Zircon typology in granitoid rocks of the Ditró massif, Transylvania, Romania

The complex magmatic body of the Ditro Massif (Transylvania, Romania) was formed between the Middle Triassic and Lower Cretaceous times. Granitoid rocks can be found in a large area in the NE part of the massif. They were formed either by differentiation of an upper mantle ultramafic intrusion or by...

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Bibliographic Details
Main Authors: Kovács Gábor
M. Tóth Tivadar
Format: Article
Published: University of Szeged, Department of Mineralogy, Geochemistry and Petrology Szeged 1999
Series:Acta mineralogica-petrographica 40
Kulcsszavak:Kőzettan - Erdély, Ásványtan, Földtan
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Online Access:http://acta.bibl.u-szeged.hu/24877
Description
Summary:The complex magmatic body of the Ditro Massif (Transylvania, Romania) was formed between the Middle Triassic and Lower Cretaceous times. Granitoid rocks can be found in a large area in the NE part of the massif. They were formed either by differentiation of an upper mantle ultramafic intrusion or by assimilation of crustal material. By the zircon morphological study it was stated that the most frequent zircon types in the granitoid rocks are P4,P5, P3, Pi<), P24 and D. This suggests that the zircon crystals could be formed in hyperalkaline or hypoaluminous environment at high (800-850 °C) temperature. On the basis of the calculated I.A. and I.T. values the studied granite belongs to the alkaline field, close to the alkaline-subalkaline boundary. This indicates an upper mantle origin in the Pupin's system, therefore, granites are supposed to be differentiation products of an upper mantle ultramafic body.
Physical Description:45-53
ISSN:0365-8066