performed for density models. It is shown that the gravitational field can always be explained without fitting by calculated effects with discrepancies corresponding to the errors. The second stage focused on thermal models, the effects of which were compared with the observed heat flow (HF) distribution through the surface. Solving the problem is complicated by many features of the manifestation of a nonstationary thermal field. Some of them can be considered as nearsurface interference that needs to be eliminated (but usually this is not done). The work done covered the regions of Eurasia and North America, the Atlantic Ocean, a peripheral fragment of the Pacific Ocean, and transition zones between continents and oceans. Activated and nonactivated platforms, Phanerozoic geosynclines, and rifts were studied on the continents. In transition zones, there are depressions with recent oceanisation, island arcs, and deep9sea trenches. In the oceans, there are basins and the mid9ocean ridge (MOR). In the MOR and some other areas of the World Ocean, the intensity of interference does not allow the use of observed HF for routine monitoring. In other regions, the result was achieved, although often after smoothing out the heat flow field. On the continents, the cases are better, although there are also situations where significant parts of the profiles should simply be excluded from consideration due to an unacceptable level of error. However, here it was possible to confidently demonstrate the correspondence of thermal models of deep processes to experimental HF within the limits of observation and calculation errors.