Plateau Uplift pp 352-363 | Cite as

Relation of Geophysical and Petrological Models of Upper Mantle Structure of the Rhenish Massif

  • K. Fuchs
  • K. H. Wedepohl
Conference paper


The multi-disciplinary investigations of the plateau uplift of the Rhenish Massif provided an excellent opportunity to compare geophysical and petrological models of structure, composition and dynamics of the upper mantle. A low-velocity volume immediately below the crust-mantle boundary is observed east of the river Rhine whereas an absence of a sharp Moho is characteristic for the area west of this river. A low-velocity volume at 50 to 150 km depth in the Westeifel region is explained by the presence of 1% partial melt. This abnormal mantle could have caused 200–300 m uplift. The occurrence of anisotropy of P-velocities in the upper mantle can be correlated with depleted mantle compositions observed in peridotite xenoliths. The abundant depleted spinel-peridotite xenoliths sampled from Tertiary and Quaternary alkalic basalts in the Eifel, Westerwald, Hessian Depression areas contain on average about 70% olivine. These lherzolites and harzburgites cannot ex-plain the chemical composition of nepheline bearing basalts except by assuming very low degrees of partial melting of the former rocks (≤1%). A few percent (or less) partial melt in peridotites has a very low flow velocity in the porous space of peridotite and probably cannot form magma reservoirs of reasonable size in the upper mantle to feed volcanism. But a small proportion of immobile partial melt can explain low velocity volumes in the upper mantle without effecting the density in the area of the Rhenish Massif significantly. The cooling and solidification of this anomalous mantle needs time in excess of 10 m. y. Peridotite xenoliths are mainly equilibrated in the range from 900° to 1150°C related to a depth range from 60 to 80 km. Coarse grained xenoliths without recrystallization after heavy shearing are abundant in the Hessian Depression whereas porphyroclastic peridotites predominate in the volcanic areas of the Rhenish Massif. The latter probably indicate shearing in the border zones of uprising diapirs in the upper mantle. Metasomatically altered peridotites (with about 4% amphibole or phlogopite) occur as xenoliths in basalts from the sampled areas. They are probably the source rocks for the magmas of the nepheline containing basalts. Geothermal conditions as derived from petrological models for the upper mantle outside the Rhenish Massif have been presented in a tentative profile.


