tecmapturkey and surroundings

 

The publications are arranged thematically in the following order

(consult the map above for the location of the respective tectonic zone):

 

  TECTONICS OF TURKEY

  General tectonics of Turkey

            Paleotethyan evolution of the eastern Mediterranean

  Neotethyan evolution of the eastern Mediterranean

  Pontides

Sakarya Zone – western part

 - Central Pontides

 - Eastern Pontides

Istanbul Zone

Strandja Massif

 Anatolide-Taurides

Tavsanli Zone

Menderes Massif

Alanya Massif

Bitlis Massif

            Thrace Basin

Neotectonics and Geomorphology

 

HIGH AND ULTRAHIGH PRESSURE METAMORPHIC ROCKS

Ultra-high pressure rocks in China

Blueschists in the Tavşanlı Zone in northwest Turkey

HP/LT rocks from other parts of Turkey

                  Triassic blueschists and eclogites related

The Alanya Massif, Taurides

                  Precambrian kyanite-eclogites, the Bitlis Massif, southeast Anatolia

                  Early Cretaceous blueschists and eclogites, Central Pontides

Rhodopian eclogites, northwest Turkey

Enigmatic blueschists from Thrace

None HP/LT metamorphic rocks  from Turkey

                  Mineralogy

 

 

 

GENERAL TECTONICS OF TURKEY AND THE REGION

 

A generalized account of the Turkish geology (1), Definition of the Istanbul Zone as a distinct tectonic unit (2); unmetamorphosed Tauride sequence northwest of the Menderes Massif: the Bornova Flysch Zone (3); a general synthesis on the post-Permian tectonic evolution of Turkey with special emphasis on the Pontides (4).

1.    Okay, A.I., 2008; Geology of Turkey: A synopsis. Anschnitt, 21, 19-42.

2.     Okay, A.I., 1989, Tectonic units and sutures in the Pontides, northern Turkey.  In:  Tectonic Evolution of the Tethyan Region (ed. A.M.C. Şengör), NATO Advanced ASI Series, Kluwer Academic Publications, Dordrecht, 109-116.

3.     Okay, A.I., Satır, M., Maluski, H., Siyako, M., Monie, P., Metzger, R. & Akyüz S., 1996, Paleo- and Neo-Tethyan events in northwest Turkey: geological and geochronological constraints. in Tectonics of Asia (ed. A. Yin & M. Harrison), Cambridge University Press, 420-441.

4.     Okay, A.I. & Tüysüz, O., 1999, Tethyan sutures of northern Turkey.  In "The Mediterranean Basins: Tertiary extension within the Alpine orogen" (eds. B. Durand, L. Jolivet, F. Horváth and M. Séranne), Geological Society, London, Special Publication 156, 475-515.

5.     Okay A.I., Tansel, İ. & Tüysüz, O., 2001, Obduction, subduction and collision as reflected in the Upper Cretaceous-Lower Eocene sedimentary record of western Turkey.  Geological Magazine, 138, 117-142.

6.     Okay, A.I., Satır, M. & Siebel, W., 2006,  Pre-Alpide orogenic events in the Eastern Mediterranean region.  In: Gee, D.G. & Stephenson, R.A. (eds.),  European Lithosphere Dynamics.  Geological Society, London, Memoirs 32, 389-405.

7.     Stephenson, R., Mart, Y., Okay, A., Robertson, A., Saintot, A., Stovba, S., Khriachtchevskaia, O., 2004, TRANSMED transect VIII: East European Craton, Crimea, Black Sea, Anatolia, Cyprus, levant Sea, Sinai, Red Sea.  In "The TRANSMED Atlas - The Mediterranean Region from crust to mantle" (eds. W. Cavazza, F.M. Roure, W. Spakman, G.M. Stampfli, P.A. Ziegler). Book with CD-ROM, 141 pp., Springer, Heidelberg, Germany.

8.   Okay, A.I. & Nikishin, A.M., 2015, Tectonic evolution of the southern margin of Laurasia in the Black Sea region. International Geology Review, 57, 1051-1076.

9.  Okay, A.I. & Topuz, G., 2017, Variscan orogeny in the Black Sea region. International Journal of Earth Sciences, 106, 569-592.

 

 

 

Paleotethyan evolution of the eastern Mediterranean

1.    Okay, A.I., 2008; Geology of Turkey: A synopsis. Anschnitt, 21, 19-42.

2.     Okay, A.I. & Tüysüz, O., 1999, Tethyan sutures of northern Turkey.  In "The Mediterranean Basins: Tertiary extension within the Alpine orogen" (eds. B. Durand, L. Jolivet, F. Horváth and M. Séranne), Geological Society, London, Special Publication 156, 475-515.

3.      Okay, A.I., Satır, M. & Siebel, W., 2006,  Pre-Alpide orogenic events in the Eastern Mediterranean region.  European Lithosphere Dynamics.  Memoir of the Geological Society London (in press).

4.      Okay, A.I. & Göncüoğlu, M.C., 2004, Karakaya Complex: a review of data and concepts. Turkish Journal of Earth Sciences, 13, 77-95.

5.      Okay, A.I., 2000, Was the Late Triassic orogeny in Turkey caused by the collision of an  oceanic plateau ?  In "Tectonics and Magmatism in Turkey and Surrounding Area" (eds. E. Bozkurt, J.A. Winchester and J.A.D. Piper), Geological Society, London, Special Publication, 173, 25-41.

6.      Okay, A.I., Siyako, M. & Bürkan, K.A., 1991, Geology and tectonic evolution of the Biga Peninsula.  Special Issue on Tectonics, Bulletin of the Technical University of Istanbul, 44, 191-255.

7.      Okay, A.I. & Mostler, H., 1994, Carboniferous and Permian radiolarite blocks from the Karakaya Complex in northwest Turkey.  Turkish Journal of Earth Sciences, 3, 23-28.

8.      Okay, A.I., Satır, M., Maluski, H., Siyako, M., Monie, P., Metzger, R. & Akyüz S., 1996, Paleo- and Neo-Tethyan events in northwest Turkey: geological and geochronological constraints. in Tectonics of Asia (ed. A. Yin & M. Harrison), Cambridge University Press, 420-441.

9.      Leven, E.Ja. & Okay, A.I., 1996, Foraminifera from the exotic Permo-Carboniferous limestone blocks in the Karakaya Complex, northwest Turkey.  Rivista Italiana Paleontologia e Stratigrafia, 102, 139-174.

10.   Okay, A.I. & Monié, P., 1997, Early Mesozoic subduction in the Eastern Mediterranean: Evidence from Triassic eclogite in northwest Turkey.  Geology, 25, 595-598.

11.   Okay, A.I., Monod, O. & Monié, P., 2002, Triassic blueschists and eclogites from northwest Turkey: vestiges of the Paleo-Tethyan subduction.  Lithos, 64, 155-178.

12.     Okay, A.I., Satır, M. & Siebel, W., 2006,  Pre-Alpide orogenic events in the Eastern Mediterranean region.  In: Gee, D.G. & Stephenson, R.A. (eds.),  European Lithosphere Dynamics.  Geological Society, London, Memoirs 32, 389-405.

13.    Okay, A.I., Noble, P.J. & Tekin, U.K.,.2011, Devonian radiolarian ribbon cherts from the Karakaya Complex, northwest Turkey: implications for the Paleo-Tethyan evolution. Comptes Rendus Palevol, 10, 1-10.

