Articles Scientifiques

Dernier ajout : 30 septembre 2009.

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Derniers articles

Multi-batch, incrémental assembly of a dynamic magma chamber : the case of the Peninsula pluton granite (Cape Granite Suite, South Africa)

Mineralogy and Petrology, 2012

Mardi 18 décembre 2012, par Arnau // Articles Scientifiques

The S-type Peninsula Pluton (South Africa) exhibits substantial compositional variability and hosts a large variety of mafic and felsic magmatic enclaves with contrasting textures and compositions. Moreover, the pluton is characterized by mechanical concentrations of K-feldspar megacrysts, cordierite and biotite, generating a complex array of magmatic structures including schlieren, pipes, and spectacular sheeted structures. Chemical evidence indicates that the pluton is constructed (...) Lire la suite »

Isotopic variations in S-type granites : an inheritance from a heterogeneous source.

Contributions to mineralogy and petrology, 2012

Samedi 9 juillet 2011, par Arnau // Articles Scientifiques

Inherited zircons from S-type granites provide exceptionally good insight into the isotopic heterogeneity of their sources. Zircons from four samples (one granite, two granodiorites, one granodioritic enclave) of Pan-African S-type granite of the Cape Granite Suite (c. 540 Ma) have been the subject of a laser LA-ICP-MS zircon U/Pb study to determine emplacement ages and inheritance. Zircons from three of these samples (2 granodiorites and 1 granodioritic enclave) were also analysed for Hf (...) Lire la suite »

Peritectic Garnet entrainment

Mercredi 30 septembre 2009, par Arnau // Articles Scientifiques

Experimental melt (glass) compositions indicate that most of the S-type granites of the Cape Granite Suite in South Africa have ferromagnesian contents too high to represent melts. Consequently, the composition of the more mafic granites demands the addition of an Fe- and Mg-rich component to the magma. The compositions of the granites evolve along well-defined trends away from the likely melt composition for many components plotted against Mg + Fe. An increase in A/CNK, Mg#, Ca, and HREEs, (...) Lire la suite »

Tracking S-type Granites : the fate of peritectic Garnet

Mercredi 30 septembre 2009, par Arnau // Articles Scientifiques

This study investigates, via a pseudosection approach, the conditions of formation of garnet in the leucogranitic to granodioritic S-type Cape Granite Suite (CGS), South Africa. Previous work has stressed the importance of peritectic garnet entrained from the anatectic source in the petrogenesis of these granites. In this study, garnet from S-type granites of the CGS, showing as little evidence for replacement as possible, was studied for major and trace element geochemistry. Surprisingly, (...) Lire la suite »

Trace elements composition of S-type granites

Mercredi 30 septembre 2009, par Arnau // Articles Scientifiques

Within individual plutons, the trace element concentrations in S-type granites generally increase with maficity (total iron and magnesium content and expressed as atomic Fe + Mg in this study) ; the degree of variability in trace element concentration also expands markedly with the same parameter. The strongly peraluminous, high-level S-type granites of the Peninsular Pluton (Cape Granite Suite, South Africa) are the product of biotite incongruent melting of a metasedimentary source near (...) Lire la suite »