Altersbeziehungen zwischen Metamorphose und Deformation im zentralen Teil des Serbomazedonischen Massivs (Vertiskos Gebirge, Nord-Griechenland)

Abstract

Mit 5 Abbildungen und 3 Tabellen ZusammenfassungIm mittleren Teii des Serbomazedonischen Massivs, n6rd-lich des Volvi Sees im Vertiskos Gebirge, wurde ein amphibolitfazielles syn-bis sp~tkinematisches metamorphes Ereignis (Kr~) festgestellt, welches dutch fast selger stehende bzw. steil nach N fallende isoklinale Scherfalten gekennzeichnet ist. Auf diese erste Hauptmetamorphose folgt ein zweiter epizonaler syntektonisch metamorpher Akt (Kr2), welcher durch flach geneigte, NNW-SSE bis NNE-SSW streichende Stauchfalten charakterisiert ist. Schlieglich folgt ein drittes, schwach temperiertes Ereignis (Diaphthorese Kr3). Dieses erfaf~te die meisten Gesteinsserien des Gebietes. Es kann sowohl als Ausklang der Kr2-Kristallisation oder als ein zeitlich abgetrenntes Ereignis angesehen werden. K/At-und Rb/Sr-Analysen an Hellglimmer, Biotiten und Hornblenden lassen den Schlug zu, dag die Kr2-Kristallisation und die damit verbundene T2-Deformation eher kretazischen Alters sind, w~ihrend die Krs-Krlstallisation und die damit verbundene T1-Deformation vorkretazischen Alters sein dfirfte. AbstractThe relations between metamorphism and deformation of the crystalline rocks in the central part of the Serbomacedonian mass (mountain Vertiskos), are studied. It is found a syntectonic -amphibolific metamorphic phase (Kr~) in reference to a folding phase (T~), characterized by almost vertical isoclinal shear-folds. This main metamorphism was followed by a syntectonic metamorphism of green schist facies (Kr2) in relation to a folding phase (T2), characterized by slightly inclined fractured folds, directied NNW-SSE to NNE-SSW. Finally, a very low grade metamorphic event (Diaphthorese, Kr3) influenced the whole rocks of the area. It can be regarded either as the final stage of the Kr 2 phase or as a younger and distinct metamorphic event. The K/Ar and Rb/Sr datation of the white micas, biotites and hornblends showed that the Kr2 phase is of Cretaceous age and so the Kr, phase must be older than Cretaceous.

Cretaceous-Tertiary structures and kinematics of the Serbomacedonian metamorphic rocks and their relation to the exhumation of the Hellenic hinterland (Macedonia, Greece)

“…1) provide the earliest limit for the onset of the normal faults bounding the basins. Furthermore, tectonic basins with Eocene to Oligocene clastic sediments bounded by NW/SE to WNW/ESE-trending high-angle normal faults are developed on the Circum-Rhodope belt (Papadopoulos 1982;Karfakis and Doutsos 1995). Recently, Roussos (1995), using seismic and drilling data, proposed that parts of the Axios basin in the western part of the SRB started to form during Middle Eocene times.…”

The a-Type Kerkini Granitic Complex in North Greece: Geochronology and Geodynamic Implications

“…The K-Ar ages on micas and the Rb-Sr age on biotite can be interpreted by a metamorphic/fluid event at about 133 Ma. K-Ar and Rb-Sr mica ages of 102 to 131 Ma obtained from Vertiscos rocks were interpreted (Papadopoulos and Kilias 1985) to reflect a retro grade and deformation event or a lower Cretaceous rejuvenation (Frei 1992). The last event was considered by Sakellariou (1989) equal to the regional lower amphibolite facies metamorphic event responsible for the main structural overprint iji the SMM rocks.…”

Inferences on the Mesozoic evolution of the North Aegean from the isotopic record of the Chalkidiki block

“…Part of these outliers were indeed originally mapped as part of the Circum-Rhodope belt (Kockel et al, 1977; see also Dixon and Dimitriadis, 1984) but re-interpreted later as individual units under various local names such as the "Nea Madytos Unit" of Sakellariou and Dürr (1993) or the "Bunte Serie" of Papadopoulos and Kilias (1985). This basement-cover complex lies beneath a thin basement fragment through a sharp NW-trending thrust contact (Kydonakis et al, 2015b) ( Fig.3).…”

“…The Arnea-Kerkini Magmatic Complex intruded the Vertiskos Unit during the Early Triassic (Himmerkus et al, 2009b) and both, as a coherent basement complex, experienced the same post-intrusion metamorphic overprint(s) (Burg et al, 1995;Kilias et al, 1999). Metamorphic K-Ar ages range between 140 and 90 Ma (e.g., Borsi et al, 1965;Harre et al, 1968;Marakis, 1969;Papadopoulos and Kilias, 1985;Christofides et al, 1999) (Fig.4). Rubidium/strontium metamorphic ages show intense dispersion and a number of non-reset Permian -Jurassic ages but the youngest age cluster correlates well with the Cretaceous K-Ar metamorphic ages (e.g., Zervas et al, 1979;Papadopoulos and Kilias, 1985;de Wet et al, 1989) (Fig.4).…”

“…Metamorphic K-Ar ages range between 140 and 90 Ma (e.g., Borsi et al, 1965;Harre et al, 1968;Marakis, 1969;Papadopoulos and Kilias, 1985;Christofides et al, 1999) (Fig.4). Rubidium/strontium metamorphic ages show intense dispersion and a number of non-reset Permian -Jurassic ages but the youngest age cluster correlates well with the Cretaceous K-Ar metamorphic ages (e.g., Zervas et al, 1979;Papadopoulos and Kilias, 1985;de Wet et al, 1989) (Fig.4). Lips et al (2000) reported a 143 ± 5 Ma 40 Ar/ 39 Ar age (white mica; plateau age) from a quartz-calcite mylonite and de Wet et al (1989) a 136 ± 1 Ma (biotite; plateau age) from the Arnea Magmatic Complex (Fig.4).…”