14. Topuz, T., Okay, A.I., Schwarz, W.H., Sunal, G., Altherr, R., Kylander-Clark, A.R.C., 2018, A middle Permian ophiolite fragment in Late Triassic greenschist- to blueschist-facies rocks in NW Turkey: An earlier pulse of suprasubduction-zone ophiolite formation in the Tethyan belt. Lithos, 300–301, 121–135.

 

 

Neotethyan evolution of the eastern Mediterranean

1.    Okay, A.I., 2008; Geology of Turkey: A synopsis. Anschnitt, 21, 19-42.

2.      Okay, A.I. & Tüysüz, O., 1999, Tethyan sutures of northern Turkey.  In "The Mediterranean Basins: Tertiary extension within the Alpine orogen" (eds. B. Durand, L. Jolivet, F. Horváth and M. Séranne), Geological Society, London, Special Publication 156, 475-515.

3.      Okay A.I., Tansel, İ. & Tüysüz, O., 2001, Obduction, subduction and collision as reflected in the Upper Cretaceous-Lower Eocene sedimentary record of western Turkey.  Geological Magazine, 138, 117-142.

4.      Okay, A. & Siyako, M., 1993, The revised location of the İzmir-Ankara Suture in the region between Balıkesir and İzmir (in Turkish).  In: Ozan Sungurlu Symposium Proceedings, Tectonics and Hydrocarbon Potential of Anatolia and Surrounding Regions (ed. S. Turgut) , Ankara, 333-355.

5.      Okay, A.I. & Tansel, İ., 1994, New data on the upper age of the Intra-Pontide ocean  from north of Şarköy (Thrace).  Bulletin of the Mineral Research and Exploration, 114, 23-26.

6.      Okay, A.I., Satır, M., Maluski, H., Siyako, M., Monie, P., Metzger, R. & Akyüz S., 1996, Paleo- and Neo-Tethyan events in northwest Turkey: geological and geochronological constraints. in Tectonics of Asia (ed. A. Yin & M. Harrison), Cambridge University Press, 420-441.

7.      Akyüz, S. & Okay, A.I., 1996, A section across a Tethyan suture in northwest Turkey.  International Geological Review, 38, 405-418.

 

 

 

PONTIDES

Most of my regional geological studies have been in the Pontides – the 1500 km long east-west trending mountain belt south of the Black Sea.  Pontides have been divided into three terranes: the Istanbul, Sakarya and Strandja.  The Sakarya terrane includes the Central and Eastern Pontides, which are more of geographic rather than  tectonic terms.  Three general papers on the Pontides are:

 

Okay, A.I., 2008; Geology of Turkey: A synopsis. Anschnitt, 21, 19-42.

Okay, A.I. & Tüysüz, O., 1999, Tethyan sutures of northern Turkey.  In "The Mediterranean Basins: Tertiary extension within the Alpine orogen" (eds. B. Durand, L. Jolivet, F. Horváth and M. Séranne), Geological Society, London, Special Publication 156, 475-515.

Okay, A.I. & Nikishin, A.M., 2015, Tectonic evolution of the southern margin of Laurasia in the Black Sea region. International Geology Review, 57, 1051-1076.

 

Sakarya Zone – western part

The Sakarya Zone, especially the western part, is characterized by voluminous Paleo-Tethyan (Permo-Triassic) subduction-accretion complexes (Karakaya Complex).  For a general review of the Karakaya Complex including a diifferent ideas for its origin see (1).  The Lower Karakaya Complex contains latest Triassic eclogites and blueschists (2 and 3) and Permian ophiolite fragments (13 and 17); metamorphism is mostly Late Triassic but in places extends into the Early-Middle Jurassic (17).  The Upper Karakaya Complex is characterized by numerous Permo-Carboniferous neritic limestone blocks (4, 5), rare blocks of Paleozoic radiolarian chert (6 and 10), in situ uppermost Triassic limestone (7), all with a very low to low grade of metamorphism (9).   Armutlu peninsula in the contact zone between Istanbul and Sakarya zones has a still unresolved complicated geology (11).  The Paleozoic crystalline basement of the Sakarya Zone (16), its Jurassic-Cretaceous (12 and 15) and Eocene (18) sedimentary cover.  Most of the Mesozoic geology of the Ankara region is represented by huge, crustal-scale olistostromes of Late Cretaceous (Coniacian) age (15).

 

1.   Okay, A.I. & Göncüoğlu,M.C., 2004, Karakaya Complex: a review of data and concepts. Turkish Journal of Earth Sciences, 13, 77-95.

2.   Okay, A.I. & Monié, P., 1997, Early Mesozoic subduction in the Eastern Mediterranean: Evidence from Triassic eclogite in northwest Turkey.  Geology, 25, 595-598.

3.   Okay, A.I., Monod, O. & Monié, P., 2002, Triassic blueschists and eclogites from northwest Turkey: vestiges of the Paleo-Tethyan subduction.  Lithos, 64, 155-178.

4.   Leven, E.Ja. & Okay, A.I., 1996, Foraminifera from the exotic Permo-Carboniferous limestone blocks in the Karakaya Complex, northwest Turkey.  Rivista Italiana Paleontologia e Stratigrafia, 102, 139-174.

5.   Okay, A.I., Siyako, M. & Bürkan, K.A., 1991, Geology and tectonic evolution of the Biga Peninsula.  Special Issue on Tectonics, Bulletin of the Technical University of Istanbul, 44, 191-255.

6.   Okay, A.I. & Mostler, H., 1994, Carboniferous and Permian radiolarite blocks from the Karakaya Complex in northwest Turkey.  Turkish Journal of Earth Sciences, 3, 23-28.

7.   Okay, A.I. & Altıner, D., 2004, Uppermost Triassic limestone in the Karakaya Complex - stratigraphic and tectonic significance. Turkish Journal of Earth Sciences, 13, 187-199.

8.   Yıkılmaz, M.B., Okay, A.I. & Tansel, İ., 2002, A pelagic Palaeocene sequence in the Biga Peninsula, northwest Turkey.  Bulletin of the Mineral Research and Exploration, 123/124, 21-26.

9. Federici, I., Cavazza, W., Okay, A.I., Beyssac, O.,  Zattin, M., Corrado, S. & Dellisanti, F. 2010. Thermochronologic evolution of the Permo-Triassic Karakaya subduction-accretion complex from the Biga Peninsula to the Tokat Massif (Anatolia). Turkish Journal of Earth Sciences, 19, 409-429.

10.    Okay, A.I., Noble, P.J. & Tekin, U.K.,.2011, Devonian radiolarian ribbon cherts from the Karakaya Complex, northwest Turkey: implications for the Paleo-Tethyan evolution. Comptes Rendus Palevol, 10, 1-10.

11. Akbayram, K., Okay. A.I. & Satır, M., 2013. Early Cretaceous closure of the Intra-Pontide Ocean in western Pontides (northwestern Turkey). Journal of Geodynamics, 65, 38-55.

12. Okay, A.I., Altıner, D., 2016, Carbonate sedimentation in an active margin: Cretaceous history of the Haymana region, Pontides. International Journal of Earth Sciences, 105, 2013–2030.

13. Topuz, T., Okay, A.I., Schwarz, W.H., Sunal, G., Altherr, R., Kylander-Clark, A.R.C., 2018, A middle Permian ophiolite fragment in Late Triassic greenschist- to blueschist-facies rocks in NW Turkey: An earlier pulse of suprasubduction-zone ophiolite formation in the Tethyan belt. Lithos, 300–301, 121–135.

14. Atasoy, S.G., Altiner, D., Okay, A.I., 2018, Reconstruction of a Late JurassiceEarly Cretaceous carbonate platform margin with composite biostratigraphy and microfacies analysis (western Sakarya Zone, Turkey): Paleogeographic and tectonic implications.  Cretaceous Research, 92, 66-93.

