Granity typu A w kompleksie mazurskim — przyczynek do dyskusji o klasyfikacji granitów

Aleksandra Gawęda, Ewa Krzemińska, Janina Wiszniewska


A-type granites in the Mazury Complex — contribution to world-wide discussion on granite classification.
A b s t r a c t . The modern geochemical classification of granitic rocks is based upon diverse criteria such as: mineralogy, geochemistry, tectonic environment and their origin. The alphabetic classification of S, I, M and A-type granites have been used to facilitate recognition of the origin, chemical composition and geotectonic setting. Of these, the A-type term has generated worldwide discussions in petrological communities. The authors discuss the geochemical, mineralogical and geotectonic features as well as the question of source rocks and co-genetic rock complexes of A-type granites at the example of the Mazury granitoid complex. The Mesoproterozoic Mazury Complex from the crystalline basement of East European Craton represents A-type group of granitoids, plotting in WPG (Within Plate Granites) and A2 type fields. The obtained results confirm usability and at the same time practical diagnostic value of the term of A-type for defining a special type of granites, distinguishable from the other ones.

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