Magnetic field of the Western Carpathians (Slovakia): reflections on the structure of the crust

Abstract

Abstract:A new digital magnetic map of Slovakia on the scale of 1: 200,000 and 1: 500,000 was compiled at the end of 2008 as the output of database magnetic objects from the whole territory of Slovakia at a scale of 1: 50,000. The variable geological structure of the West Carpathian crust is depicted in the equally variable magnetic field of this region. A sizable number of magnetic anomalies with manifold character have been recognized. The basic anomalies distribution was divided into two groups: anomalies connected with rocks of the pre-Neogene basement and anomalies which originate in Neogene and Quaternary volcanic products. Most of the significant anomalies in the pre-Neogene basement were interpreted, modelled and consequently its geological and tectonic classification was worked out. On the basis of the anomalous field features, the following sources of anomalies have been distinguished: a) known, located on the surface, or at shallow depths verified by boreholes, mainly expressed by simple morphology, b) deep-seated and expressed by complicated morphology, reinterpreted or newly interpreted and also problematic. According to our present knowledge the interpretations are insufficient and remain open for further investigation. The above mentioned sources of magnetic anomalies are classified in terms of tectonic provenience to the main tectonic units.

Geological interpretation of magnetotelluric sounding in the southern part of seismic profile 2T (Central Slovakia)

“…Its fragments are brought to surface in the form of xenoliths in basalts. This Proterozoic basement is also a source of an expressive magnetic anomaly (Kubeš et al, 2010).…”

Joint interpretation of gravity and magnetic data in the Kolárovo anomaly region by separation of sources and the inversion method of local corrections

“…The Kolárovo magnetic high (N4 anomaly in Kubeš et al 2010) coincides with the Kolárovo gravity high (Fig. 1).…”

“…Their body has its lower boundary at 18 km while its top boundary rises to depths of 5.3-6.6 km depending on the number of vertices of the modeled polygonal body. Kubeš et al (2010) interpret the Kolárovo magnetic anomaly (N4 of their map based on aeromagnetic data) by means of modeling (using the Oasis Montaj geophysical software) in terms of a basic intrusive body with its top interface at depths of 5.5 to 6 km (ibid), and so still within the bedrocks of the Tertiary sediments.…”

“…The Danube Basin displays peculiar anomalies in the gravity and magnetic fields that are supposedly associated with deep seated sources within the pre-Neogene basement (Kubeš et al 2001(Kubeš et al , 2010. According to Kubeš et al (2010) the interpretations of these sources are insufficient and problematic and thus remain open for further investigation.…”

“…According to Kubeš et al (2010) the interpretations of these sources are insufficient and problematic and thus remain open for further investigation. Here we present a new interpretation of both the Kolárovo gravity anomaly (gravity high) and the Kolárovo magnetic anomaly (anomaly "N4" in Kubeš et al 2010) by means of a 3D inversion of gravity and magnetic data based on depth-wise separation of sources and the so-called "method of local corrections". This non-linear inversion method can invert gravity or magnetic data in terms of interface (contact) surfaces or anomalous source bodies, as well as a combination of these two classes of sources.…”