15. Okay, A. I., Altıner, D. & Kylander‐Clark, A. R. C. (2019). Major Late Cretaceous mass flows in central Turkey recording the disruption of the Mesozoic continental margin. Tectonics, 38, 960-989.

16. Topuz, G., Candan, O., Okay, A.I., von Quadt, A., Othman, M., Zack, T. & Wang, J., 2020, Silurian anorogenic basic and acidic magmatism in northwest Turkey: Implications for the opening of the Paleo-Tethys. Lithos, 356-357, article 105302.

17. Okay, A. I., Sunal, G., Sherlock, S., Kylander-Clark, A. R. C., & Özcan, E. (2020). İzmir-Ankara suture as a Triassic to Cretaceous plate boundary—Data from central Anatolia. Tectonics, 38. e2019TC005849.

18. Özcan, E., Hakyemez, A., Çiner, A., Okay, A.I., Soussi, M., Boukhalfa, K. & Yücel, A.O., 2020, A reinterpretation of the age and depositional environment of the Eocene Çayraz Formation (Haymana Basin, Central Turkey) in the light of new planktonic foraminiferal data. Journal of Asian Earth Sciences, 183, article 104304.

 

Sakarya Zone – central part - Central Pontides

A general account of the geology of the Central Pontides (1).  In the south an immense accretionary complex with Jurassic, Lower and Upper Cretaceous (Neo-Tethyan) accretionary complexes (2, 7, 8 and 9).  In the north a preserved segment of a Triassic forearc sequence (6); an interesting case of HT metamorphism at deeper levels of a Jurassic arc (5) and a huge Lower Cretaceous submarine turbidite fan, which extended from Baltica (Ukranian shield) south to the Tethyan trench (4, 10 and 11).

 

1. Okay, A.I., Altıner, D., Sunal, G., Tüysüz, O., Aygül, M., Akdoğan, R., Altıner, S., Simmons, M., 2018, Geological Evolution of the Central Pontides.  In: Simmons, M.D., Tari, G.C. & Okay, A.I. (eds), Petroleum Geology of the Black Sea, Geological Society, London, Special Publications, 464, 33–67.

2. Okay, A.I., Tüysüz, O., Satır, M., Özkan-Altıner, S., Altıner, D., Sherlock, S., & Eren, R.H., 2006, Cretaceous and Triassic subduction-accretion, HP/LT metamorphism and continental growth in the Central Pontides, Turkey.  Geological Society of America Bulletin, 118, 1247-1269.

3. Federici, I., Cavazza, W., Okay, A.I., Beyssac, O.,  Zattin, M., Corrado, S. & Dellisanti, F. 2010. Thermochronologic evolution of the Permo-Triassic Karakaya subduction-accretion complex from the Biga Peninsula to the Tokat Massif (Anatolia). Turkish Journal of Earth Sciences, 19, 409-429.

4. Okay, A.I., Sunal, G., Sherlock, S., Altıner, D., Tüysüz, O., Kylander-Clark, A.R.C. & Aygül, M., 2013, Early Cretaceous sedimentation and orogeny on the active margin of Eurasia: southern Central Pontides, Turkey. Tectonics, 32, 1247-1271.

5. Okay, A.I., Sunal, G., Tüysüz, O., Sherlock, S., Keskin,M. & Kylander-Clark, A.R.C., 2014, Low-pressure - high-temperature metamorphism during extension in a Jurassic magmatic arc, Central Pontides, Turkey. Journal of Metamorphic Geology, 32, 49-69.

6. Okay, A.I., Altıner, D. & Kılıç, A.M., 2015, Triassic limestone, turbidites and serpentinite–the Cimmeride orogeny in the Central Pontides.  Geological Magazine, 152, 460-479.

7. Aygül, M., Okay, A.I., Oberhaensli, R. & Ziemann, M.A., 2015, Thermal structure of low-grade accreted Lower Cretaceous distal turbidites, the Central Pontides, Turkey: insights for tectonic thickening of an accretionary wedge. Turkish Journal of Earth Sciences, 24, 461-474.

8. Aygül, M., Okay, A.I., Oberhänsli, R., Schmidt, A., Sudo, M., 2015, Late Cretaceous infant intra-oceanic arc volcanism, the Central Pontides, Turkey: Petrogenetic and tectonic implications. Journal of Asian Earth Sciences, 111, 312-327.

9. Aygül, M., Okay, A.I., Oberhänsli, R., Sudo, M., 2016, Pre-collisional accretionary growth of the southern Laurasian margin, Central Pontides, Turkey. Tectonophysics, 671, 218–234.

10. Akdoğan, R.. Okay, A.I., Sunal, G., Tari, G., Meinhold, G. & Kylander-Clark, A.R.C., 2017, Provenance of a large Lower Cretaceous turbidite submarine fan on the active Laurasian margin. Journal of Asian Earth Sciences 134, 309–329.

11. Akdoğan, R., Okay, A. I. & Dunkl, I. (2019). Striking variation in the provenance of the Lower and Upper Cretaceous turbidites in the central Pontides (northern Turkey) related to the opening of the Black Sea. Tectonics, 38, 1050-1069.

 

Sakarya Zone – eastern part - Eastern Pontides

One of the best preserved island arcs, a general review of its geology (1, 6), data on its heterogeneous pre-Liassic basement (3-5 and 7). Detrital zircons in Jurassic volcaniclastic rocks revealing Triassic and Jurassic arc magmatism (8.

)

1.   Okay, A.I. & Şahintürk, Ö., 1997 Geology of the Eastern Pontides. In "Regional and Petroleum Geology of the Black Sea and Surrounding Region" (ed. A.G. Robinson), American Association of Petroleum Geologists (AAPG) Memoir No. 68, 291-311.

2.   Okay, A.I., 1984, The geology of the Ağvanis metamorphic rocks and neighbouring formations.  Bulletin of the Mineral Research and Exploration Institute of Turkey, 99/100, 16-36.

3.   Okay, A.I., 1996, Granulite facies gneisses from the Pulur region, Eastern Pontides.  Turkish Journal of Earth Sciences, 5, 55-61.

4.   Okay, A.I. & Leven, E.Ja., 1996, Stratigraphy and paleontology of the Upper Paleozoic sequence in the Pulur (Bayburt) region, Eastern Pontides.  Turkish Journal of Earth Sciences, 5, 145-155.

5.   Okay, A.I., Şahintürk, Ö. & Yakar, H., 1997, Stratigraphy and tectonics of the Pulur (Bayburt) region in the Eastern Pontides. Bulletin of the Mineral Research and Exploration Institute of Turkey, 119,  1-24.

6.   Konak, N., Okay, A.I., Hakyemez, Y., 2009, Tectonics and Stratigraphy of the Eastern Pontides. Field trip guide book, Maden Tetkik ve Arama Genel Müdürlüğü ve TMMOB Jeoloji Mühendisleri Odası, Ankara, ISBN 978-9944-897-83-9, 120 pp.

7.    Topuz, G., Okay, A.I., Altherr, R., Schwarz, W.H., Sunal, G., Altınkaynak, L., 2014, Triassic warm subduction in the northeast Turkey: Evidence from the Ağvanis metamorphic rocks. Island Arc, 23, 181–205.

8. Akdoğan, R.. Okay, A.I., Dunkl, I., 2018, Triassic-Jurassic Arc Magmatism in the Pontides as Revealed by the U-Pb Detrital Zircon Ages in the Jurassic Sandstones, Northeastern Turkey. Turkish Journal of Earth Sciences, 27, 89-109.