Partial Melting Mantle Xenolith Mantle Rock Garnet Peridotite Peridotite Xenolith 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Ahorner, L., 1970. Seismo-tectonic relations between the Graben zones of the upper and lower Rhine valley. In: lilies, J.H., Müller, St. (eds.) Graben Problems. Schweizerbart, Stuttgart, pp 155–166.Google Scholar
  2. Ahrens, L.H., Dawson, J.B., Duncan, A.R. and Erlank, A.J. (eds.), 1975. Physics and chemistry of the earth, Vol. 9. Pergamon Press, Oxford, New York, 940 pp.Google Scholar
  3. Allègre, C.J. and Minster, J.F., 1978. Quantitative models of trace element behavior in magmatic processes. Earth Planet. Sci. Lett., 38: 1–25.Google Scholar
  4. Ansorge, J., Bonjer, K.-P., and Emter, D., 1979. Structure of the uppermost mantle from long-range seismic observations in Southern Germany and the Rhinegraben area. Tectonophysics, 56: 31–48.CrossRefGoogle Scholar
  5. Backhaus, E., Gramann, F., Kaever, M., Lepper, J., Lohmann, H.H., Meiburg, P., Preuss, H., Rambow, D., and Ritzkowski, S., 1980. Erläuterungen zur Geologischen Karte des Reinhardswaldes 1:50 000. Hess. Landesamt Bodenforsch., Wiesbaden, 32 pp.Google Scholar
  6. Bamford, D., 1973. Refraction data in Western Germany - a time-term interpretation. Z. Geophys., 39: 907–927.Google Scholar
  7. Birch, F., 1958. Interpretation of seismic structure of the crust in the light of experimental studies of wave velocities in rocks. Contrib. Geophys. 6: 158–170.Google Scholar
  8. Boyd, F.R. and McCallister, R.H., 1976. Densities of fertile and sterile garnet peridotites. Geophys. Res. Lett., 3: 509–512.Google Scholar
  9. Boyd, F.R. and Meyer, H.O.A. (eds.), 1979. The mantle sample: inclusions in kimberlites and other volcanics. Proc. 2nd Int. Kimberl. Conf. Vol. 2, Am. Geophys. Union, Washington D.C., 424 pp.Google Scholar
  10. Den Tex, E., 1982. Dynamothermal metamorphism across the continental crust/mantle interface. Fortschr. Miner., 60: 57–80.Google Scholar
  11. Drisler, J. and Jacoby, 1983. Gravity anomaly and density distribution of the Rhenish Massif. This Vol.Google Scholar
  12. Fuchs, K., 1983. Recently formed elastic anisotropy and petrological models for the continental subcrustal lithosphere in Southern Germany. Phys. Earth Planet. Inter., 31: 93–118.Google Scholar
  13. Gerke, K., 1957. Die Karte der Bouguer-Isanomalen 1:1000000 von Westdeutschland. Dtsch. Geodät. Kommiss., Reihe B, Heft 46: Teil I, Frankfurt a.M., 13 pp.Google Scholar
  14. Green, D.H. and Liebermann, R.C., 1976. Phase equilibria and elastic properties of a pyrolite model for the oceanic upper mantle. Tectonophysics, 32: 61–82.CrossRefGoogle Scholar
  15. Haenel, R., 1983. Geothermal investigations in the Rheniäh Massif. This Vol.Google Scholar
  16. Hofmann, A.W. and Hart, S.R., 1978. An assessment of local and regional isotopic equilibrium in the mantle. Earth Planet. Sci. Lett., 38: 44–62.Google Scholar
  17. Huckenholz, H.G. and Noussinanos, Th., 1977. Evaluation of temperature and pressure conditions in alkali-basalts and their peridotite xenoliths in NE Bavaria, Western Germany. Neues Jahrb. Mineral. Abh., 129, 2: 139–159.Google Scholar
  18. Huckenholz, H.-G. and Schröder, B., 1981. Die Alkalibasaltassoziation der Heldburger Gangschar (Exkursion I am 25. April 1981. Jahresber. Mitt. Oberrhein. Geol. Ver., N.F., 63: 97–110.Google Scholar
  19. Hutchison, R., Chambers, A.L., Paul, D.K., and Harris, P.G., 1975. Chemical variation among French ultramafic xenoliths - evidence for a heterogeneous upper mantle. Miner. Mag., 40: 153–170.Google Scholar
  20. Jaques, A.L. and Green, D.H., 1980. Anhydrous melting of peridotite at 0–15 kb pressure and the genesis of tholeiitic basalts. Contrib. Mineral. Petrol., 73: 287–310.Google Scholar
  21. Jödicke, H., Untiedt, J., Olgemann, W., Schulte, L., and Wagenitz, V., 1983. Electrical conductivity structure of the crust and upper mantle beneath the Rhenish Massif. This Vol.Google Scholar
  22. Lachenbruch, A.H., Sass, J.H., Munroe, R.J., and Moses, Jr., T.H., 1976. Geothermal setting and simple heat conduction models for the Long Valley Caldera. J. Geophys. Res., 81: 769–784.Google Scholar
  23. Leven, J.H., Jackson, I., and Ringwood, A.E., 1981. Upper mantle seismic anisotropy and lithospheric decoupling. Nature (London), 289: 234–239.CrossRefGoogle Scholar
  24. Lippolt, H.J., 1983. Distribution of volcanic activity in space and time. This Vol.Google Scholar
  25. Lloyd, F.E. and Bailey, D.K., 1975. Light element metasomatism of the continental mantle: the evidence and the consequences. Phys. Chem. Earth, 9: 389–416.Google Scholar
