ESTIMATING THE DENSITY JUMP AT THE MOHOROVICIC-DISCONTINUITY FROM THECORRELATION WITH THE GEOID

For the case when the Airy type of isostatic compensation represents a n acceptable approximation of the physical reality, a simple formula i s derived, making it possible to estimate the density contrast at the Mohorovicic discontinuity (Moho) from the slope of the linear regressi on between the Moho depths and the absolute geoid undulations. Togethe r with the well-known estimates of the density jump based on the regre ssions between the Mohorovicic discontinuity and the topography resp. Bouguer gravity anomalies, this formula was applied to three geologica lly similar (young collision belts) regions at the south-western borde r of the Pannonian basin: the Dinarides, the Western Carpathians and t he Eastern Alps. It seems that the density contrast Delta rho rises fr om the south to the north through the range 0.16-0.30 gcm(-3) and that the computed mean value of 0.22 gcm(-3) might be taken as an average value for the whole Dinaric-Alpine-Carpathian area. The results point that the regression between the Mohorovicic discontinuity depths and t he absolute geoid undulations could alone suffice for the determinatio n of the density jump Delta rho at the crust-mantel boundary.