9. Özcan, E., van Gorsel, J.T., Sarı, B., Yücel, A.O., Erbay, S. & Okay, A.I., 2019, Primitive Helicorbitoides (Foraminifera) and associated larger benthic foraminifera from the Campanian Tonya Formation, Trabzon, eastern Pontides, NE Turkey. Cretaceous Research, 101, 30-42.

 

 

Istanbul Zone

An exotic continental terane representing a long standing Paleozoic passive continental margin sequence.  A tectonic model for its Late Cretaceous evolution (1); data on its Paleozoic stratigraphy (2 & 5) and its Paleozoic location based on detrital zircon-rutile geochronology from Carboniferous flysch (3); geochronological data on its Pre-Cambrian and Ordovician basement in the Armutlu Peninsula, southeast of Istanbul (4).

 

1.  Okay, A.I., Şengör, A.M.C. & Görür, N., 1994, Kinematic history of the opening of the Black Sea and its effect on the surrounding regions.  Geology, 22, 267-270 .

2. Görür, N., Monod, O., Okay, A.I., Şengör, A.M.C., Tüysüz, O., Yiğitbaş, E., Sakınç, M. & Akkök, R., 1997, Palaeogeographic and tectonic position of the Carboniferous rocks of the western Pontides (Turkey) in the frame of the Variscan belt.  Bulletin de la Société Géologique de France, 168, 197-205.

3. Okay, N., Zack, T., Okay, A.I. & Barth, M. 2011, Sinistral transport along the Trans-European Suture Zone: detrital zircon-rutile geochronology and sandstone petrography from the Carboniferous flysch of the Pontides. Geological Magazine, 148, 380-403.

4.  Özgörüş, Z., & Okay, A.I., 2005, Orientation of the Cretaceous dykes in the Istanbul region: an approach to the Cretaceous stress distribution.  Bulletin of the Mineral Research and Exploration, 130, 17-27.

4. Okay, A.I., Bozkurt, E., Satır, M., Yiğitbaş, E., Crowley, Q.G. & Shang, C.K., 2008, Defining the southern margin of Avalonia in the Pontides: geochronological data from the Late Proterozoic and Ordovician granitoids from NW Turkey. Tectonophysics, 461, 252-264.

5. Okay, A.I., Atakul-Özdemir, A. & Okay, N., 2020, A pelagic Upper Devonian sequence in Sarıyer, Istanbul. Turkish Journal of Earth Sciences, 29, 785-797.

 

Strandja Massif

 Late Hercynian and Late Jurassic-Early Cretaceous deformation and metamorphism in the Balkans.

Okay, A.I., Satır, M., Tüysüz, O., Akyüz, S. & Chen, F., 2001, The tectonics of the Strandja Massif: Variscan and mid-Mesozoic deformation and metamorphism in the northern Aegean.  International Journal of Earth Sciences (Geologische Rundschau), 90, 217-233.

Cattò, S., Cavazza, W., Zattin, M., Okay, A.I., 2018, No significant Alpine-age tectonic overprint of the Cimmerian Strandja Massif (SE Bulgaria and NW Turkey). International Geology Review, 60, 513–529.

 

     Black Sea

An oceanic back-arc basin of Late Cretaceous age with a thick sedimentary cover.

 

Okay, A.I., Şengör, A.M.C. & Görür, N., 1994, Kinematic history of the opening of the Black Sea and its effect on the surrounding regions.  Geology, 22, 267-270.

Nikishin, A.M., Okay, A.I., Tüysüz, O., Demirer, A., Amelin, N. & Petrov, E., 2015, The Black Sea basins structure and history: New model based on new deep penetration regional seismic data. Part 1: Basins structure and fill. Marine and Petroleum Geology, 59, 638-655.

Nikishin, A.M., Okay, A., Tüysüz, O., Demirer, A., Wannier, M., Amelin, N. & Petrov, E., 2015, The Black Sea basins structure and history: New model based on new deep penetration regional seismic data. Part 2: Tectonic history and paleogeography. Marine and Petroleum Geology, 59, 656-670.

Simmons, M.D., Tari, G.C. & Okay, A.I., 2018. Petroleum Geology of the Black Sea: introduction.  In: Simmons, M.D., Tari, G.C. & Okay, A.I. (eds), Petroleum Geology of the Black Sea, Geological Society, London, Special Publications, 464, 1-18.

 

 

ANATOLIDE-TAURIDES

The Anatolide-Taurides comprises the tectonic zones south of the Izmir-Ankara suture.  In general the metamorphic units in the north (Menderes Massif, Tavsanli Zone and the Kirsehir Massif) are called Anatolides, and the sedimentary nappe units in the south the Taurides, although there are several exceptions.

 

Tavsanli Zone

A 250-km-long, Late Cretaceous high pressure metamorphic belt on the northern margin of the Anatolide-Tauride Block representing the subducted northern margin of the continental crust.  A general review of its tectonic setting (1), constraints and ideas on its exhumation (2), Eocene plutonism (3 and 4).

 

1. Okay, A.I., 1984, Distribution and characteristics of the northwest Turkish blueschists.  In: The Geological Evolution of the Eastern Mediterranean (ed. J.E. Dixon & A.H.F. Robertson),  Geological Society Special Publication No. 17, 455-466.

Okay, A.I., 1985, Metamorphic belts in northwest Anatolia (in Turkish). In: Ketin Symposium Book, Publication of the Geological Society of Turkey, Ankara, 83-92.

2. Okay, A.I., Harris, N.B.W. & Kelley, S.P., 1998, Exhumation of blueschists along a Tethyan suture in northwest Turkey.  Tectonophysics, 285, 275-299.

3. Harris, N.B.W., Kelley, S. & Okay, A.I., 1994, Post-collision magmatism and tectonics in northwest Anatolia.  Contributions to Mineralogy and Petrology, 117, 241-252.

4. Okay, A.I. & Satır, M., 2006, Geochronology of Eocene plutonism and metamorphism in northwest Turkey: evidence for a possible magmatic arc.  Geodinamica Acta, 19, 251-266.

5. Okay, A.I. & Whitney, D.L., 2010, Blueschists, ophiolites and suture zones in northwest Turkey.  Field trip guidebook.

6. Plunder, A., Agard, P., Chopin, C. & Okay, A.I., 2013, Geodynamics of the Tavşanlı zone, western Turkey: Insights into subduction/obduction processes. Tectonophysics, 608, 884-903.

7. Plunder, A., Agard, P., Chopin, C., Pourteau, A.  & Okay, A.I., 2015, Accretion, underplating and exhumation along a subduction interface: From subduction initiation to continental subduction (Tavşanlı zone,W. Turkey). Lithos, 226, 233-254.

8. Plunder, A., Agard, P., Chopin, C., Soret, M., Okay, A.I., Whitechurch, H., 2016, Metamorphic sole formation, emplacement and blueschist overprint: early obduction dynamics witnessed by Western Turkey ophiolites. Terra Nova, 28, 329–339.

9. Pagé, L.,Hattori, K., de Hoog, J.C.M. & Okay, A.I., 2016, Halogen (F, Cl, Br, I) behaviour in subducting slabs: A study of lawsonite blueschists in western Turkey. Earth and Planetary Science Letters, 442, 133–142.

 

 

Menderes Massif

A large, well-studied metamorphic complex in the Aegean.  Eocene Barrovian type metamorphism.  Unorthodox ideas on its structure (1 and 2). relationship with the overlying Lycian nappes (3). Support for the recumbent fold structure of the Menderes Massif (5).  Carboniferous metagranites on the northern margin of the Menderes Massif (4).

