The kinematic of the Cretaceous deformation and the relationship between deformation and metamorphism of the Pelagonian crystalline was studied in Voras Mt (northern Greece). The Pelagonian crystalline in this area has been subdivided into a lower, core part, consisting mainly of gneissic rocks and schists and an upper, cover part, consistine of schists and quartzites with marble intercalations. Intensely deformed granitic rocks of Upper Paleozoic age intrude the Pelagonian crystalline basement. An S j foliation is the oldest fabric recognized in the Pelagonian crystalline. Sj is mainly defined by syn-Sjgarnet(Gr1), biotite(Btj), white mica (Wnij), chloritoid, kyanite and plagioclase in the metapelitic rocks and green amphibole, epidote, plagioclase, and biotiteiBtj) in the amphibolite. Garnet grows also in some cases post-kinematically. Ilmenite and tourmaline are often found in the pelitic rocks as well. S is overprinted by an S2 foliation that developed as a crenulation cleavage. In most places, however, S2 has destroyed all earlier fabrics and a single S2 fabric is present related to, isoclinal or sheath folds intrafolial in places. S2 in the metapelitic rocks is characterized by the syn-S2 development of chlorite, white mica(Wm2) and plagioclase. In the amphibolite S2 is mainly defined by the syn-kinematic development of actinolite, plagioclase, biotite(Bt2), white mica(Wm2) and chlorite. During D2 garnet(Gr1) and biotiteiBtj) are partially replaced by chlorite, while green amphibole is replaced by actinolite and chlorite. Chloritoid remains generally stable along the S2-planes but in some places transforms to chlorite and sericite. Furthermore, D2 was locally followed by a static post-kinematic annealing indicated by polygonal quartz microfabrics with equilibrated grain boundaries and triple points. The overall orientation of S2 is dome shaped with a gentle SW-ward and NE-ward dip in the southwestern and northeastern flanks of the dome respectively. Syn-S2 minerals defined a very well exposed NW-SE trending stretching lineation. Kinematic indicators show a main top to the SE sense of movement. An S3 crenulation cleavage associated with asymmetric NW-SE trending folds is also present in most parts of the core and cover rocks, possibly, related to a constrictional type of deformation. A well developed, S4 shear band cleavage is mainly present in the upper parts of the metamorphic dome and formed under cooler conditions. S4 shear bands are associated with a NW-SE developed stretching lineation defined by elongated and dynamically recrystallized quartz grains and a preferred orientation of white mica and chlorite. Along the S4 shear bands a transformation of garnet, biotite, chloritoid and amphibole into chlorite is always observed. S4 shear bands indicate a main top to the SE sense of movement. The P-T metamorphic conditions were derived from textural equilibria and mineral assemblages, as well as from the spatial distribution of the metamorphic minerals. Syn-Dj metamorphism reached the conditions of the boundaries between greenschist and amphibolite facies. Syn-D2 retrogression took place under greenschist facie conditions. K/Ar radiometric datings on coarse-grained syn-St and younger fine-grained syn-S2 micas define an Early Cretaceous cooling age ('135Ma) for the older event and a Mid- to Late Cretaceous age ('90-80Ma) for the second event. A white mica age of ca. 65Ma correlates with S4 shear band clevage. Furthermore, the intrusion age of a granitic body into the Pelagonian crystalline is dated using the Pb/Pb single zircon evaporation method. The estimated intrusion age of 300±3Ma suggests that the Pelagonian crystalline was affected by a pre-kinematic magmatic activity relative to its Cretaceous deformation.

The Hellenic orogen consists of three orogenic belts: 1) the Cimmerian orogenic belt, including Rhodopian, Serbomacedonian, Circum Rhodope, Axios and Pelagonian zones, is the internal belt which has been created in pre-Late Jurassic times as a result of the northward drift of Cimmerian contrinental fragments from Gondwana towards Eurasia. Ophiolites from small ocean basins were mainly emplaced onto the Cimmerian continental margins in Middle Jurassic. 2) the Alpine orogenic belt, including External Hellenides and Pindos-Subpelagonian ophiolites and oceanic sediments (Neo-Tethyan), which has been created in Cretaceous-Paleogene times after the subduction of the Neotethyan oceanic crust beneath the Cimmerian-Eurasian plate and the collision of the Apulian microplate to the later, 3) the Mesogean orogenic belt along the External Hellenic orogenic arc as a result of the Mesogean-African underplate beneath the unique Alpine-Cimmerian-Eurasian plate in Miocen- Pliocene times and the exhumation of the Cretan-Southern Peloponesus tectonic windows. Structural analysis and detailed studies of the geometry and kinematics suggest that during Alpine-Mesogean orogenic process a SW-ward migration of successive complessional and extensional tectonic events took place resulted of successive subductions. Thus, crustal thickening produced by compressional tectonics in each area was followed by an extensional exhumation of underplate rocks as tectonic windows.

