Modeling of Central Anatolian (Ankara and vicinity) Basins with Gravity and Magnetic Methods

Yıl 2019, , 141 - 166, 01.04.2019

Murat Özkaptan

https://doi.org/10.25288/tjb.546581

Öz

Central Anatolian basins, which are boundend by the Pontides in the north and the Kırşehir&Toros tectonic blocks to the south-southeast, geologically important structures in the region with sediment accumulations up to the present day to comprises subduction to collusion process (Senezoyik) in northern segment of the Neotethys Oceanic litosphere beneath to the Pontides. Within the scope of this study, these depositional structures, which are geographically located in Ankara and in the vicinity and classifield as the Kırıkkale-Bala, Alcı-Orhaniye, Haymana and Tüzgölü basins in litreture. Although sedimentary deposition stages, lithological properties and source characteristics show great similarities, they are considered as different basins in terms of their today’s geographical positions. In this study, these basins were examined with gravity and magnetic methods and information about their structures in the depths of the earth were obtained. Especially, the Haymana and Kırıkkale-Bala basins were found to have the thickest sediment depositions in the region (about 8-9 km). The deep structures of the basins were modeled by gravity method and their possible connections with each other were determined. In particular, it has been tried to explain the ongoing debates in the literature that Tuzgölü and Haymana basins were the same sedimentary basin in the past. Within the basin areas, no clear change in gravity data but high positive magnetic anomalies can be associated with the presence of volcanic units (Neogene) near beneath the surface. In addition, important data related to the evolution of tectonic deformation of the İAESZ on these basins have been revealed. The information of the basins with this depth provides new perspective related with the geodynamic evolution of the region, especially

considering the tectonic blocks they surround.

Anahtar Kelimeler

2.5D Modeling, Basin evolution, Cenral Anatolian basins, Gravity, Magnetic

Orta Anadolu (Ankara ve civarı) Havzalarının Gravite & Manyetik Yöntemler ile Modellenmesi

Öz

Orta Anadolu havzaları; kuzeyde Pontidler, güney-güneydoğudan ise Kırşehir ve Toros tektonik bloklarıyla sınırlandırılmıştır. Havzalar, Neotetis Okyanusu’nun kuzey segmentinin Pontidler altına yitim sürecini de (Senozoik) kapsayacak şekilde günümüze kadar tortul birikimleriyle bölgede önemli jeolojik yapılardır. Bu çalışma kapsamında, coğrafik olarak günümüzde Ankara ve yakın civarında yüzlek vermiş bu yapılar, literatürdeki çalışmalar dikkate alındığında; Kırıkkale-Bala, Alcı-Orhaniye, Haymana ve Tuzgölü havzaları olarak isimlendirilmektedir. Tortul birikim evreleri, litolojik yapıları ve oluşum mekanizmaları büyük benzerlikler göstermesine rağmen bugünkü bulundukları coğrafik konumları bakımından farklı havzalar olarak dikkate alınmıştır. Yapılan bu çalışmada, belirtilen bu havzalar gravite ve manyetik yöntemler ile incelenerek, daha derindeki yapıları ile alakalı bilgiler elde edilmiştir. Özellikle Haymana ve Kırıkkale-Bala havzaları, bölgedeki en kalın tortul birikimine (yaklaşık 8-9 km) sahiptirler. Havzaların yeraltındaki yapıları gravite yöntemi ile modellenerek birbirleri ile olan ilişkileri ve bağlantıları ortaya çıkartılmıştır. Özellikle, Tuzgölü ve Haymana havzalarının geçmiş jeolojik dönemlerde tek bir havza olduklarına dair literatürdeki süregelen tartışmalara gravite ve manyetik veriler ile bir açıklama getirilmeye çalışılmıştır. Havza içlerinde, gravite verisinde ani bir değişim gözlenmeyen fakat pozitif manyetik anomali veren alanlar, yüzeye yakın Neojen yaşlı volkanik birimlerin varlığı ile ilişkilendirilmiştir. Ayrıca, bölgeden geçen İzmir-Ankara-Erzincan Kenet Kuşağı’nın yine bu havzalar üzerindeki tektonik deformasyon evrimine ait önemli veriler ortaya konulmuştur. Havzaların bu derinlikle değişim bilgileri, özellikle çevrelendikleri tektonik bloklar dikkate alındığında bölgenin geçirmiş olduğu jeodinamik evrimine yönelik yeni bilgiler sunmaktadır. 

Anahtar Kelimeler

2.5B Modelleme, Gravite, Havza evrimi, Manyetik, Orta Anadolu havzaları

Kaynakça

• Akpınar, Z., Gürsoy, H., Tatar, O., Büyüksaraç, A., Koçbulut, F., Piper, J.D.A., 2016. Geophysical analysis of fault geometry and volcanic activity in the Erzincan Basin, Central Turkey: Complex evolution of a mature pull-apart basin. Journal of Asian Earth Sciences 116, 97–114.
• Alp, H., Vardar, D., Alpar, B., Ustaömer, T., 2018. Seismic evidence for change of the tectonic regime in Messinian, northern Marmara Sea, Turkey. Journal of Asian Earth Sciences 151, 40–53.
• Altıner, D., Koçyiğit, A., Farinacci, A., Nicosia, U.,Conti, M.A., 1991. Jurassic-lower Cretaceous stratigraphy and paleogeographic evolution of the southern part of north-western Anatolia (Turkey). Geologica Romana 27, 13–80.
• Aydemir, A., Ates, A., 2008. Determination of hydrocarbon prospective areas in the Tuzgolu (Saltlake) Basin, central Anatolia, by using geophysical data. Journal of Petroleum Science and Engineering 62, 36–44.
• Bozkurt, E., 2001. Neotectonics of Turkey - a synthesis. Geodinamica Acta 14, 3–30.
• Çemen, I., Göncüoğlu, M.C., Dirik, K., 1999. Structural evolution of the Tuzgölü basin in Central Anatolia, Turkey. The Journal of Geology 107, 693–706.
• Çukur, D., Krastel, S., Schmincke, H.-U., Sumita, M., Çağatay, M.N., Meydan, A.F., Damcı, E., Stockhecke, M., 2014. Seismic stratigraphy of Lake Van, eastern Turkey. Quaternary Science Reviews 104, 63–84. Demir, D., Bilim, F., Aydemir, A., Ates, A., 2012. Modelling of Thrace Basin, NW Turkey using gravity and magnetic anomalies with control of seismic and borehole data. Journal of Petroleum Science and Engineering 86–87, 44–53.
• Dirik, K., Erol, 0., 2003. Tuzgölü ve civarının tektonomorfolojik evrimi Orta Anadolu, Türkiye, Haymana-Tuzgölü-Ulukışla Basenleri Uygulamalı Çalışma (Workshop). T.P.J.D. Bülteni özel sayı, 27–46.
• Dobrin, M.B., Savit, C.H., 1988. Introduction to Geophysical Prospecting, 4th Edition. ed. McGraw Hill Book Co., New York.
• Erler, A., Akıman, O., Unan, C., Dalkılıc, F., Geven, A., Önen, P., 1991. Petrology and geochemistry of the magmatic rocks of the Kırşehir Massif at Kaman (Kırşehir) and Yozgat. Doğa, Turkish Journal of Engineering and Environmental Sciences 15, 76–100.
• Erler, A., Göncüoğlu, M.C., 1996. Geologic and tectonic setting of the Yozgat Batolith, Northern Central Anatolian Crystalline Complex, Turkey. International Geology Review 38, 714–726.
• Göncüoğlu, M.C., 1986. Orta Anadolu Masifinin güney ucundan jeokronolojik yaş bulguları. MTA Bülteni 105/106, 111–124.
• Görür, N., Oktay, F.Y., Seymen, İ., Şengör, A.M.C., 1984. Palaeotectonic evolution of the Tuzgölü basin complex, Central Turkey: sedimentary record of a Neo-Tethyan closure. Geological Society, London, Special Publications 17, 467–482. Gülyüz, E., 2015. Tectone-Stratigraphic and Thermal Evolution of the Haymana Basin, Central Anatolia, Turkey. Middle East Technical University.
• Gülyüz, E., Özkaptan, M., Lefebvre, C., Kaymakci, N., Persano, C., Stuart, F.M., 2014. Tectonostratigraphic evolution and exhumation of the Haymana basin: Unravelling the subduction and collision history of Neotethys in Turkey, in: EGU General Assembly Conference Abstracts. p. 8284.
• Kadıoğlu, Y.K., Dilek, Y., Foland, K. a., 2006. Slab break-off and syncollisional origin of the Late Cretaceous magmatism in the Central Anatolian crystalline complex, Turkey, in: Special Paper 409: Postcollisional Tectonics and Magmatism in the Mediterranean Region and Asia. pp. 381–415. https://doi.org/10.1130/2006.2409(19)
• Kaymakcı, N., Özçelik, Y., White, S.H., Van Dijk, P.M., 2009. Tectono-stratigraphy of the Çankırı Basin: late Cretaceous to early Miocene evolution of the Neotethyan suture zone in Turkey. Geological Society, London, Special Publications 311, 67–106.
• Kearey, P., Brooks, M., Hill, I., 2013. An introduction to geophysical exploration. John Wiley & Sons.
• Ketin, I., 1966. Tectonic units of Anatolia (Asia Minor). Mineral Research Exploration Bulletin 66, 23–34.
• Koçyiğit, A., 1991. An example of an accretionary forearc basin from northern Central Anatolia and its implications for the history of subduction of Neo-Tethys in Turkey. Geological Society of America Bulletin 103, 22–36. Köksal, S., Göncüoğlu, M.C., 1997. Geology of the Idiş Dağı - Avanos area (Nevşehir - Central Anatolia). Mineral Research Exploration Bulletin 119, 41–58.