 

1. Okay, A.I., 2001, Stratigraphic and metamorphic inversions in the central Menderes Massif: a new structural model.  International Journal of Earth Sciences (Geologische Rundschau), 89, 709-727.

2. Okay, A.I., 2002, Reply: Stratigraphic and metamorphic inversions in the central Menderes Massif: a new structural model.  International Journal of Earth Sciences (Geologische Rundschau), 91, 173-178.

3. Okay, A.I., 1989, Geology of the Menderes Massif and the Lycian nappes south of Denizli, western Taurides.  Bulletin of the Mineral Research and Exploration of Turkey, 109, 37-51.

4. Candan, O., Akal, C., Koralay, O.E., Okay, A.I., Oberhänsli, R., Prelević, D., Mertz-Kraus, R., 2016, Carboniferous granites on the northern margin of Gondwana, Anatolide-Tauride Block, Turkey - evidence for southward subduction of Paleotethys. Tectonophysics, 683, 349–366.

5. Gülmez, F., Damcı, E., Ülgen, U.B. & Okay, A.I., 2019, Deep structure of Central Menderes Massif: data from deep geothermal wells. Turkish Journal of Earth Sciences 28, 531-543.

 

 

Bornova Flysch Zone

A 60-km-wide tectonic belt northwest of the Menderes Massif consisting of Mesozoic limestone and ophiolite blocks in a chaotically deformed flysch matrix of latest Cretaceous age.  First definition of the Bornova Flysch Zone (1) and a condensed limestone section extending from Late Triassic (Norian) to Late Cretaceous (Turonian) (2), a general account of the BFZ with many new stratigraphic sections and a revised model (3).

 

1. Okay, A. & Siyako, M., 1993, The revised location of the İzmir-Ankara Suture in the region between Balıkesir and İzmir (in Turkish).  In: Ozan Sungurlu Symposium Proceedings, Tectonics and Hydrocarbon Potential of Anatolia and Surrounding Regions (ed. S. Turgut) , Ankara, 333-355.

2. Okay, A.I. & Altıner, D., 2007, A condensed Mesozoic section in the Bornova Flysch Zone: A fragment of the Anatolide-Tauride carbonate platform.  Turkish Journal of Earth Sciences, 16,  257-279.

3. Okay, A.I., İşintek, İ., Altıner, D., Özkan-Altıner, S., Okay, N., 2012, An olistostrome- mélange belt formed along a major suture: Bornova Flysch Zone, western Turkey.  Tectonophysics, 568-569, 282-295.

 

 

Alanya Massif

A composite metamorphic nappe in the uppermost structural level in the Taurides on the Mediterranean coast.  It consists of three thin but continuous nappes; the middle one is metamorphosed in the eclogite facies.

 

Okay, A.I. & Özgül, N., 1984, HP/LT metamorphism and the structure of the Alanya Massif, Southern Turkey: an allochthonous composite tectonic sheet.  In: The Geological Evolution of the Eastern Mediterranean  (ed. J.E. Dixon & A.H.F. Robertson), Geological Society Special Publication No. 17, 429-439.

Okay. A.I., 1989, An exotic eclogite/blueschist slice in a Barrovian-style metamorphic terrain, Alanya Nappes, southern Turkey. Journal of Petrology, 30, 107-132.

Çetinkaplan, M., Pourteau, A., Candan, O., Koralay, O.E., Oberhänsli, R., Okay, A.I., Chen, F., Kozlu, H. & Şengün, F., 2016, P-T-t evolution of eclogite/blueschist facies metamorphism in Alanya Massif: time and space relations with HP event in Bitlis Massif, Turkey. International Journal of Earth Sciences, 105, 247–281.

 

Bitlis Massif and Southeast Anatolia

Tectonically imbricated metamorphic slices in southeast Anatolia north of the Assyrian suture.  The Bitlis Massif includes both basement slices with kyanite-eclogites and upper crustal slices with greenschist facies metamorphism.   Recent work has shown an Alpine (Late Cretaceous) high pressure - low temperature metamorphism in the Bitlis Massif. A relative recent discovery is the very high temperature granulite facies metaophiolites from below the Bitlis Massif.

 

Okay, A.I., Arman, M.B. & Göncüoğlu, M.C., 1985, Petrology and phase relations of the kyanite-eclogites from eastern Turkey.  Contributions to Mineralogy and Petrology, 91, 196-204.

Oberhänsli, R., Candan, O., Bousquet, R, Rimmele, G., Okay, A. I., Goff, B.J., 2010, Alpine HP evolution of the eastern Bitlis complex, SE Turkey.  In: Sedimentary basin tectonics from the Black Sea and Caucasus to the Arabian Platform (eds. M. Sosson, N. Kaymakçı, R. Stephenson, V. Starostenko, F. Bergerat, Geological Society, London, Special Publication, 340, 461-483.

Oberhänsli, R., Bousquet, R., Candan, O. & Okay, A.I., 2012, Dating subduction events in East Anatolia, Turkey. Turkish Journal of Earth Sciences, 21, 1-17.

Karaoğlan, F., Parlak, O., Robertson, A., Thöni, M., Klötzli, U., Koller, F. & Okay, A.I., 2013, Evidence of Eocene high-temperature metamorphism of ophiolitic rocks and granitoid intrusion related to Neotethyan subduction processes (Doğanşehir area, SE Anatolia). Geological Society, London, Special Publication, 372, 249-272.

 

Thrace Basin

A large hydro-carbon bearing clastic basin of Eocene-Oligocene age northwest of Istanbul. Stratigraphy and geological development of the basin (1, 2, 3, 7, 8, 9, 12, 13 and 16), olistostromal Eocene facies in the southern Thrace basin (4, 7 and 8), tectonic development of the basin (5 and 6), sandstone petrography and provenance (10). Relationship between the Thrace and the Black Sea basins during the early Tertiary (13, 14 and 15).

 

1.  Görür, N. & Okay, A.I., 1996, Fore-arc origin of the Thrace basin, northwest Turkey.  Geologische Rundschau 85, 662-668.

2. Okay, A.I., Siyako, M. & Yurtsever, A., 2007, Lithostratigraphic units in Thrace.  Maden Tetkik ve Arama Genel Müdürlüğü, Ankara (baskıda).

3. Siyako, M., Bürkan, K.A. & Okay, A.I., 1989, Tertiary geology and hydrocarbon potential of the Biga and Gelibolu peninsulas (in Turkish).  Bulletin of the Turkish Association of Petroleum Geologists, 1, 183-199.

4. Okay, A.I. & Tansel, İ., 1994, New data on the upper age of the Intra-Pontide ocean from north of Şarköy (Thrace).  Bulletin of the Mineral Research and Exploration, 114, 23-26.

5. Okay, A.I., Tüysüz, O. & Kaya, Ş., 2004, From transpression to transtension: Changes in morphology and structure around a bend on the North Anatolian Fault in the Marmara region. Tectonophysics, 391, 259-282.

6. Zattin, M., Okay, A.I. & Cavazza, W., 2005.  Fission-track evidence for late Oligocene and mid-Miocene activity along the North Anatolian Fault in south-western Thrace.  Terra Nova, 17,  95-101.

7. Okay; A.I.,  Özcan, E., Cavazza, W., Okay; N. & Less, G. 2010.  Basement types, Lower Eocene series, Upper Eocene olistostromes and the initiation of the southern Thrace Basin, NW Turkey. Turkish Journal of Earth Sciences, 19, 1-25.

