Recent studies on accessory allanite, (Ce,Ca,Y)2(Al,Fe3+,Fe2+)3(SiO4)3(OH), in granitoids have revealed an attractive potential of the mineral giving clues to the petrogenesis and post-magmatic history of the host rocks. Allanite is also known as important repository for the actinide elements as Th and U in granitoid rocks, which makes it, together with monazite and zircon, a promising object for conventional and local age dating. The present work considers the occurrence, chemical composition and petrogenetic implication of allanite from porphyroid granitoids outcropping near to Skrut village in Belassitsa Mountain (Bulgaria, Ograzhden block, Serbo-Macedonian massif - SMM). the Skrut granitoids are the first evidence for the Jurassic magmatism in the Ograzhden block of SMM. Granitoid plutons of Jurassic age have also been established in other parts of SMM (Arnea intrusion) as well as in the neighboring tectonic units as the Vardar-Axios zone (Fanos, Furka and Stip intrusions). In this respect, the data on allanite from the Skrut granitoids will be useful for a further detailed comparison of and correlation between the Jurassic magmatisms in the region.
Both types of allanite, established in the Skrut granitiods, are indicators for early stages of magmatic history of the intrusive. The answer whether the proposed scenario of the earlier evolution of the magmatic system is true or not, may be attained performing a further detailed study of allanite and other accessory minerals accenting on their crystal chemistry, defect structure, and isotopic composition.
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