Summary
The hypothesis is developed that convection takes place continuously in the upper mantle and episodically also in the lower mantle. The reason for the latter assumption is seen in the temperature dependence of the viscosity. By radioactive heating of the lower mantle the viscosity gradually decreases until the critical Rayleigh number is achieved. The lower mantle convection initiated in this way, however, disappears after sufficient heat has been transferred to the exterior. This heat transfer becomes evident by an increase of igneous and tectonic activities in the crust.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
E. V. Artyushkov,Density differentiation on the core-mantle interface and gravity convection, Phys. Earth Planet. Int.2 (1970), 318–325.
V. V. Belousov,Ob osnovnykh zakonomernostyakh razvitiya kontinentov, Fizika Zemli, Moscow, No. 7 (1972), 67–79.
V. E. Chain,Grundprobleme der Zyklizität/Azyklizität (Kontinuum/Diskontinuum) erdgeschichtlicher Entwicklungsprozesse, Ber. deutsch. Ges. geol. Wiss. Berlin,A16 (1971).
R. Dearnley,Orogenic fold-belts and a hypothesis of earth evolution, Phys. Chem. Earth7 (1966). 1–114 (see his Fig. 1).
G. Gastil,The distribution of mineral dates in time and space, Amer. J. Sci.258 (1960), 1–35.
H. Kölbel, Zur absoluten Dauer erdgeschichtlicher Ereignisse, Ber. deutsch. Ges. geol. Wiss. BerlinA 16 (1971), 221–229.
B. J. Levin andS. V. Majeva,On the thermal history of the earth, Ann. Geofis., Roma14 (1961), 2, 145–155.
L. Lliboutry,The driving mechanism, its source of energy, and its evolution studied with a threelayer model, J. Geophys. Res.77 (1972), 3759–3770.
E. A. Lubimova,Thermal history of the earth with consideration of the variable thermal conductivity of its mantle, Geophys. J.1 (1958), 115–134.
E. N. Lyustikh,O vozmozhnosti ispolzovaniya teorii akad. O. J. Schmidta v geotektonike, Dokl. Akad. Nauk SSSR, Moscow69 (1948), 8, 1417–1419.
A. A. Pronin,Kaledonskij zikl tektonicheskoj istorii zemli. Gercinskij zikl tektonicheskoj istorii zemli (both: Nauka, Leningrad 1969).
A. E. Ringwood,Phase transformations and the constitution of the mantle, Phys. Earth Planet. Int.3 (1970), 109–155.
M. Shimada,Melting of Albite at high pressures, J. Phys. Earth, Tokyo20 (1972), 59–70.
F. Stacey,Physics of the Earth (Wiley, New York, 1969).
J. Steiner,The sequennce of geological events and the dynamics of the milky way galaxy, J. geol. Soc. Aust., Sydney14 (1967), (1), 99–131.
H. Stille,Grundfragen der vergleichenden Tektonik (Bornträger, Berlin, 1924).
D. C. Tozer,Factors determining the temperature evolution of thermally convecting Earth models, Phys. Earth Planet. Int.2 (1970), 393–398.
A. V. Vityazev,K dinamiko-statisticheskoj teorii evolyutsii zemli, Fiz. Zemli, Moscow, No. 7 (1972), 42–47.
U. Walzer,The distribution of continents and oceans and its relation to mantle convection, Gerl. Beitr. Geophysik81, (1972), 6, 471–480.
U. Walzer,A quantitative kinematic theory of convection currents in the earth's mantle, Pure appl. Geophys.105 (1973) (IV), 669–695.
U. Walzer,Discussion of the new kinematic mantle convection theory, Pure appl. Geophys.105 (1973) (IV), 696–712.
U. Walzer,Convection in a spherical shell under consideration of equations of state for the earth's mantle, Gerl. Beitr. Geophysik82 (1973), 4.
J. Weertman,The creep strength of the earth's mantle, Rev. Geophys. Space Phys.8 (1970) (1), 145–168.
V. N. Zharkov, V. P. Trubitsyn andL. V. Samsonenko,Fizika zemli i planet.-Figuri i vnutrenneye stroyeniye (Nauka, Moscow 1971).
Author information
Authors and Affiliations
Additional information
ZIPE Contribution No. 317.
Rights and permissions
About this article
Cite this article
Walzer, U. A convection mechanism for explaining episodicity of magmatism and orogeny. PAGEOPH 112, 106–117 (1974). https://doi.org/10.1007/BF00875924
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00875924