8. Özcan, E., Less, G.,  Okay, A.I.,  Báldi-Beke, M., Kollányi, K. &  Yilmaz, İ.Ö. 2010.  Stratigraphy and larger foraminifera of the Eocene shallow-marine and olistostromal units of the southern part of the Thrace Basin, NW Turkey. Turkish Journal of Earth Sciences, 19, 27-77.

9. Less, G., Özcan, E. & Okay, A.I., 2011, Stratigraphy and larger foraminifera of the Middle Eocene to Lower Oligocene shallow-marine units in the northern and eastern parts of the Thrace Basin, NW Turkey. Turkish Journal of Earth Sciences, 20, 793-845.

10. D’Atri, A., Zuffa, G.G., Cavazza, W., Okay, A.I. & Di Vincenzo, G., 2012, Detrital supply from subduction/accretion complexes to the Eocene–Oligocene post-collisional southern Thrace Basin (NW Turkey and NE Greece). Sedimentary Geology, 243-244, 117-129.

11. Okay, A.I. & Özcan, E., 2014, Faulting, basement uplift and carbonate sedimentation: Çatalca region, west of Istanbul.  Field trip guidebook, AAPG International Conference & Exhibition 2014, Istanbul, Turkey, pre-conference field trip – 4, September 13, 2014, Turkish Association of Petroleum Geologists, Ankara, 15 pp.

12. Özcan, E., Okay, A.I., Bürkan, K.A., Yücel, A.O., Özcan, Z., 2018, The Bartonian-Priabonian marine record of the Biga Peninsula, NW Anatolia (Turkey): larger benthic foraminifera, revised stratigraphy and implications for the regional geology. Geologica Acta, 16, 163-187.

13. Okay, A.I., Özcan, E., Hakyemez, A., Siyako, M., Sunal, G., Kylander-Clark, A.R.C., 2019, The Thrace Basin and the Black Sea: the Eocene - Oligocene connection. Geological Magazine, 156, 39-61.

14. Okay, A.I., Simmons, M., Özcan, E., Starkie, S., Bidgood, M. & Kylander-Clark, A.R.C., 2020, Eocene-Oligocene succession at Kıyıköy (Midye) on the Black Sea coast in Thrace. Turkish Journal of Earth Sciences, 29, 139-153.

15. Simmons, M.D., Bidgood, M.D., Connell, P.G., Ćorić, S., Okay, A.I., Shaw, D., Tulan, E., Mayer, J. & Tari, G.C., 2020, Biostratigraphy and palaeoenvironments of the Oligocene succession (Ihsaniye Formation) at Karaburun (NW Turkey). Turkish Journal of Earth Sciences, 29, 28-63.

16. Özcan, E., Özcan, Z., Okay, A.I., Akbayram, K. & Hakyemez, A., 2020, Ypresian-to Lutetian marine record in NW Turkey: a revised biostratigraphy and chronostratigraphy and implications for the Eocene paleogeography. Turkish Journal of Earth Sciences, 29, 1-27.

 

 

Post-collisional metamorphic core complexes, neotectonics and geomorphology

 

 

Uludag Massif

A major Oligocene dextral shear zone in western Anatolia: Eskişehir Fault and the Uludağ Massif – an earlier start for the escape tectonics – Oligocene granites, one is highly sheared.

 Okay, A.I., Satır, M., Zattin, M., Cavazza, W. & Topuz, G., 2008, An Oligocene ductile strike-slip shear zone: Uludağ Massif, northwest Turkey – implications for the escape tectonics. Geological Society of America Bulletin, 120, 893–911.

Topuz, G. & Okay, A.I., 2017, Late Eocene - Early Oligocene two-mica granites in NW Turkey (the Uludağ Massif): Water-fluxed melting products of a mafic metagraywacke. Lithos, 268–271, 334–350.

 

 

Kazdağ Massif

Oligo-Miocene extension of the lower crust of western Anatolia: Kazdağ Massif

Okay, A.I. & Satır, M., 2000, Coeval plutonism and metamorphism in a latest Oligocene metamorphic core complex in northwest Turkey.  Geological Magazine, 137, 495-516.

Cavazza, W., Okay, A.I. & Zattin, M., 2009, Rapid early-middle Miocene exhumation of the Kazdağ metamorphic core complex (Western Anatolia). International Journal of Earth Sciences (Geol Rundsch), 98, 1935–1947.

 

 

North Anatolian Fault

Geometry of the North Anatolian Fault and submarine strike-slip basins in the Marmara Sea (1,2), rearrangment of drainage and morphology through fault activity (3), evidence for earlier fault activity along the North Anatolian Fault (5, 6).

1. Okay, A.I., Demirbağ, E., Kurt, H., Okay, N. & Kuşçu, İ., 1999, An active, deep marine strike-slip basin along the North Anatolian fault in Turkey.  Tectonics, 18, 129-148.

2. Okay, A. I.,  Kaşlılar-Özcan, A., İmren, C., Boztepe-Güney, A., Demirbağ, E. & Kuşçu, İ. 2000, Active faults and evolving strike slip basins in the Marmara Sea, northwest Turkey: a multi-channel seismic reflection study.  Tectonophysics, 321, 189-218.

3. Okay, N. & Okay, A.I., 2002, Tectonically induced Quaternary drainage diversion in northeastern Aegean. Journal of the Geological Society, London, 159, 393-400.

4. Okay, A.I., Tüysüz, O. & Kaya, Ş., 2004, From transpression to transtension: Changes in morphology and structure around a bend on the North Anatolian Fault in the Marmara region. Tectonophysics, 391, 259-282.

5. Zattin, M., Okay, A.I. & Cavazza, W., 2005.  Fission-track evidence for late Oligocene and mid-Miocene activity along the North Anatolian Fault in south-western Thrace.  Terra Nova, 17,  95-101.

6. Janssen, C., Bohnhoff, M., Vapnik, Y., Gorgun, E., Bulut, F., Plessen, B., Pohl, D., Aktar, M., Okay, A.I., Dresen, G., 2009, Tectonic evolution of the Ganos segment of the North Anatolian Fault (NW Turkey).  Journal of Structural Geology, 31, 11-28.

7. Zattin, M., Cavazza, W., Okay, A.I., Federici, I., Fellin, M.G., Pignalosa, A. & Reiners, P. 2010. A precursor of the North Anatolian Fault in the Marmara Sea region. Journal of Asian Earth Sciences, 39, 97–108.

8. Akbayram, K., Sorlien, C. & Okay, A.I., 2016, Evidence for a minimum 52±1 km of total offset along the northern branch of the North Anatolian Fault in northwest Turkey. Tectonophysics, 668-669, 35-41.

 

 

Bitlis collision zone

Apatite fission track data showing Miocene collision between Arabia and Eurasia.

 

Okay, A.I., Zattin, M. & Cavazza, W., 2010, Apatite fission-track data for Miocene Arabia-Eurasia collision. Geology, 38, 35-38.

Albino, I., Cavazza, W., Zattin, M., Okay, A.I., Adamia, S. & Sadradze, N., 2014, Far-field tectonic effects of the Arabia-Eurasia collision and the inception of the North Anatolian Fault system. Geological Magazine, 151, 372–379.

Cavazza, W., Cattò, S., Zattin, M., Okay,A.I. & Reiners, P., 2018, Thermochronology of the Miocene Arabia-Eurasia collision zone of southeastern Turkey: Geosphere, 14, 1–17.

Vincent, S. J., Saintot, A., Mosar, J., Okay, A. I., & Nikishin, A. M., 2018, Comment on “Relict basin closure andcrustal shortening budgets during continental collision: An example from Caucasus sediment provenance” by Cowgill et al. (2016). Tectonics, 37. 2017TC004515.

