There are two major styles of Jurassic granitic magmatism associated with the Vardar Zone ophiolites: (1) strictly intra-ophiolitic intrusions dominating in the northern part and (2) magmatic bodies intruding both ophiolites and the basement in the southern part.
The intra-ophiolitic granitoids occur near Ždraljica and Kuršumlija (Serbia) and form dykes and small irregular bodies cutting gabbro-diabase ophiolite complexes. Geochemically, three subgroups are distinguished: (i) intermediate rocks, (ii) low-Sri granites and (iii) high-Sri granites. Intermediate rocks are represented by diorites, quartz diorites and quartz monzodiorites with Sri=0.70557 – 0.70746 and εNd(T) -4.5 – -0.8. The low- and high-Sri granites are petrographically similar, but differ in isotope composition, i.e., Sri=0.70330 – 0.70767 and εNd(T) -5.1 – 1.5 and Sri=0.70956 – 0.71602, εNd(T) -6 – -5.1, respectively.
Furthermore, the high-Sri granites have higher HREE and Y contents.
The southern granitoids in F.Y.R. of Macedonia and Greece (Fanos) form large bodies that intrude both the Vardar Zone ophiolites and metamorphic rocks of the Serbo-Macedonian Massif. The rock suite of F.Y.R. of Macedonia includes intermediate to acid members (diorite, quartz monzodiorite, granite) and shows a trend of decreasing radiogenic εNd(T) - (3.3 – -8.9) and increasing Sri (0.70740 – 0.71588) with increasing silica content. In contrast, the Fanos granite is isotopically relatively uniform with Sri=0.70516 – 0.70559 and εNd(T) = -1.6 – -0.7.
Geochemical modeling suggests that the high-Sri granites derived from peraluminous magmas that were generated by obduction-induced melting of (meta) sedimentary rocks. The low-Sri granites and the intermediate rocks of Serbia formed separate, possibly small, magma chambers, partly related to obduction-induced melting of a low-Sri source, formed in part by subduction related volcanic arc magmatism.
Granitic magmatism in the southern part of the Vardar Zone is characterized by melting of slightly enriched mantle- and lower crustal magmas that were modified by AFC processes in F.Y.R. of Macedonia and FC processes in Fanos. Their emplacement was favored by collisional processes resulting in great crustal thickness and the post-collisional emplacement of mantle-derived magmas that provided the heat for partial crustal melting.