Silicic Magmatism

Silicic volcanics occur as lavas at San Vincenzo, Roccastrada, Monte A-miata, Monti Cimini and Tolfa-Manziana-Cerite complex. Pyroclastic rocks are scarce or absent, and a few ignimbrites only occur at Monti Cimini and Cerite complex. Silicic intrusions crop out in the islands of Elba, Montecristo and Giglio, and at Campiglia and Gavorrano in southern Tuscany. Other granitoid bodies occur as seamounts in the northern Tyrrhenian Sea (e.g. Vercelli Barbieri et al. 1986) and as hidden intrusions in several places of southern Tuscany (e.g. Franceschini et al. 2000 Poli et al. 2003). 

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Twist D. and Harmer R.E.J., 1987, Geochemistry of contrasting siliceous magmatic suites in die Bush veld Complex genetic aspects and implicadons for tectonic discriminadon diagrams, f. Vole. Geothermal Ees., 32,. 83-98. 

As the rock cycle continues, the calcium silicate minerals are eventually uplifted onto land where they imdergo chemical weathering. This reaction involves acid hydrolysis driven by carbonic acid. The latter is derived from the dissolution of the magmatic CO2 in rainwater ... 

Ghiorso M. S., Carmichael I. S. E., Rivers M. L., and Sack R. O. (1983). The Gibbs free energy of mixing of natural silicate liquids an expanded regular solution approximation for the calculation of magmatic intensive variables. Contrib. Mineral Petrol, 84 107-145. 

Ottonello G. (1983). Trace elements as monitors of magmatic processes (1) limits imposed by Henry s law problem and (2) Compositional effect of silicate liquid. In The Significance of Trace Elements in Solving Petrogenetic Problems and Controversies, S. Augusthitis, ed. Theophrastus Publications, Athens. 

Nickel ores are of two general types magmatic sulfide ores, which are mined underground, and lateritic hydrous nickel silicates or gamierites, which are surface mined (Duke 1980a Warner 1984). 

Ghiorso M.S. (1987a) Chemical mass transfer in magmatic processes, III crystal growth, chemical diffusion and thermal diffusion in multicomponent silicate melts. Contrib. Mineral. Petrol. 96, 291-313. 

Hofmann A.W. (1980) Diffusion in natural silicate melts a critical review. In Physics of Magmatic Processes (ed. R.B. Hargraves), pp. 385-417. Princeton, NJ Princeton University Press. 

Fig. 3. SEM backscattered electron image of alteration in zirconolite from the Afrikanda alkaline complex, Kola Peninsula, Russia. This crystal exhibits complex magmatic zoning, late-stage replacement by an unknown Ba-Zr-Ti-silicate phase, and preferential alteration along cracks and Th-U-rich zones.

Perovskites also exhibit reaction relationships with phosphate minerals and exotic alkali-titanium-silicate minerals under late-stage magmatic conditions. In a systematic study of loparite mineral chemistry in the Lovozero alkaline complex, Russia, Kogarko et al. (2002) have... 

Shaw, H. R. 1972. Viscosities of magmatic silicate liquids an empirical method of prediction. American Journal of Science, 272, 870-893. 

Magmatic achondrites - crystallized from silicate magma Aubrites... 

The LAB-IIICD irons are non-magmatic irons that often contain silicate inclusions. Tungsten is significantly more radiogenic in these meteorites than in the IIAB irons because... 

Noble, D.C., Ressel, M.W. and Connors, K.A. (1998) Magmatic As, Sb, Cs and other volatile elements in glassy silicic rocks. Abstracts with Programs. The Geological Society of America, 30(7), 377. 

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