 

 

Geomorphology

 

An early fluviatile network in the western Taurides (1), a major river diversion in Thrace (2) and when did Anatolia became a land area (3)?

1.  Monod, O., Kuzucuoğlu, C. & Okay, A.I., 2006, A Miocene paleovalley network in the Western Taurus (Turkey).  Turkish Journal of Earth Sciences, 15, 1-23.

2. Okay, N. & Okay, A.I., 2002, Tectonically induced Quaternary drainage diversion in northeastern Aegean. Journal of the Geological Society, London, 159, 393-400.

3. Okay, A. I.,Zattin, M., Özcan, E., & Sunal, G. 2020, Uplift of Anatolia. Turkish Journal of Earth Sciences, 29, 696-713.

 

 

 

HIGH AND ULTRA-HIGH PRESSURE METAMORPHIC ROCKS

Ultra-high pressure rocks in China

Papers on the petrology and tectonics of the worlds largest UHP terrain; the description of the first coesite in garnet and dolomite in Dabie Shan (1,9), tectonic model for exhumation of the UHP metamorphic rocks (3,4), degree of reequilibration within the eclogite facies during exhumation based on a new geobarometer (8).

1. Okay, A.I., Xu Shutong & A.M.C. Şengör, 1989, Coesite from the Dabie Shan eclogites, central China.  European Journal of Mineralogy, 1, 595-598.

2. Xu, S.T., Okay, A.I., Ji, S.Y., Şengör, A.M.C., Su, W., Liu, Y.C. & Jiang, L.L., 1992, Diamond from the Dabie Shan metamorphic rocks and its implication for tectonic setting.  Science, 256, 80-82.

3. Okay, A.I. & Şengör, A.M.C., 1992, Evidence for intracontinental thrust-related exhumation of the ultra-high-pressure rocks in China.  Geology, 20, 411-414.  

4. Okay, A.I., Şengör, A.M.C. &  Satır, M., 1993, Tectonics of an ultra-high pressure metamorphic terrane: the Dabie Shan/Tongbai Shan orogen, China. Tectonics, 12, 1320-1334.

5. Okay, A.I., 1993, Petrology of a diamond and coesite-bearing metamorphic terrain: Dabie Shan, China.  European Journal of Mineralogy , 5, 659-675.

6.  Okay, A.I., 1994, Sapphirine and Ti-clinohumite in ultra-high-pressure garnet-pyroxenite and eclogite from Dabie Shan, China.  Contributions to Mineralogy and Petrology, 116, 145-155.

7. Schertl, H-P. & Okay, A.I., 1994, Coesite inclusion in dolomite in Dabie Shan, China: Petrological and rheological significance.  European Journal of Mineralogy, 6, 995-1000.

8. Okay, A.I., 1995, Paragonite eclogites from Dabie Shan, China: Reequilibration during exhumation ?.  Journal of Metamorphic Geology, 13, 449-460.

 

Blueschists in the Tavsanli Zone in northwest Turkey

       One of the best preserved blueschists belts in the world; no retrogression; very low P/T gradients preserved; a prime example of a subducted continental crust

 

          General introduction and tectonic setting

Okay, A.I., 1989, Alpine-Himalayan blueschists. Annual Reviews of the Earth and Planetary Sciences, 17, 55-87.

Okay, A.I., 1986, High pressure/low temperature metamorphic rocks of Turkey.  In: Blueschists and Eclogites  (ed. B.W. Evans and E.H. Brown), Geological Society of America Memoir No. 164, 333-348.

Okay, A.I., 1984, Distribution and characteristics of the northwest Turkish blueschists.  In: The Geological Evolution of the Eastern Mediterranean (ed. J.E. Dixon & A.H.F. Robertson),  Geological Society Special Publication No. 17, 455-466.

Okay, A.I., 1985, Metamorphic belts in northwest Anatolia (in Turkish). In: Ketin Symposium Book, Publication of the Geological Society of Turkey, Ankara, 83-92.

 

          Petrology and P-T paths

Unique jadeite + chloritoid assemblages in the metapelites indicate one of the highest P/T ratios (24 kbar at 430° ) and lowest geotherms (5° C/km)in the continental crust (papers 4 and 6);  a prograde reaction associated with penetrative strain producing sodic amphibole during subduction (2, 3);  incipient metamorphism and metasomatism in the accretionary complex (3);  first example of partial prograde aragonitization of micritic limestones (7); phonolites in blueschist facies with jadeite-K-feldspar-lawsonite assemblages utilised as jade (5); a jadeite-granitoid of Ordovician age (8).

1. Okay, A.I., 1980.  Mineralogy, petrology and phase relations of glaucophane-lawsonite zone blueschists from the Tavşanlı  region, northwest Turkey.  Contributions to Mineralogy and Petrology, 72, 243-255.

2. Okay, A.I., 1980, Lawsonite zone blueschists and a sodic amphibole producing reaction in the Tavşanlı region, northwest Turkey.  Contributions to Mineralogy and Petrology, 75, 179-186.

3.  Okay, A.I., 1982, Incipient blueschist metamorphism and metasomatism in the Tavşanlı region, northwest Turkey.  Contributions to Mineralogy and Petrology, 79, 361-367.

4. Okay A.I. & Kelley, S.P, 1994, Tectonic setting, petrology and geochronology of jadeite + glaucophane and chloritoid + glaucophane schists from northwest Turkey.  Journal of Metamorphic Geology, 12, 455-466.

5. Okay, A.I., 1997, Jadeite-K-feldspar rocks and jadeitites from northwest Turkey.  Mineralogical Magazine, 61, 835-843.

6. Okay, A.I., 2002, Jadeite-chloritoid-glaucophane-lawsonite schists from northwest Turkey: unusually high P/T ratios in continental crust.  Journal of Metamorphic Geology, 20, 757-768.

7. Topuz, G., Okay, A.I., Altherr, R., Meyer, H.P. & Nasdala, L., 2006, Partial high-pressure aragonitization of micritic limestones in an accretionary complex, Tavşanlı Zone, NW Turkey.  Journal of Metamorphic Geology, 24, 603-613.

8. Okay, A.I., Satır, M. & Shang, C.K., 2008, Ordovician metagranitoid from the Anatolide-Tauride Block, northwest Turkey -geodynamic implications. Terra Nova, 20, 280–288.

9. Topuz, G. & Okay, A.I., 2014, Prograde calcite to aragonite transformation in the Gümüşyeniköy micritic limestones (Tavşanlı, NW Turkey). International Journal of Earth Sciences, 103, 2271–2272.

9. Plunder, A., Agard, P., Chopin, C. & Okay, A.I., 2013, Geodynamics of the Tavşanlı zone, western Turkey: Insights into subduction/obduction processes. Tectonophysics, 608, 884-903.

10. Plunder, A., Agard, P., Chopin, C., Pourteau, A.  & Okay, A.I., 2015, Accretion, underplating and exhumation along a subduction interface: From subduction initiation to continental subduction (Tavşanlı zone,W. Turkey). Lithos, 226, 233-254.

 

 

          Exhumation and associated Eocene magmatism

Constraints on the exhumation of the subducted continental upper crust and a mechanism for exhumation (11);  origin of the Eocene plutons intruding the blueschists and the overlying ophiolites (12, 14).

1.  Okay, A.I., Harris, N.B.W. & Kelley, S.P., 1998, Exhumation of blueschists along a Tethyan suture in northwest Turkey.  Tectonophysics, 285, 275-299.

2. Harris, N.B.W., Kelley, S. & Okay, A.I., 1994, Post-collision magmatism and tectonics in northwest Anatolia.  Contributions to Mineralogy and Petrology, 117, 241-252.

