Granitic gneiss in a Miocene extensional core complex on Naxos locally
preserves primary igneous textures. On an outcrop scale, these includ
e mafic enclaves; in thin section, feldspar phenocrysts contain unorie
nted accessory mineral inclusions. The gneiss is interpreted as having
a Hercynian granite protolith. Contrary to previous accounts, migmati
tes are rare in the gneiss. The granite is geochemically similar to po
st-collisional extension-related granites and differs from the predomi
nant granodiorites found in the Hercynian basement of northwestern Gre
ece. An I-type hornblende-biotite granite pluton was emplaced during M
iocene extension in western Naxos. It is a typical subduction-related
pluton emplaced under conditions of back-are extension. The pluton is
cut by later leucogranite that geochemically resembles the granite dyk
es that cut the migmatites. In northern Naxos, minor leucogranite intr
usions are of two geochemical types. One is everywhere deformed and ge
ochemically resembles the leucogranite that cuts the Western pluton. T
he other is variably deformed and new geochronology shows that it has
an age of 10 Ma. (C) 1997 by John Wiley & Sons, Ltd.