Skip to Main Content
Book Chapter

Constraints on Variscan and Cimmerian magmatism and metamorphism in the Pontides (Yusufeli–Artvin area), NE Turkey from U–Pb dating and granite geochemistry

By
Timur Ustaömer
Timur Ustaömer
1
İstanbul Üniversitesi, Mühendislik Fakültesi, Jeoloji Bölümü, Avcılar 34320, İstanbul, Turkey
Search for other works by this author on:
Alastair H. F. Robertson
Alastair H. F. Robertson
2
University of Edinburgh, School of GeoSciences, Grant Institute, Edinburgh EH9 3JW, UK
Search for other works by this author on:
P. Ayda Ustaömer
P. Ayda Ustaömer
3
Yıldız Teknik Üniversitesi, Doğa Bilimleri Araştırma Merkezi, Davutpaşa, İstanbul, Turkey
Search for other works by this author on:
Axel Gerdes
Axel Gerdes
4
Institute für Geowissenschaften, Goethe Universität, Altenhöferallee 1, 60438, Frankfurt am Main, Germany
5
Department of Earth Sciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
Search for other works by this author on:
Irena Peytcheva
Irena Peytcheva
6
Bulgarian Academy of Sciences, Geological Institute ‘Strashimir Dimitrov’, Acad. G. Bonchev St, Bl 24, 1113 Sofia, Bulgaria
Search for other works by this author on:
Published:
January 01, 2013

Abstract

Metamorphic and igneous rocks exposed in NW-vergent thrust sheets and their autocthonous basement in the NE Pontides were dated by the U–Pb method using zircons, supported by geochemical data for granitic rocks. Two meta-sedimentary units (Narlık schist and Karadağ paragneiss) yielded detrital zircon populations of 0.50–0.65 and 0.9–1.1 Ga, suggesting an affinity with NE Africa (part of Gondwana). The youngest concordant zircon age is Ediacaran for the schist but Devonian for the paragneiss, bracketing the paragneiss depositional age as Mid-Devonian to Early Carboniferous. Metamorphic rims of zircon cores in the paragneiss gave Carboniferous ages (345–310 Ma). The zircon rim data indicate two Variscan metamorphic events (334 and 314 Ma) separated by a hiatus (320–325 Ma). Granite emplacement took place during early Carboniferous, Early Jurassic and Late Jurassic phases. The crystallization age of the early Carboniferous granites (c. 325 Ma) corresponds to a hiatus in the zircon age data that could reflect subduction slab break-off. The Variscan granitic rocks intruded a Gondwana-derived continental terrane that was loosely accreted to Eurasia during early–late Carboniferous time but remained isolated from Eurasian-derived terrigenous sediment. In contrast, the Jurassic granitic magmatism relates to later back-arc extension along the southern margin of Eurasia.

Supplementary material:

Full isotope data (8 tables) are available at http://www.geolsoc.org.uk/SUP18558

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Geological Development of Anatolia and the Easternmost Mediterranean Region

A. H. F. Robertson
A. H. F. Robertson
Search for other works by this author on:
O. Parlak
O. Parlak
Search for other works by this author on:
U. C. Ünlügenç
U. C. Ünlügenç
Search for other works by this author on:
Geological Society of London
Volume
372
ISBN electronic:
9781862396357
Publication date:
January 01, 2013

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal