Archaean greenstone belt

Thus, U/Pb ratios are not generally fractionated significantly by the crust formation processes widely invoked in the generation of Archaean greenstone belts and the TTG suites... 

PoLAT, A. Kerrick, R. 2000. Archaean greenstone belt magmatism and the continental growth-mantle evolution connection constraints from the Th-U-Nb-LREE systematics of the 2.7 Ga Wawa subprovinee, Superior Province, Canada. Earth and Planetary Science Letters, 175, 41-54. 

Wilson, A. H. Carlson, R. W. 1989. A Sm-Nd and Pb isotope study of Archaean greenstone belts in the southern Kaapvaal craton. South Africa. Earth and Planetary Science Letters, 96, 89-105. 

S. Chile a model for Archaean greenstone belt formation. / Windley, B. F. (ed.) The Early History of the Earth. Wiley, New York, 131-146. 

Bickle, M. J., Nisbet, E. G. Martin, A. 1994. Archaean greenstone belts are not oceanic crust. Journal of Geology, 102, 121-138. 

Silva, K. E. 1997. Komatiites from the Belingwe greenstone belt, Zimbabwe constraints on the development of Archaean greenstone belts. PhD thesis. University of London. 

Of these, late Archaean sedimentary basins are the most "modern" in their form and can be clearly recognized as upper crust. Similarly, the relatively low metamorphic grade of many Archaean greenstone belts indicates that they too represent upper Archaean crust. In contrast, Archaean granite-gneiss terrains more commonly belong to the deeper continental crust and variously represent middle to lower continental crust. There are only a few places... 

Archaean Cratons contain three different types of lithological association, each of which provides important information about the early stages of the Earth System. These associations are Archaean greenstone belts, late Archaean sedimentary basins, and Archaean granite-gneiss terrains. We will consider each in turn. 

TABLE 1.4 Key lithological associations recognized in Archaean greenstone belts (modified from Eriksson et ah, 1994). ... 

Basaltic rocks are common in Archaean terrains and are particularly abundant in Archaean greenstone belts. However, they are frequently altered and metamorphosed, and only the best preserved samples should be used to obtain information about the composition of the Archaean mantle. Recent research has shown that Archaean greenstone belts formed in a number of different tectonic environments (see Chapter 1, Section 1.3.1). This means that greenstone belt basalts potentially offer an insight into a variety of mantle environments in the early Earth. 

Dirks, P.H.G.M., Jelsma, H.A., and Hofmann, A., 2002. Thrust-related accretion of an Archaean greenstone belt in the Midlands of Zimbabwe. f. Struct. Geol., 24, 1707-27. 

Eriksson, K.A., Krapez, B., and Fralick, P.W., 1994. Sedimentology of Archaean greenstone belts signatures of tectonic evolution. Earth Sci. Rev., 37, 1-88. 

Veizer, J., Hoefs, J., Lowe, D.R., and Thurston, P.C., 1989. Geochemistry of Precambrian carbonates II. Archaean greenstone belts and Archaean sea water. Geochim. Cosmochim. Acta, 53, 859-71. 

Rollinson H.R., 1933, The geochemistry of mafic and ultiainafic rocks from the Archaean greenstone belts of Sierra Leone. Mineral. Mag., 47, 267—280. 

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