 |
| Titel |
Geochemistry and Sr-Nd-Pb isotopic characteristics of mantle xenoliths of Hacikoy and Karatepe alkaline lavas in Thrace Region (NW Turkey) |
| VerfasserIn |
Işıl Nur Güraslan, Alp Ünal, Safak Altunkaynak |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250146650
|
| Publikation (Nr.) |
 EGU/EGU2017-10685.pdf |
|
|
|
|
|
| Zusammenfassung |
| Late Miocene basaltic lavas of Thrace region in NW Turkey contain abundant ultramafic
xenoliths that provide important data about the never completely understood composition of
the upper mantle. We present new major-trace element geochemistry and Sr-Nd-Pb isotope
data from peridotite xenoliths within the alkaline basaltic rocks from Hacı köy and Karatepe
basalts that crop out near the Tekirdağ and Çorlu in order to understand the origin of the
Thrace basalts and nature of mantle beneath NW Turkey. The peridotite xenolith samples
from those vary from spinel-harzburgite (70-80% olivine, 20-30% orthopyroxene, 5-10%
spinel) to spinel-dunite (90% olivine, 5-10% spinel) due to the modal composition
analysis.
The peridotite xenoliths have average MgO content of 42.43 wt. % and Al2O3 content of
1.15 wt. %. CaO content of the peridotite xenoliths show that they are strongly depleted (av.
1.22 wt. %). They are enriched in large ion lithophile elements (LREE) and depleted in
HREE. Xenoliths are characterized by more uniform isotopic compositions compare to
host basalts. Their measured average 87Sr/86Sr ratio is 0.703891, and 143Nd/144Nd
value is 0.513160. The 206Pb/204Pb and 207Pb/204Pb values are 18.476 and 15.553
respectively.
These petrographical, geochemical and isotopic characteristics collectively indicate an
enriched subcontinental lithospheric mantle beneath NW Anatolia. Our results are consistent
with the Re-Os isotope results obtained from mantle xenoliths of the previous studies,
concluding in a lithospheric mantle source. And this lithospheric mantle appear to have
contributed to the Late Miocene alkaline volcanism as a result of crustal thinning associated
with extension in NW Anatolia. |
|
|
|
|
|
|