Sarackoy Volcanic Suite: implications for the subductional phase of arc evolution in the Galatean Arc Complex, Ankara, Turkey


Kocyigit A., Winchester J., Bozkurt E. , Holland G.

GEOLOGICAL JOURNAL, cilt.38, ss.1-14, 2003 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 38 Konu: 1
  • Basım Tarihi: 2003
  • Doi Numarası: 10.1002/gj.921
  • Dergi Adı: GEOLOGICAL JOURNAL
  • Sayfa Sayıları: ss.1-14

Özet

A sequence of upper Campanian volcanic rocks, hitherto considered as part of the Miocene calc-alkaline Galatean volcanic sequence, crops out near Sarackoy, 40 km north of Ankara. These volcanic rocks, unconformably overlain by Eocene nummulitic limestones, comprise thin flows and volcaniclastic deposits. They can be divided compositionally into three distinct subunits: (i) basal massive trachyandesitic volcaniclastic rocks with a thin flow at the top, overlain by (ii) mixed volcaniclastic rocks and thin amygdaloidal flows of alkali basaltic composition, with (iii) trachyandesitic flows and subordinate volcaniclastic rocks at the top. This alkaline volcanic activity, associated with late Campanian forearc peripheral sedimentation, is indicative of late Campanian extension within a collisional regime, pre-dating the compression accompanying Galatean arc development.