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, vol.38, no.1, pp.1-14, 2003 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 38 Issue: 1
  • Publication Date: 2003
  • Doi Number: 10.1002/gj.921
  • Journal Name: GEOLOGICAL JOURNAL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1-14
  • Keywords: Sarackoy, Galatean arc magmatism, subduction, active margin, late Campanian, Turkey, ANATOLIAN FAULT ZONE, TECTONIC EVOLUTION, BASIN, NORTHEAST, GEOLOGY, DISCRIMINATION, GEOCHEMISTRY, PROVINCE, TETHYS, ROCKS
  • Middle East Technical University Affiliated: Yes

Abstract

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.