The morphology and chemistry of K-feldspar megacrysts from Ikizdere Pluton: evidence for acid and basic magma interactions in granitoid rocks, NE-Turkey

KARSLI O., AYDIN F., Sadiklar M. B.

CHEMIE DER ERDE-GEOCHEMISTRY, vol.64, no.2, pp.155-170, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 64 Issue: 2
  • Publication Date: 2004
  • Doi Number: 10.1016/j.chemer.2003.02.001
  • Journal Name: CHEMIE DER ERDE-GEOCHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.155-170
  • Keywords: K-feldspar megacryst, mafic and felsic magma, Eastern Pontides, mafic injection, MINERALS, EVOLUTION, PONTIDES, GEOLOGY
  • Karadeniz Technical University Affiliated: Yes

Abstract

Ikizdere Pluton consists of granite, granodiorite, tonalite, monzonite, quartz monzonite containing pinkish colored K-feldspar megacrysts (KFMs). The crystal sizes of the KFMs range from 1 to 4 cm. The lath-shaped megacrysts are uniformly (i.e., randomly) distributed in the host plutonic rocks and have mafic and felsic inclusions whose crystal sizes are smaller than 1 mm. The crystal inclusions are biotite, slightly annitic in composition with X-Mg[=Fe-tot/(Fe-tot+Mg)]=0.50-0.58, amphibole (magnesio-hornblende, X-Mg[=Mg/(Mg+Fe-tot)]=0.70-0.79), iron-titanium oxide (low titanium magnetit and ilmenite), plagioclase (Ab(75-25)An(65-35)) and as minor quartz. The compositions of the KFMs range from Or(95)Ab(5)An(0) to Or(82)Ab(17)An(1). BaO contents of the megacrysts increase from core to rim, The mafic and felsic inclusions are compositionally similar those of the host rocks.