 |
| Titel |
Macrocrystal populations retrieved from lamproites indicate accretion of young SSZ oceanic lithosphere in the assembly of W. Anatolia, Turkey |
| VerfasserIn |
Dejan Prelevic, Cüneyt Akal, Rolf Romer, Stephen Foley |
| Konferenz |
EGU General Assembly 2010
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250038080
|
|
|
|
|
|
| Zusammenfassung |
| Western Anatolian lithosphere comprises several sutures and major continental fragments
with Laurasian and Gondwanan affinities, assembled prior the Oligocene. One of the major
tectonic features shaping its structure is the Menderes metamorphic massif, which consists of
several assembled and imbricated terrains exhumed by the Late Miocene during the extension
that affected the entire Aegean province. A predominant opinion is that the Menderes is a
core complex delineated by low-angle detachment faults. An alternative explanation
associates it with shallow subduction of Neotethyan oceanic lithosphere that was later
delaminated. To distinguish between these possibilities, direct evidence from the
Western Anatolian mantle lithosphere would be ideal, because of the compositional
differences of the continental and oceanic mantle lithosphere. In the absence of
mantle xenoliths, mantle-derived volcanics and their macrocrystal populations, offer
the only information about the composition of the mantle-lithosphere under the
Menderes.
In this contribution, we constrain the mineralogy of the lithospheric mantle based on a
dataset for Western Anatolian lamproitic lavas and a systematical investigation of the major
and trace element distribution in their macrocrysts. The host lamproites are ultrapotassic,
high-Mg mantle-derived rocks, which show geochemical resemblance with the rest of
the Mediterranean lamproites. Two types of olivine macrocrysts are recognized:
Phenocrystal olivine has high-Fo cores (Mg# up to 94), very high NiO contents up
to 0.8 wt.%, low Cr2O3 (1 mm) mantle xenocrystal olivine contains
homogeneous core with plateau-like compositions (Mg# around 0.92, but NiO and
CaO contents |
|
|
|
|
|
|