Asthenospheric structure beneath a Neogene basin in southeast Hungary

被引：61

作者：

Posgay, K ^{[1
]}

Bodoky, T ^{[1
]}

Hegedus, E ^{[1
]}

Kovacsvolgyi, S ^{[1
]}

Lenkey, L ^{[1
]}

Szafian, P ^{[1
]}

Takacs, E ^{[1
]}

Timar, Z ^{[1
]}

Varga, G ^{[1
]}

机构：

[1] EOTVOS LORAND UNIV, H-1083 BUDAPEST, HUNGARY

来源：

TECTONOPHYSICS | 1995年 / 252卷 / 1-4期

关键词：

D O I：

10.1016/0040-1951(95)00098-4

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

Beneath one of the subbasins. of the Pannonian basin formed between the Alps, Carpathians and Dinarides - the Bekes basin in southeast Hungary - a typical structure of the lithosphere and an upwelling of the asthenosphere can be inferred from seismic reflection, geothermal, geomagnetic, gravity and magnetotelluric investigations. In the Bekes basin the thickness of Neogene sediments reaches 6-7 km, i.e. the basement of the Neogene basin sinks 3-4 km over the basin area. In the reflection section of the Pannonian Geotraverse that ends in the Bekes basin the crust-mantle boundary rises by 5-6 km up to a depth of 22 km. In the course of performing and processing seismic reflection measurements particular care was given to the preservation of low-frequency (2-10 Hz) information. This explains that data were successfully received even from the upper mantle. Amplitude distribution of reflection arrivals and the dipping of reflecting surfaces permit to infer an uplift by 15-20 km in the lithosphere-asthenosphere boundary which thus is assumed to be at a depth of 40-45 km beneath the Bekes basin. In geothermal investigations the model was established with seismic results being accounted for, assuming an upwelling in the lithosphere-asthenosphere boundary. The superficial heat flow density corrected for the cooling effect of sediments was in good agreement with the values of model calculations. The latest magnetotelluric results support the upwelling position of the lithosphere-asthenosphere boundary. The geomagnetic anomaly determined over the area of the Bekes basin can be explained by the uplifted position of the lower crust. The gravity anomaly can be attributed to the combined effect of this and the upwelling in the crust-mantle boundary. It is hoped that the integrated interpretation of results obtained by various geophysical methods confirms the assumption that said methods permit to investigate the structure of the whole lithosphere and thus the disclosed results may contribute to the completion and precision of basin models studied so far.

引用

页码：467 / 484

页数：18

共 40 条

[1]

Adam A., 1990, Acta Geodaetica, Geophysica et Montanistica Hungarica, V25, P291

[2] MAGNETOTELLURIC APPROXIMATIONS FOR THE ASTHENOSPHERIC DEPTH BENEATH THE BEKES GRABEN, HUNGARY [J].