de L. PAVELESCU1, G. POP2, G. AILENEI2, I. CRISTEA2, M. SOROIU3
1Universitatea din Bucuresti, Facultatea de Geologie si Geografie, Catedra
de Mineralogie
2Intreprinderea Metalelor Rare, Bucuresti
3Institutul de Fizcia Atomica, Bucuresti
EVOLUTION OF THE CRYSTALLINE NUCLEUS OF THE EAST CARPATHIANS
IN THE LIGHT OF RADIOMETRIC DATING
(Abstract)
The radiometric ages obtained on minerals and rocks belonging to the crystalline nucleus of the East Carpathians point out the metamorphic recrystallization of these minerals and rocks during the Hercynian and Alpine orogenies. The metamorphism of the Hercynian series is characterized by granitization processes along the Eastern alignment of the nucleus under PT° conditions corresponding to the biotite and potassium feldspar isogrades. The alpine recrystallization within the biotite-staurolite-sillimanite isogrades is localized in the Western half of the nucleus and probably affected the sedimentary Triassic deposits as well. The basic and ultrabasic igneous rocks intruded into the Hercynian recrystallized series differ by their chemistry from the lamprophyres intruded into the metamorphic rocks recrystallized during the Alpine orogeny.