Research Information System
INTERNATIONAL GEOLOGY REVIEW, vol.66, no.12, pp.2195-2215, 2024 (SCI-Expanded)
The timing of
extensional events in northern Gondwana remains elusive. In relations to this
event, a new zircon U-Pb age and Hf isotopic compositions, and whole-rock
geochemistry provided here for the amphibolites in the basement unit of the
Menderes Massif (MM) within the Anatolide-Tauride Block (ATB). LA-ICP-MS U-Pb zircon
dating of one sample yielded a crystallisation age of 367.0±2.5 Ma, providing the
first record of Late Devonian (Famennian) mafic magmatism in the Menderes
Massif. This sample contains inherited zircon grains with ages spanning from
588 Ma to 541 Ma, likely sourced from late Neoproterozoic country rocks. Chondrite-normalized
rare earth element patterns exhibit enrichment in light rare earth elements and
flat patterns for heavy rare earth elements, suggesting affinities with
tholeiitic EMORB and ocean island basalt. The geochemical data, coupled with the positive
εHf(t) values ranging from 0.5 to 7.8, indicate that the amphibolite likely
originated from juvenile melts generated by partial melting of the
asthenospheric mantle. This melt was subsequently modified by crustal
contamination and fractional crystallization. Contemporaneous EMORB- and
OIB-like mafic rocks are identified in the eastern Taurides and Iran,
respectively. Both regional geological and geochemical evidence
propose that Late Devonian magmatism in the Anatolide-Tauride Block occurred
in a within-plate tectonic setting. This magmatic activity might have been
triggered by the northward subduction of the Paleotethys beneath the Pontides
during the Devonian, a process that would produce a slab-pull force, creating
an extensional tectonic regime along the northern margin of Gondwana.