Cretaceous granites-possible source of the Carpathian gravity low

Abstract

The Carpathian gravity low is one of the most discussed geophysical problems in the area of the Western Carpathians. The source of this regional anomaly has been debated since the 1980s. The ideas of individual authors were based on the powerful sedimentary layers in the bedrock of the flysch and Central Western Carpathians or on the effect of the source at the level of the Moho discontinuity. In 1980, the first interpretation appeared, when the authors connected the source with the presence of granitoid masses. In the course of time, individual unrealistic ideas about the influence of molassoid sediments or deep structures were gradually excluded. The work provides new interpretations based on integrated seismic, magnetotelluric (MT), and gravity data, and its conclusions are supported by the presented data and models - with limited quantitative uncertainty analysis. The study advances understanding of the Western Carpathians' crustal structure and offers a plausible geological explanation that refines long-debated hypotheses about the gravity anomaly. The results gained on the bases of the reinterpretation of gravity, magnetic, reflection seismic and magnetotelluric data (MT) confirmed the existence of an environment that can be explained by the presence of granites based on the absence of significant reflexes and the presence of high-resistivity horizons in the Low Tatras area. In this paper, compared to other similar works, a model is presented that assumes the presence of Cretaceous granitoid complexes. It is based on a comparison with a similar gravity effect manifested in the Rochovce area. Cretaceous granites drilled here proved the presence of such complexes in the subsoil in the Tatric and Veporic units. From paleographic studies, it is possible to find a connection with similar bodies of Cretaceous granites (banatites) located in the range from the Apusena Mountains to the South Carpathians.