The Tzena Mt. belongs to the Paikon subzone (Axios zone, Central Macedonia, Greece) and consists of 5 distinguishable lithological units, which are from the lower to the upper the following: the lower unit of gneisses, the marbles unit, the black phyllites, the meta-volcanosedimentary unit and the meta-flysch. These units form a metamorphic sedimentary sequence of Upper Paleozoic to Lower Cretaceous age, while the metarhyolites of the volcanosedimentary unit are of Jurassic age. Kinematic analysis of the deformation in Tzena Mt. suggests that the whole metamorphic sequence has been affected by a strong shearing and mylonitisation in ductile to semi-ductile conditions, trending SW-NE, contemporaneous with a retrograde metamorphism in greenschist facies. Kinematic indicators show sense of movement both top to the SW and NE while a streching lineation, trending SW-NE, defined by preferred orientation of white mica and chlorite remains stable all over the metamorphic sequence. The Upper Cretaceous carbonates of the adjacent to Tzena, Pinovon Mt., have been affected by this deformation as well, and hence the deformation took place in Tertiary times. However, the contact between the lower gneiss unit and the marbles unit constitute a shear zone, in ductile to semi-ductile conditions, trending SW-NE with a sense of shear top to the SW. Thus, the marbles have been moved upon the gneisses along a large shear zone towards SW, during the Tertiary deformation. Correlation between this tertiary SW-NE deformation event in Tzena Mt. with the similar tertiary shear deformation towards SW in Paikon Mt., suggests that Tzena and Paikon Mts. have the same tectonic history in Tertiary times. Analogous Tertiary tectonic events with similar geometry and kinematics of the deformation have already been established for several other areas in Greece (Olympos - Ossa Mts., Rhodope Mt., Cyclades islands etc.) where they have caused the exhumation of metamorphic core complex (Kilias & Mountrakis, 1990, Sokoutis et al., 1993, Kilias, 1995, Dinter, 1998, Kilias et al., 1999). Thus, in relation to these, an exhumation of the Tzena orogen, consisting of the metamorphic sequence, during the Tertiary extensional tectonic process could be very possible.

The Ercynian plutonio rocks intruding the Paleozoic basement of the Pelagonian zone in the area of Kaimaktsalan (western Voras Mt.) are examined. They are composed of: hornblende-biotite granodiorites to granites (Hb)BtGrd, biotite granites (BtGr), monzonitic to monzodioritic mafic enclaves (MME) and leucogranites (LGr). The (Hb)BtGrd and BtGr are randomly distributed and exhibit transitional contacts, while both are intruded by the LGr. In the (Hb)BtGrd two types of biotites were found; one similar to MME biotites and another similar to BtGr. The amphiboles are magnesiohornblende and edenite. The Nb vs. Y and Rb vs. Y+Nb plots of the rock-samples indicate the strong relationship of both (Hb)BtGrd and BtGr with a volcanic arc (VAG) geotectonic setting, while the LGr are plotted in the syn-collision (syn-COLG) field. Both the (Hb)BtGrd and BtGr are plotted in the field of the pre- or post-collisional granites, whereas the LGr reveal the characteristics of the syn-collisional anatectic granites (R1-R2 diagram). The majority of the major elements show wellcorrelated trends with differentiation starting from the more basic MME up to the LGr or the BtGr while, the behaviour of trace elements is characterized by significant changes between MME and (Hb)BtGrd+BtGr. The Kaimaktsalan granitoids show calc-alkaline affinity. The Rb/Sr vs. 1/Sr and Rb/V vs. 1/V display straight line trends for (Hb)BtGrd+BtGr indicative of mixing processes. Based on the field observations, mineralogical composition and geochemistry of the rock types, a two-stage process for the formation of MME, (Hb)BtGrd and BtGr is suggested. In the first stage, a basic magma of mantle origin, and composition similar to the more basic MME underwent fractional crystallization, while it was mixed with an acid magma of crustal origin and composition similar to the most acid BtGr. This mixing-fractional crystallization (MFC) process has low r, due to the difference in composition and viscosity of the two magmas. This process resulted in the formation of the most basic (Hb)BtGrd. In the second stage, the resulted magma was fractionated and mixed with the fore mentioned crustal magma, but with higher (r) giving the (Hb)BtGrd and BtGr. Sub-parallel and crosscutting trends between the LGr and BtGr suggest that the former do not represent an evolved magma of the latter, but a separated intrusion. Four main deformational events (Di, D2, D3 and D4) of Alpine age and plastic to semi-plastic conditions affected the crystalline basement of the Pelagonian zone in the broader area of the Voras Mt. as well as the Ercynian plutonio rocks. The Drevent is related to a Late Jurassic-Lower Cretaceous Si-schistosity associated with Mi-paragenesis of Qtz+Kf+Ab+Phe+Bt+Hb+ Ep/Czo±Tit±Garn. During the Middle Cretaceous the Si-schistosity was overprinted by an S2-axial plane schistosity of tight, recumbent to inclined B2-folds (D2-event). The S2-schistosity has NW-SE strike and dips either towards the SW or NE. It is characterized by the syn-kinematic growth of Wm+Chl+Ab+Act+Qtz+Ep (M2-paragenesis) that forms an L2-stretching lineation striking NW-SE closely related with a transport direction towards the SE. The M1-paragenesis along the Sischistosity indicates that the Di event took place in the upper greenschist-lower amphibolitic metamorphic fades (~450-550°C). Also, the composition of the syn-Si phengite (max Si: 6,8) shows that the granites and orthogneisses of the crystalline basement of Kaimaktsalan have been metamorphosed in relatively high-pressure conditions (~8kb). The replacement of Bt with Chi and Hb with Act and Chi indicates that the M2-paragenesis took place below the ~450°C. The D2-event was succeeded by a younger D3-event that took place in semi-plastic conditions in Late Cretaceous. The D3-event is characterized by NNW-SSE to NE-SWextensional Sb3-shear zones and a stretching lineation associated with a top to the SE sense-of-shear. During the Tertiary and in more cold conditions, NW-SE striking Sb4-shear zones with ultra-cataclastites and sense-of-shear mainly top to the SW were formed due to the Drevent affecting all the previous structures.