Granitoids: Main petrogenetic classifications in relation to origin and tectonic setting

Abstract

Comparison of the twenty most frequently used petrogenetic classifications of granitoids is summarized using petrography, nature and abundance of enclaves, mineralogy, major and trace element, and isotope geochemistry. This comparison indicates considerable agreement between most authors concerning the main divisions. Differences result either from different genetic models or from the weighting of the criteria used, such as nature of the source, relative proportions of crustal and mantle contributions, magmatic processes, and types of emplacement. In the classification proposed here, three main groups of granitoids correspond respectively to a crustal, a mantle, or a mixed (crustal and mantle) origin of the magmas. Each of these main groups is subdivided into two or three types. Distinct petrographic, mineralogical, and chemical characteristics result from differences in the origin and tectonic setting of the granitoid magmas. Consequently, granitoids with well-defined petrographic, mineralogical, chemical features and ages may provide information on the changes of tectonic settings with space, time, or both, i.e. they may be used as geotectonic tracers.

The Geology and Geochemistry of the East African Orogen in Northeastern Mozambique

“…Since the 1970s, around 20 different classification schemes have been proposed for granitoids (see review in Barbarin, 1990), but no genetic scheme has gained universal acceptance. This reflects the hidden complexity resulting from a number of processes that can generate granitic magmas, resulting in their apparently simple mineral assemblages (e.g.…”

“…The ambition of this publication is to establish the lithostratigraphic/tectonostratigraphic framework adopted in the new map of northestern Mozambique (Norconsult, 2007a;b). Hereafter, this framework, as summarized in Figure 17, is compared with the one of Pinna et al (1993).…”

Petrogenesis and Tectonic Environment of Granites, Eastern Ghats, South India- A Case Study

“…Strong correlation between the types of granites and tectonic settings have been pointed out by Streckeisen (1974); Pitcher, (1983); Patchet and Ruiz (1987); Lameyre (1988); Pupin (1988); Maniar and Piccoli (1989); Barbarin (1990); Bonin (1990);and Eby (1990). Fyfe (1988) believes that collision mechanisms or collision thickening provide a suitable mechanism in crustal melting for large granite masses with continental crust chemistry and isotope systematics.…”

The Formation Environment of K-feldspar Porphyritic Granite from E-Mount, Yunnan

“…The petrographic, mineralogical, and chemical characteristics, such as initial εNd (t)= -6.52~-8.43, T 2DM model ages 2.01~2.19Ga, weighted average 2.1Ga [1], resulting from granitic magmas in E-Mount Pluton is subdivided into KCG type [6], suggesting that nature of the source is main correspond to crustal origin of the magmas at the age of 2.1Ga. overlapping areas of them, suggesting that these magmas may derive from hybrid magmas, formed by reaction of basaltic melts with metagreywacke of supracrustal origin.…”