Preliminary results on the geology, petrography and geochemistry of the Karaabalar Magmatic rocks in the Istranca Region, NW Turkey

Çalık A., Hanelçi Ş., Türkdönmez O.

European Geosciences Union, General Assembly 2010, Vienna, Austria, 2 - 07 May 2010, pp.14535

  • Publication Type: Conference Paper / Summary Text
  • City: Vienna
  • Country: Austria
  • Page Numbers: pp.14535
  • Çanakkale Onsekiz Mart University Affiliated: Yes


In this study, the Karaabalar magmatik rocks exposed between the town of Karaabalar and the town of Caglayık
(Kırklareli) was investigated to determine its petrological and geochemical characteristics. In the study area,
the basement lithologies are represented by the Paleozoic Korukoy formation that mainly consists of granitic
gneisses, granite with diabase dayks. The Triassic Kocabayır formation that consists of quartz - feldspar schist,
quartz-muscovite schist, and mica schist unconformably overlay the basement. The Kocabayır Formation passes
up Mahya formation that consists of calcschist, graphite schists and marble. The Jurassic Dolapdere formation lies
on the Mahya formation and mainly consists of black marble and calc-schist. These metamorphic rocks cut by the
Upper Cretaceous - Karaabalar magmatic rocks in the studied area.
On the basis of petrographical investigations, the common mineral assemblages of the Karaabalar magmatik
unit are mainly made up of quartz + alkali feldspar (Orthoclase, microcline) + muscovite + biotite  opaque
minerals. Sericite and epidote excite as secondary mineral.
The Karaabalar magmatik unit generally ranges from granodiorite and quartz-monzonite to granite. Geochemical
data obtained from whole-rock samples show that the rocks of the Karaabalar magmatik unit are
generally peraluminus with 64 – 75 wt % SiO2, 13 – 16 wt % Al2O3, 0.4 – 1.7 wt % CaO, 3 -5 wt % Na2O, 3 – 5
wt % K2O and characterized by enrichment in LREE and LILE and relative depletion in HFSE (e.g. negative Nb
and Ta anomalies). LILE concentrations are generally greater, and Ti, Zr, P, Sr and Ba concentrations are smaller
than those of normal arc granites, except for Nb and Y. These characteristics indicate a mature arc or collision
affinities rather than normal arc granites. Geochemical discrimination diagrams also imply a volcanic arc and/or a
collisional tectonic setting for the Karaabalar Granitoids.