3. Akyüz, H.S. & Okay, A.I., 1999, The geology of the south of Manyas (Balıkesir) and the tectonic significance of blueschists.  Bulletin of the Mineral Research and Exploration, 120, 81-95.

4. Okay, A.I. & Satır, M., 2006, Geochronology of Eocene plutonism and metamorphism in northwest Turkey: evidence for a possible magmatic arc.  Geodinamica Acta, 19, 251-266.

5. Sunal, G., Erturaç, M.K., Topuz, G., Okay, A.I. & Zack, T., 2019, The Early Eocene Ekmekçi Granodiorite porphyry in the Karacabey region (western Sakarya Zone), NW Turkey. Turkish Journal of Earth Sciences, 28, 589-602.

 

          Geochronology

Ar-Ar and Rb-Sr phengite and sodic amphibole data for the Late Cretaceous (80 Ma) HP/LT metamorphism (1, 2); zircon Pb-Pb data on the Triassic and Ordovician protolith ages.

1. Sherlock, S., Kelley, S.P., Inger, S., Harris N. & Okay, A.I., 1999, 40Ar-39Ar and Rb-Sr geochronology of high-pressure metamorphism and exhumation history of the Tavsanli Zone, NW Turkey. Contributions to Mineralogy and Petrology, 137, 46-58.

2. Okay A.I. & Kelley, S.P, 1994, Tectonic setting, petrology and geochronology of jadeite + glaucophane and chloritoid + glaucophane schists from northwest Turkey.  Journal of Metamorphic Geology, 12, 455-466.

3. Okay, A.I., Satır, M. & Shang, C.K., 2008, Ordovician metagranitoid from the Anatolide-Tauride Block, northwest Turkey -geodynamic implications. Terra Nova, 20, 280–288.

 

          Modelling

Bodur, Ö. F., Göğüş, O. H., Pysklywec, R. N., & Okay, A. I. (2018). Mantle lithosphere rheology, vertical tectonics, and the exhumation of (U)HP rocks. Journal of Geophysical Research: Solid Earth, 123, 1824–1839.  

 

HP/LT rocks from other parts of Turkey

Triassic blueschists and eclogites related to the Paleo-Tethyan subduction

Okay, A.I. & Monié, P., 1997, Early Mesozoic subduction in the Eastern Mediterranean: Evidence from Triassic eclogite in northwest Turkey.  Geology, 25, 595-598.

Okay, A.I., Monod, O. & Monié, P., 2002, Triassic blueschists and eclogites from northwest Turkey: vestiges of the Paleo-Tethyan subduction.  Lithos, 64, 155-178.

 

A thin eclogite nappe in the Alanya Massif, Taurides

Okay, A.I. & Özgül, N., 1984, HP/LT metamorphism and the structure of the Alanya Massif, Southern Turkey: an allochthonous composite tectonic sheet.  In: The Geological Evolution of the Eastern Mediterranean  (ed. J.E. Dixon & A.H.F. Robertson), Geological Society Special Publication No. 17, 429-439.

Okay. A.I., 1989, An exotic eclogite/blueschist slice in a Barrovian-style metamorphic terrain, Alanya Nappes, southern Turkey. Journal of Petrology, 30, 107-132.

Çetinkaplan, M., Pourteau, A., Candan, O., Koralay, O.E., Oberhänsli, R., Okay, A.I., Chen, F., Kozlu, H. & Şengün, F., 2016, P-T-t evolution of eclogite/blueschist facies metamorphism in Alanya Massif: time and space relations with HP event in Bitlis Massif, Turkey. International Journal of Earth Sciences, 105, 247–281.

 

Precambrian kyanite-eclogites from the Bitlis Massif, southeast Anatolia

Okay, A.I., Arman, M.B. & Göncüoğlu, M.C., 1985, Petrology and phase relations of the kyanite-eclogites from eastern Turkey.  Contributions to Mineralogy and Petrology, 91, 196-204.

 

Early Cretaceous blueschists and eclogites from the central Pontides

Okay, A.I., Tüysüz, O., Satır, M., Özkan-Altıner, S., Altıner, D., Sherlock, S., & Eren, R.H., 2006, Cretaceous and Triassic subduction-accretion, HP/LT metamorphism and continental growth in the Central Pontides, Turkey.  Geological Society of America Bulletin, 118, 1247-1269.

 

 

Rhodopian eclogites from northwest Turkey

Okay, A.I. & Satır, M., 2000, Coeval plutonism and metamorphism in a latest Oligocene metamorphic core complex in northwest Turkey.  Geological Magazine, 137, 495-516.

Okay, A.I. & Satır, M., 2000, Upper Cretaceous eclogite facies metamorphic rocks from the Biga Peninsula, northwest Turkey.  Turkish Journal of Earth Sciences, 9, 47-56.

 

Enigmatic blueschists from Thrace

Şentürk, K. & Okay, A.I., 1984, Blueschists discovered east of Saros Bay in Thrace.  Bulletin of the Mineral Research  and Exploration Institute of Turkey, 97/98, 72-75.

Topuz, G., Okay, A.I., Altherr, R., Satir, M., Schwarz, W.H., 2008, Late Cretaceous blueschist-facies metamorphism in southeastern Thrace (Turkey) and its geodynamic implications. Journal of Metamorphic Geology, 26, 895–913.

 

 

None HP/LT metamorphic rocks from Turkey

Okay, A.I., 1984, The geology of the Ağvanis metamorphic rocks and neighbouring formations.  Bulletin of the Mineral Research and Exploration Institute of Turkey, 99/100, 16-36.

Okay, A.I., 1996, Granulite facies gneisses from the Pulur region, Eastern Pontides.  Turkish Journal of Earth Sciences, 5, 55-61.

Okay, A.I. & Satır, M., 2000, Coeval plutonism and metamorphism in a latest Oligocene metamorphic core complex in northwest Turkey.  Geological Magazine, 137, 495-516.

 

 

Mineralogy

A novel method of estimating oxygen fugacities (partial pressures) in sodic amphibole bearing rocks (3,4); changes in the composition of sodic pyroxenes with increasing grade (1), lawsonite, a major blueschist mineral – its importance (6) and composition (5).

1. Okay, A.I., 1978. Sodic pyroxenes from metabasites in the eastern Mediterranean.  Contributions to Mineralogy and Petrology, 68, 7-11.

2. Carpenter, M.A. & Okay, A.I., 1978.  Topotactic replacement of augite by omphacite in a blueschist rock from northwest Turkey.  Mineralogical Magazine, 42, 435-438.  

3. Okay. A.I., 1980, Sodic amphiboles as oxygen fugacity indicators in metamorphism. Journal of Geology, 88, 225-232.

4. Okay, A.I., 1987, The oxygen fugacity stability of deerite: an alternative view. Journal of Metamorphic Geology, 5, 553-555.

5. Sherlock, S.C. & Okay, A.I., 1999, Oscillatory zoned chrome lawsonite in the Tavsanli Zone, northwest Turkey.  Mineralogical Magazine, 63, 687-692.

6. Whitney, D.L., Fornash, K.F., Kang, P., Ghent, E.D., Martin, L., Okay, A.I. & Brovarone, A.V., 2020, Lawsonite composition and zoning as tracers of subduction processes: a global review. Lithos, 370–371, article 105636.

 

 

Misc

Gökçeoğlu, C., Okay, A.I. & Sezer, E., 2008, International earth science literature from Turkey – 1970-2005: trends and possible causes. Scientometrics, 74, 409-423.