In the axis of the Transdanubian crustal conductivity anomaly (TCA) a 15-20 km wide part of the conductor is elevated in NE-SW direction. It is indicated by both magnetotelluric soundings and by the special behaviour of the induction arrows. In about the same strip bright spots i.e. amplitude increase of the seismic reflexions are observed at the same depth range (at about 4 km). As in the area of the TCA no borehole has been deepened, the material of the TCA is a topic of discussion: graphite or/and fluid as concluded from the similar Palaezoic CA found in the Gail valley (Periadriatic line) or around the German KTB. It is supposed that in the formation of this anomaly the "remobilised" hydrothermal graphite played a role establishing the interconnected phase [WANNAMAKER 2000] as it is suspected e.g. in the case of the Southern Alps in New Zealand. Further seismic parameters are needed, e.g. Poisson ratio, velocity distributions, etc. to better approximate the real cause of the conductivity increase. An analogy is found in the lower crustal conductor and the connected high energy reflexion. The best example for the conductivity anomaly and the bright spot is illustrated by a NW profile in the eastern side of the anomaly (MK3 profile).
|Number of pages||9|
|Publication status||Published - dec. 1 2002|
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