Mantle geodynamics

Zindler A, Hart SR (1986) Chemical geodynamics. Aim Rev Earth Planet Sci 14 493-571 Zindler A, Standigel H, Batiza R (1984) Isotope and trace element geochemistry of young Pacific seamounts implications for the scale of upper mantle heterogeneity. Earth Planet Sci Lett 70 175-190... 

This is a problem of considerable geodynamic and petrological impact on the mantle scale, molecular processes are negligible (Hofmann and Hart, 1978) and elements can... 

There is a general agreement that the magmatism from the internal zones of Apennines has been generated in anomalous mantle sources, which have been affected by metasomatic enrichment in incompatible elements. However, the nature and timing of mantle metasomatic processes are still debated. This issue has paramount geodynamic implications and applies to all ultrapotassic magmatic provinces in Italy. 

The age of mantle contamination in central Italy is a key issue for geodynamic interpretation. Some authors (e.g. Castorina et al. 2000) suggest that contamination by material with high Rb/Sr and low Sm/Nd took place... 

The hypothesis for the occurrence of two distinct types of metasomatic events in a restricted area has important geodynamic implications. It has been suggested that the metasomatic modifications of the upper mantle beneath the Roman Province was produced by upper crustal material from the... 

The continuous compositional variation from Pietre Nere and Vulture to Campania and Pontine Islands supports the idea that the upper mantle beneath this transect is a hybrid between OIB-type and subduction-type material, with variable proportions between these two end-members. The origin of these components has important bearing on geodynamic significance of magmatism along the Vulture-Pontine Islands transect. 

Alternative hypotheses about the geodynamic evolution of the Tyrrhenian basin advocate convective movements of the modified upper mantle... 

De Astis G, Peccerillo A, Kempton PD, La Volpe L, Wu TW (2000) Transition from calc-alkaline to potassium-rich magmatism in subduction environments geochemical and Sr, Nd, Pb isotopic constraints from the island of Vulcano (Aeolian arc). Contrib Mineral Petrol 139 684-703 De Astis G, Kempton PD, Peccerillo A, Wu TW (2005) Geochemical and Sr-Nd-Pb isotope composition of Vulture and Campanian Province volcanics (southern Italy) implications for mantle evolution and geodynamics. Submitted for publication... 

Saltzer R. L. and Humphreys E. D. (1997) Upper mantle P wave velocity structure of the eastern Snake River Plain and its relationship to geodynamic models of the region. 

Menzies M. and Chazot G. (1985) Fluid processes in diamond to spinel facies shallow mantle. J. Geodynam. 20, 387-415. 

Wyllie P. J. (1995) Experimental petrology of upper mantle materials, processes and products. J. Geodynam. 20, 429-468. 

Allegre C. J., Othman D. B., Polve M., and Richard P. (1979) The Nd-Sr isotopic correlation in mantle materials and geodynamic consequences. Phys. Earth Planet. Inter. 19, 293-306. 

PecceriUo A. (1999) Multiple mantle metasomatism in central-southern Italy geochemical effects, timing and geodynamic imphcations. Geology 27, 315—318. 

Tardy M., Lapierre H., Struik L. C., Bosch D., and Brunet P. (2001) The influence of mantle plume in the genesis of the Cache Creek oceanic igneous rocks implications for the geodynamic evolution of the inner accreted terranes of the Canadian Cordillera. Can. J. Earth Sci. 38, 515-534. 

Nevertheless, this hypothesis has been unpopular since the 1980s, because geodynamic models, incorporating either constant mantle viscosity or a rigid upper plate of prescribed thickness, predicted that solidus temperatures could not be reached in basalt or sediment at the top of the subducting plate, except under unusual circumstances (see reviews in Kelemen et al., 2003a Peacock, 1996, 2003 Peacock et al., 1994). For example (Filer et al., 2000, p. 247), discounted their successful model involving H20-rich silicate melt because [the] successful melt-fluxed [model]. .. require[ s]... temperatures... that are... not obviously compatible with...thermal models... (Peacock, 1996). ... 

In summary, for a variety of reasons, it is unwarranted to use geodynamical models to rule out partial melting of eclogite facies sediment, basalt, or lower crustal gabbro beneath arcs. Meanwhile, we believe that geochemical data on primitive arc lavas are best understood if a partial melt of subducted sediment and/or basalt (and/or gabbro) is the primary medium for transport of in compatible trace elements into the mantle wedge. 

Nicolas, A. Christensen, N. 1.1987. Formation of anisotropy in upper mantle peridotites - a review. In Fuchs, K. Froidevaux, C. (eds) Composition, Structure and Dynamics of the Lithosphere-Asthenosphere System. Geodynamics Series, American Geophysical Union, 16,111-123. 

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