Geology and geochemistry of the pre-Early Cambrian rocks in the Sandikli area: Implications for the Pan-African evolution of NW Gondwanaland


Gursu S., Goncuoglu M., Bayhan H.

GONDWANA RESEARCH, vol.7, no.4, pp.923-935, 2004 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 7 Issue: 4
  • Publication Date: 2004
  • Doi Number: 10.1016/s1342-937x(05)71075-3
  • Title of Journal : GONDWANA RESEARCH
  • Page Numbers: pp.923-935

Abstract

The pre-Early Cambrian Sandikli Basement Complex in western Central Anatolia comprises a low-grade metasedimentary succession (Guvercinoluk Formation) and meta-rhyolites intruded by meta-quartz porphyry rocks (Kestel Cayi Porphyroid Suite). The Guvercinoluk Formation consists of alternation of meta-siltstones and meta-sandstones with olistostromal conglomerates, rare black chert and cherty meta-dolomite lenses. The Kestel Cayi Porphyroid Suite is a deformed, highly sheared dome-shaped rhyolitic body with quartz porphyry rocks. Quartz porphyry dykes intrude both the volcanic carapace and the meta-sedimentary rocks of the Guvercinoluk Formation. Both the meta-quartz porphyry rocks and meta-rhyolites are typically mylonitic with relict igneous textures. Geochemical data indicate that the felsic rocks of the Kestel Cayi Porphyroid Suite are subalkaline and display characteristic features of post-collisional, I-type granitoids. The basement complex is unconformably overlain by variegated conglomerates, mudstones and arkosic sandstones with andesitic lavas, followed by siliciclastic rocks and carbonates that yielded Early Middle Cambrian fossils.