Timing of post-collisional H-type to A-type granitic magmatism: U-Pb titanite ages from the Alpine central Anatolian granitoids (Turkey)

Date

2004-12-01

Author

Koksal, S
Romer, RL
Göncüoğlu, Mehmet Cemal
Toksoy Köksal, Fatma

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

193
views

0
downloads

The last stages of the continental collision during the closure of the Neotethyan ocean in central Anatolia are characterized by post-collisional H- and A-type granitoids intruding both the metamorphic country rocks and allochthonous ophiolitic rocks of the central Anatolian crystalline complex. Available Rb - Sr and K - Ar whole-rock and mineral age data on the Hand A-type granitoids in central Anatolia are inconsistent. To better constrain the geological relevance and the timing of the change in the chemical character of magmatism in the wake of the Alpine orogeny in Anatolia, we re-evaluated the geochemical characteristics and dated titanite from representative H- (Baranadag quartzmonzonite: BR) and A-type ( C, amsari quartz-syenite: CS) granitoids by the U - Pb method. BR is a high-K calc-alkaline intrusion with mafic microgranular enclaves and shows enrichment of LILE relative to HFSE. The alkaline CS displays higher SiO2, Na2O+ K2O, Fe/ Mg, Rb, Th and HFSE with corresponding depletion in CaO, MgO, Fe2O3tot, P2O5, Ba, Sr, and Ti. Chondrite-normalized REE patterns of the BR and CS samples have LREE-enriched and flat HREE patterns, whereas CS differs from BR by higher LREE enrichment and lower MREE and HREE contents. Mineralogical and geochemical characteristics suggest that BR and CS were not products of the same magma source. BR was derived from a subduction-modified depleted hybrid-source and CS had an enriched mantle source with significant crustal contribution. The U - Pb titanite ages of the H-type central Anatolian granitoids ( BR) and the A-type granitoids ( CS) are 74.0 +/- 2.8 and 74.1 +/- 0.7 Ma, respectively. The coeval evolution of post-collisional/ calc-alkaline H- to A-type magmatism was possibly associated with source heterogeneity and variable involvement of continental materials during the evolution of these granitoids. These new age data constrain the timing of the onset of a post-collision extensional period following the Alpine thickening within the passive margin of the Tauride - Anatolide platform, which occurred before the opening of the latest Cretaceous central Anatolian basins.

Subject Keywords

U-Pb titanite age, H-type; A-type, Granitoid, Central Anatolia

URI

https://hdl.handle.net/11511/30867

Journal

INTERNATIONAL JOURNAL OF EARTH SCIENCES

DOI

https://doi.org/10.1007/s00531-004-0432-5

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Timing of depositional regime changes during the Late Cretaceous evolution of the Southern Pontides (Ankara, Central Anatolia, Turkey) Sariaslan, Nisan; Altıner, Sevinç; Altıner, Demir (Elsevier BV, 2020-08-01) During the Cretaceous, vast amounts of marine sediments were deposited along the south-facing active margin of the Eurasia. A stratigraphic section of 91 m was analyzed for planktonic foraminifera (75 samples), with the aim of establishing a refined biostratigraphy of Cenomanian-Campanian deposits in Central Anatolia. A biostratigraphic framework comprising nine biozones was established. In ascending order, the Rotalipora cushmani, Whiteinella archaeocretacea and Helvetoglobotruncana helvetica zones were de...
Reconstruction of a Late Jurassic-Early Cretaceous carbonate platform margin with composite biostratigraphy and microfacies analysis (western Sakarya Zone, Turkey): Paleogeographic and tectonic implications Atasoy, Serdar Görkem; Altıner, Demir (Elsevier BV, 2018-12-01) During Late Jurassic-Early Cretaceous the Pontides were the site of a wide carbonate platform facing the Tethys ocean in the south. In the western Pontides the Upper Jurassic-Lower Cretaceous shallow marine carbonates abut the Tethyan Izmir-Ankara suture with no evidence for platform margin deposits. The Sivrihisar klippe 50 km south of the Izmir-Ankara suture preserves a record of the missing platform margin. In the Upper Jurassic-Lower Cretaceous carbonates exposed in this Sivrihisar klippe, two coeval bu...
Structure of the crust and African slab beneath the central Anatolian plateau from receiver functions: New insights on isostatic compensation and slab dynamics Abgarmi, Bizhan; Delph, Jonathan R.; Özacar, Atilla Arda; Beck, Susan L.; Zandt, George; Sandvol, Eric; TÜRKELLİ, NİYAZİ; Biryol, C. Berk (Geological Society of America, 2017-11-01) The central Anatolian plateau in Turkey is a region with a long history of subduction, continental collision, accretion of continental fragments, and slab tearing and/or breakoff and tectonic escape. Central Anatolia is currently characterized as a nascent plateau with widespread Neogene volcanism and predominantly transtensional deformation. To elucidate the present-day crustal and upper mantle structure of this region, teleseismic receiver functions were calculated from 500 seismic events recorded on 92 t...
Late Holocene deep-sea benthic foraminifera from the Sea of Marmara Alavi, Seyed Naeim (Elsevier BV, 1988-10) The benthic foraminiferal assemblages of two cores from the late-Holocene, organic-carbon-rich and carbonate-poor, deep-sea sediments of the eastern depression of the Sea of Marmara have been studied. They were deposited under high level of primary productivity and poorly oxygenated bottom-water conditions; they show low diversity and are dominated by a group of species adapted to an infaunal life style with wide bathymetric distribution (ca. 70–2000 m) in the Mediterranean Sea. Oxygen deficiency down to ab...
Dating of the Black Sea Basin: new nannoplankton ages from its inverted margin in the Central Pontides (Turkey) Hippolyte, J. -C.; Mueller, C.; Kaymakcı, Nuretdin; SANĞU, ERCAN (Geological Society of London, 2010-01-01) The Eocene uplift and inversion of a part of the Black Sea margin in the Central Pontides, allows us to study the stratigraphic sequence of the Western Black Sea Basin (WBS). The revision of this sequence, with 164 nannoplankton ages, indicates that subsidence and rifting started in the Upper Barremian and accelerated during the Aptian. The rifting of the western Black Sea Basin lasted about 40 Ma (from late Barremian to Coniacian). In the inner, inverted, Black Sea margin, the syn-rift sequence ends up wit...

Citation Formats

S. Koksal, R. Romer, M. C. Göncüoğlu, and F. Toksoy Köksal, “Timing of post-collisional H-type to A-type granitic magmatism: U-Pb titanite ages from the Alpine central Anatolian granitoids (Turkey),” INTERNATIONAL JOURNAL OF EARTH SCIENCES, pp. 974–989, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30867.