• Kosaroglu, S., Buyuksarac, A., Aydemir, A., 2016. Modeling of shallow structures in the Cappadocia region using gravity and aeromagnetic anomalies. Journal of Asian Earth Sciences 124, 214–226.
• Lefebvre, C., Meijers, M.J.M., Kaymakcı, N., Peynircioğlu, A., Langereis, C.G., Van Hinsbergen, D.J.J., 2013. Reconstructing the geometry of central Anatolia during the late Cretaceous: Largescale Cenozoic rotations and deformation between the Pontides and Taurides. Earth and Planetary Science Letters 366, 83–98.
• Licht, A., Coster, P., Ocakoğlu, F., Campbell, C., Métais, G., Mulch, A., Taylor, M., Kappelman, J., Christopher Beard, K., 2017. Tectono-stratigraphy of the Orhaniye Basin, Turkey: Implications for collision chronology and Paleogene biogeography of central Anatolia. Journal of Asian Earth Sciences.
• Maus, S., Barckhausen, U., Berkenbosch, H., Bournas, N., Brozena, J., Childers, V., Dostaler, F., Fairhead, J.D., Finn, C., von Frese, R.R.B., Gaina, C., Golynsky, S., Kucks, R., Lühr, H.,Milligan, P., Mogren, S., Müller, R.D., Olesen, O., Pilkington, M., Saltus, R., Schreckenberger, B., Thébault, E., Caratori Tontini, F., n.d. EMAG2: A 2–arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements. Geochemistry, Geophysics, Geosystems 10. Nairn, S.P., Robertson, A.H.F., Ünlügenç, U.C., Tasli, K., İnan, N., 2013. Tectonostratigraphic evolution of the Upper Cretaceous–Cenozoic central Anatolian basins: an integrated study of diachronous ocean basin closure and continental collision. Geological Society, London, Special Publications 372, 343–384. Norman, T., 1973. Late Cretaceous-Early Tertiary sedimentation in Ankara Yahşihan Region. Türkiye Jeoloji Bülteni 16, 42–66.
• Okay, A.I., 2008. Geology of Turkey: a synopsis. Anschnitt 21, 19–42.
• Okay, A.I., 1984. Distribution and characteristics of the northwest Turkish blueschists., Geological Society Special Publication No. 17. In: J.E. Dixon & A.H.F. Robertson (eds.) The Geological Evolution of the Eastern Mediterranean 455–466.
• Okay, A.I., Tüysüz, O., 1999. Tethyan sutures of northern Turkey, in: Durand, B., Jolivet, L., Horvath, F., Séranne, M. (Eds.), The Mediterranean Basins: Tertiary Extension within the Alpine Orogen: Special Publication of the Geological Society of London. pp. 475–515.
• Oruç, B., Sertçelik, İ., Kafadar, Ö., Selim, H.H., 2013. Structural interpretation of the Erzurum Basin, eastern Turkey, using curvature gravity gradient tensor and gravity inversion of basement relief. Journal of Applied Geophysics 88, 105–113.
• Özsayin, E., Dirik, K., 2007. Quaternary Activity of the Cihanbeyli and Yeniceoba Fault Zones: Inonu Eskişehir Fault System, Central Anatolia. Turkish Journal of Earth Sciences 16, 471–492.
• Pourteau, A., Candan, O., Oberhnsli, R., 2010. Highpressure metasediments in central Turkey: Constraints on the Neotethyan closure history. Tectonics 29. Rasmussen, R., Pedersen, L.B., 1979. End Corrections in Potential Field Modeling. Geophysical Prospecting.
• Sandwell, D.T., Smith, W.H.F., 2009. Global marine gravity from retracked Geosat and ERS-1 altimetry: Ridge segmentation versus spreading rate. Journal of Geophysical Research: Solid Earth 114.
• Şengor, A.M.C., Yilmaz, Y., 1981. Tethyan Evolution of Turkey - a Plate Tectonic Approach. Tectonophysics 75, 181–241.
• Talwani, M., Worzel, J.L., Landisman, M., 1959. Rapid gravity computations for two-dimensional bodies with application to the Mendocino submarine fracture zone. Journal of Geophysical Research.
• Ulamiş, K., Kaçka, N.B., Kiliç, R., 2018. Estimation of seismic slope displacements in North Anatolian Fault Zone, Karamürsel (Kocaeli,Turkey). Journal of African Earth Sciences 138, 258–263.
• Ünalan, G., Yüksel, V., Tekeli, T., Gönenç, O., Seyirt, Z., Hüseyin, S., 1976. The stratigraphy and palaeogeographical evolution of the Upper Cretaceous–Lower Tertiary sediments in the Haymana-Polatlı region (SW of Ankara). Türkiye Jeoloji Kurumu Bülteni 19, 159–176.
• Van Hinsbergen, D.J.J., Maffione, M., Plunder, A., Kaymakcı, N., Ganerød, M., Hendriks, B.W.H., Corfu, F., Gürer, D., Gelder, G.I.N.O., Peters, K., 2016. Tectonic evolution and paleogeography of the Kırşehir Block and the Central Anatolian Ophiolites, Turkey. Tectonics 35, 983–1014.