Geochemistry and Zircon U-Pb Dates of Felsic-Intermediate Members of the Late Cretaceous Yuksekova Arc Basin: Constraints on the Evolution of the Bitlis-Zagros Branch of Neotethys (Elazig, E Turkey)

2021-08-01
Ural, Melek
Sayıt, Kaan
KORALAY, OSMAN ERSİN
Göncüoğlu, Mehmet Cemal
Show full item record
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
236
views
0
downloads
During the Late Cretaceous in the Eastern Mediterranean, the northern branch of the southern Neotethys was closed by multiple northward subductions. Of these, the most northerly located subduction created the Baskil continental arc at around 82-84 Ma. The more southerly and intra-oceanic subduction, on the other hand, produced an arc-basin system, the Yuksekova Complex, as early as the late Cenomanian-early Turonian. The abundant and relatively well-studied basaltic rocks of this complex were intruded by dykes, sills and small stocks of felsic-intermediate rocks, not previously studied in detail. The intrusives collected from five different localities in the Elazig region of eastern Turkey are all subalkaline, with low Nb/Y values. Most of them have been chemically classified as rhyodacites/dacites, whereas a small number appear to be andesites. In normal mid-ocean-ridge basalt (N-MORB)-normalised plots, the intrusives are characterised by relative enrichments in Th and La over Nb, Zr, Hf, Ti and high field strength elements (HREEs), indicating their derivation from a subduction-modified source. While their relatively high, positive epsilon(Nd)(i) values (+6.4 and +7.2) might suggest a depleted mantle source for their ultimate origin, somewhat radiogenic Pb values indicate a sedimentary contribution to the source of the rocks. The overall geochemical characteristics indicate their generation in an oceanic arc setting. The zircon U-Pb Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data obtained from five felsic-intermediate rock samples yielded intrusion dates of 80-88 Ma. This suggests that the Elazig oceanic arc-related intrusives are slightly younger than those of the Yuksekova arc-basin system, but coeval with the Baskil continental arc. However, the felsic-intermediate intrusives show different geochemical characteristics (oceanic arc-type, with a lack of crustal contamination) to those of the Baskil continental arc. This indicates that these two igneous systems are unrelated and likely developed in different tectonic settings. This, in turn, supports a geodynamic model in which the northern strand of the southern Neotethys was consumed by multiple northward subductions.
https://hdl.handle.net/11511/91947
ACTA GEOLOGICA SINICA-ENGLISH EDITION
Department of Geological Engineering, Article

Suggestions

Geochemistry of mafic rocks of the Karakaya complex, Turkey: evidence for plume-involvement in the Palaeotethyan extensional regime during the Middle and Late Triassic
Sayıt, Kaan; Göncüoğlu, Mehmet Cemal (2009-03-01)
The Karakaya Complex within the Early Mesozoic Cimmerian Orogeny in northern Turkey represents the remnants of the Palaeotethys. It includes slivers and/or mega-blocks of slightly metamorphic basic volcanic rocks associated with fossiliferous sediments as well as hypabyssal and intrusive rocks with basaltic-andesitic to ultramafic compositions. They display two distinct compositional groups; namely alkaline and variably tholeiitic. The alkaline basalt samples are more akin to oceanic-island basalts (OIB) wi...
Microfacies analysis of upper devonian - lower carboniferous shallow water carbonates of the Yilanli formation in Zonguldak area, North Western, Turkey
Ahmed, Nouman; Yılmaz, İsmail Ömer; Department of Geological Engineering (2016)
The Yılanlı Formation of Upper Devonian to Lower Carboniferous succession of the Zonguldak region were measured from Gökgöl section near Zonguldak city, NW Turkey. The studied section dominantly consists of limestone of grey – dark grey color with thin to thick beds of black shale and claystone. A variety of lithofacies identified in the studied section including limestone, dolomite, shale, claystone and mudstone. Nine microfacies are identified as grainstone, packstone, wackstone, mudstone, bindstone, ruds...
Geochemical characteristics of mafic lavas from the Neotethyan ophiolites in western Turkey: implications for heterogeneous source contribution during variable stages of ocean crust generation
ALDANMAZ, ERCAN; Yaliniz, M. K.; GÜÇTEKİN, AYKUT; Göncüoğlu, Mehmet Cemal (2008-01-01)
The Late Triassic to Late Cretaceous age mafic lavas from the Neotethyan suture zone ophiolites in western Turkey exhibit a wide diversity of geochemical signatures, indicating derivation from extremely heterogeneous mantle sources. The rocks as a whole can be divided into three broad subdivisions based on their bulk-rock geochemical characteristics: (1) mid-ocean ridge basalts (MORB) that range in composition from light rare earth element (LREE)-depleted varieties (N-MORB; (La/Sm)(N) < 1) through transitio...
Geological evolution of the Central Pontides
Okay, Aral; Altıner, Demir; Sunal, Gursel; Aygul, Mesut; Akdogan, Remziye; Altıner, Sevinç; Simmons, Mike (2015-10-07)
Before the Late Cretaceous opening of the Black Sea, the Central Pontides constituted part of the southern margin of Laurasia. Two features that distinguish the Central Pontides from the neighbouring Pontide regions are the presence of an extensive Lower Cretaceous submarine turbidite fan (the Cag.layan Formation) in the north, and a huge area of Jurassic-Cretaceous subduction-accretion complexes in the south. The Central Pontides comprise two terranes, the Istanbul Zone in the west and the Sakarya Zone in...
GEOCHEMISTRY AND TECTONIC SIGNIFICANCE OF AUGEN GNEISSES FROM THE SOUTHERN MENDERES MASSIF (WEST TURKEY)
Bozkurt, Erdin; PARK, RG (1995-05-01)
The protoliths of mylonitized augen gneisses exposed in the southern sector of the Menderes Massif (West Turkey) are calc-alkaline, peraluminous, S-type, late- to post-tectonic tourmaline- and garnet-bearing, two-mica leucogranites. They cut and post-date the fabrics of the 'main Menderes metamorphism' which took place between the early Eocene and early Oligocene and intrude metamorphic basement rocks comprising the so-called 'Palaeozoic schist envelope' of the massif. They are themselves cut by an extensiv...
Citation Formats
M. Ural, K. Sayıt, O. E. KORALAY, and M. C. Göncüoğlu, “Geochemistry and Zircon U-Pb Dates of Felsic-Intermediate Members of the Late Cretaceous Yuksekova Arc Basin: Constraints on the Evolution of the Bitlis-Zagros Branch of Neotethys (Elazig, E Turkey),” ACTA GEOLOGICA SINICA-ENGLISH EDITION, vol. 95, no. 4, pp. 1199–1216, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/91947.
METU IIS - Integrated Information Service open@metu.edu.tr