  26. Mechie, J., Prodehl, C., and Fuchs, K., 1983. The long-range seismic experiment in the Rhenish Massif. This Vol.Google Scholar
  27. Mengel, K., 1981. Petrographische und geochemische Untersuchungen an Tuffen des Habichtswaldes und seiner Umgebung und an deren Einschlüssen aus der tieferen Kruste und dem oberen Mantel. Dissertation, Univ. Göttingen, 104 pp.Google Scholar
  28. Mengel, K. and Wedepohl, K.H., 1983. Crustal xenoliths in Tertiary volcanics from the northern Hessian Depression. This Vol.Google Scholar
  29. Mercier, J.C.C. and Nicolas, A., 1975. Textures and fabrics of upper mantle peridotites as illustrated by xenoliths from basalts. J. Petrol., 16: 454–487.Google Scholar
  30. Modreski, P.J. and Boettcher, A.L., 1973. Phase relations of phlogopite in the system K2O-MgO-CaO-Al2O3-SiO2-H2O to 35 kbars: a better model for micas in the interior of the earth. Am. J. Sci., 273: 385–415.Google Scholar
  31. Oehm, J., 1980. Untersuchungen zu Equi- librierungsbedingungen von Spinell-Peridotit-Einschlüssen aus Basalten der Hessischen Senke. Dissertation, Univ. Göttingen, 78 pp.Google Scholar
  32. O’Neill, H.St.C., 1981. The transition between spinel lherzolite and garnet lherzolite and its use as a geobarometer. Contrib. Mineral. Petrol., 77: 185–194.Google Scholar
  33. Pollack, H.N. and Chapman, D.S., 1977. On the regional variation of heat flow, geotherms and lithospheric thickness. Tectonophysics, 38: 279–296.CrossRefGoogle Scholar
  34. Raikes, S., 1980. Teleseismic evidence for velocity heterogeneity beneath the Rhenish Massif. J. Geophys., 48: 80–83.Google Scholar
  35. Raikes, S. and Bonjer, K.-P., 1983. Large-scale mantle heterogeneities beneath the Rhenish Massif and its vicinity from teleseismic P-residual measurements. This Vol.Google Scholar
  36. Ringwood, A.E., 1975. Composition and petrology of the Earth’s mantle. McGraw-Hill, New York, 618 pp.Google Scholar
  37. Roedder, E., 1965. Liquid CO2 inclusions in olivine bearing nodules and phenocrysts from basalts. Am. Mineral., 50: 1746–1782.Google Scholar
  38. Sachtleben, T., 1980. Petrologie ultrabasischer Auswürflinge aus der Westeifel. Dissertation, Univ. Köln, 160 pp.Google Scholar
  39. Scarfe, C.M., Takahashi, E., and Yoder, H.S., 1980. Rates of dissolution of upper mantle minerals in alkali olivine basalt melt at high pressures. Carnegie Inst. Washington, Yearb., 79: 290–296.Google Scholar
  40. Seek, H.A. and Reese, D., 1979. Ent-stehung und Zusammensetzung von Gläsern in Peridotiten der Westeifel. Fortschr. Mineral., 57, 1: 224–225.Google Scholar
  41. Seck, H.A. and Wedepohl, K.H., 1983. Mantle xenoliths from the Tertiary and Quaternary volcanics of the Rhenish Massif and the Tertiary basalts of the northern Hessian Depression. This Vol.Google Scholar
  42. Spera, F.J., 1980. Aspects of magma transport. In: Hargraves, R.B. (ed.) Physics of magmatic processes. Princeton Univ. Press, Princeton N.J., 585 pp.Google Scholar
  43. Spera, F.J., 1981. Carbon dioxide in igneous petrogenesis: II Fluid dynamics of mantle metasomatism. Contrib. Mineral. Petrol., 77: 56–65.Google Scholar
  44. Stosch, H.-G., 1980. Zur Geochemie der ultrabasaltischen Auswürflinge des Dreiser Weihers in der Westeifel: Hinweise auf die Evolution des kontinentalen oberen Mantels. Ph.D. thesis, Univ. Köln, 233 pp.Google Scholar
  45. Stosch, H.G. and Seck, H.A., 1980. Geochemistry and mineralogy of two-spinel peridotite suites from Dreiser Weiher, West Germany. Geochim. Cosmochim. Acta, 44: 457–470.Google Scholar
  46. Stosch, H.G., Carlson, R.W., and Lugmair, G.W., 1980. Episodic mantle differentiation: Nd and Sr isotopic evidence. Earth Planet. Sci. Lett., 47: 263–271.Google Scholar
  47. Voll, G., 1983. Crustal xenoliths and their evidence for crustal structure underneath the Eifel volcanic district. This Vol.Google Scholar
  48. Wedepohl, K.H. and Ritzkowski, S., 1980. Die nördliche Hessische Senke. Fortschr. Mineral., 58, 2: 4 - 31.Google Scholar
  49. Wedepohl, K.H., Mengel, K., and Oehm, J., 1983. Depleted mantle rocks and metasomatically altered peridotite inclusions in Tertiary basalts from the Hessian Depression (NW Germany). Proc. 3rd Int. Kimberl. Conf. Terra Cognita (in press).Google Scholar
  50. Wells, R.A., 1977. Pyroxene thermometry in simple and complex systems. Contrib. Mineral. Petrol., 62: 129–139.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1983

Authors and Affiliations

  • K. Fuchs
    • 1
  • K. H. Wedepohl
    • 2
  1. 1.Geophysikalisches InstitutUniversität KarlsruheKarlsruhe 21Fed. Rep. of Germany
  2. 2.Geochemisches InstitutUniversität GöttingenGöttingenFed. Rep. of Germany

Personalised recommendations