Lithospheric density structure study by isostatic modelling of the European geoid
- 163 Downloads
We deal with modelling of the geoid undulations for the European Plate by use of topographic and Moho data. Two models assuming linear density stratification in the lithosphere (constant contrast model CCM, constant gradient model CGM) and isostatic balance of the lithosphere were used for calculating the undulation in the flat layer approximation. The results show that the constant contrast model is able to describe the entire oceanic lithosphere, as it indicates the amplitude of thermal density change is in good agreement with the cooling plate model estimation. The constant gradient model gives reliable estimations of the lithosphere properties only in smaller regions of relatively uniform conditions like the Interior of the East European Craton. For continental and oceanic regions the resulting values of the density gradient have some average meaning and they are in interpretable correspondence with characteristic mantle heat flow. In the entire area, both models show strong confusion giving not intermediate and unrealistic lithosphere characterization, which is a result of essential differences of thermal constitution, differences in average crustal density and mineral differences of the lower lithosphere, occurring between the two major tectonic provinces (oceanic and continental). The convention of equivalent linear reduction was discussed extensively and applied as an adequate method of lithosphere thickness estimation. This approach leads to thickness determination similar to other methods (seismic, petrological and thermal). The two concepts allow for the construction of LAB (transitional zone between the lithosphere and asthenosphere) depth maps from topographic and Moho data.
Keywordsgeoid modelling isostasy lithospheric density structure Moho European Plate
Unable to display preview. Download preview PDF.
- Becker J.J., Sandwell D.T., Smith W.H.F., Braud J., Binder B., Depner J., Fabre D., Factor J., Ingalls S., Kim S-H., Ladner R., Marks K., Nelson S., Pharaoh A., Sharman G., Trimmer R., von Rosenbürg J., Wallace G. and Wetherall P., 2009. Global bathymetry and elevation data at 30 arc seconds resolution: SRTM30_plus. Mar. Geodesy, 32, 355–371 (http://topex.ucsd.edu/sandwell/publications/124_MG_Becker.pdf).CrossRefGoogle Scholar
- Carlson R.L., Snow K.R. and Wilkens R.H., 1988. Density of old oceanic crust: an estimate derived from downhole logging on ODP Leg 102. In: Mazullo E.K. (Ed.), Proceedings of the Ocean Drilling Program, Scientific Results, 102. Ocean Drilling Program, College Station, TX, 63–68. DOI: 10.2973/odp.proc.sr.102.124.1988.Google Scholar
- Dawson J.B., 2008. The Gregory Rift Valley and Neogene-Recent Volcanoes of Northern Tanzania. Geol. Soc. Memoir 33. The Geological Society, London U.K.Google Scholar
- Denis C., 1989. The hydrostatic figure of the Earth. In: Teisseyre R. (Ed.), Gravity and Low Frequency Geodynamics. Physics and Evolution of the Earth’s Interior, Vol. 4. PWN-Polish Scientific Publishers, Warszawa, Poland and Elsevier, Amsterdam, The Netherlands.Google Scholar
- Dérerová J., Zeyen H., Bielik M. and Salman K., 2006. Application of integrated geophysical modeling for determination of the continental lithospheric thermal structure in the eastern Carpathians. Tectonics, 25, TC3009.Google Scholar
- Fullea J., Fernàndez M., Zeyen H. and Vergés J., 2007. A rapid method to map the crustal and lithospheric thickness using elevation, geoid anomaly and thermal analysis. Application to the Gibraltar Arc System and adjacent zones. Tectonophysics, 430, 97–117, DOI: 10.1016/j.lithos.2010.03.003.CrossRefGoogle Scholar
- Hirschmann M.M., 2000. Mantle solidus: Experimental constraints and the effects of peridotite composition. Geochem. Geophys. Geosyst., 1, DOI: 10.1029/2000GC000070.
- Kozlovskaya E., Kosarev G., Aleshin I., Riznichenko O. and Sanina I. 2008. Structure and composition of the crust and upper mantle of the Archean-Proterozoic boundary in the Fennoscandian shield obtained by joint inversion of receiver function and surface wave phase velocity of recording of the SVEKALAPKO array. Geophys. J. Int., 175, 135–152, DOI: 10.1111/j.1365-246X.2008.03876.x.CrossRefGoogle Scholar
- Levander A., Lenardic A. and Karlstrom K.E., 2006. Structure of the continental lithosphere. In: Brown M. and Rushamer T. (Eds), Evolution and Differentiation of the Continental Crust. Cambridge University Press, Cambridge U.K., 21–66.Google Scholar
- Majdanski M., Kozlovskaya E., Swieczak M. and Grad M., 2009. Interpretation of geoid anomalies in the contact zone between the East European Craton and the Palaeozoic Platform-I. Estimation of effects of density inhomogeneities in the crust on geoid undulations. Geophys. J. Int., 177, 321–333, DOI: 10.1111/j.1365-246X.2008.03954.x.CrossRefGoogle Scholar
- Parsons B. and Sclater J.G., 1977. An analysis of the variation of ocean floor bathymetry and heat flow with age. J. Geophys. Res., 82(B5), 802–827.Google Scholar
- Pavlis N.K., Holmes S.A., Kenyon S.C. and Factor J.K., 2008. An Earth Gravitational Model to degree 2160: EGM2008. Geophys. Res. Abs., 10, EGU2008-A-01891 (full version available at http://massentransporte.de/fileadmin/2kolloquium_muc/2008-10-08/Bosch/EGM2008.pdf).Google Scholar
- Puziewicz J., Czechowski L., Krysinski L., Majorowicz J., Matusiak-Malek M. and Wróblewska M., 2012. Lithosphere thermal structure at the eastern margin of the Bohemian Massif: a case petrological and geophysical study of the Niedzwiedz amphibolite massif (SW Poland). Int. J. Earth Sci., 101, 1211–1228, DOI: 10.1007/s00531-011-0714-7.CrossRefGoogle Scholar
- Stacey F.D., 1992. Physics of the Earth. Problem Solutions. 3rd Edition. Brookfield Press, Kenmore, Qld.Google Scholar
- Swieczak M., Kozlovskaya E., Majdanski M. and Grad M., 2009. Interpretation of geoid anomalies in the contact zone between the East European Craton and the Palaeozoic Platform-II: Modelling of density in the lithospheric mantle. Geophys. J. Int., 177, 334–346, DOI: 10.1111/j.1365-246X.2009.04103.x.CrossRefGoogle Scholar
- Takahashi E. and Kushiro I., 1983. Melting of dry peridotite at high pressures and basalt magma genesis. Am. Miner., 68, 859–879.Google Scholar