The nature and origin of magnetic anomalies over the Gölcük caldera; Isparta; South-Western Turkey

M. N. Dolmaz, E. Oksum, E. Erbek, H. E. Tutunsatar, O. Elitok

Abstract


For the first time; ground magnetic survey was performed which data were inverted by means of total horizontal derivative; horizontal gradient analytic signal; and hyperbolic tilt angle techniques to identify subsurface volcanic structures around Isparta city (South-Western Turkey). Here; Gölcük volcanism took place at the apex of the Isparta Angle at the intersection of the Lycian and Antalya nappes. It initiated between 4.0—4.7 my ago mainly as lava extrusions and ended with phreatoplinian eruptions during Quaternary time. The study area is covered by authochtonous and allochthonous units that are intruded by Pliocene and Quaternary Gölcük volcanics and also overlain by pyroclastic fall and flow deposits. The boundaries were revealed for the buried volcanic structure from the edge detection methods. The geometry of the trachytic dome southwestern of the Gölcük Lake and its downward continuation were studied by 2D modelling with the control of the power spectrum depth results applied to the focused anomaly. The azimuthally-averaged logarithmic power spectra plot indicates that the downward continuation of source depth of the trachytic dome reaches up to 850 m. The forward inversion results indicate that the horizontal size of the model for this trachytic dome is 1250 m beneath the surface while it’s surface extension is only about 400 m.


Keywords


South-Western Turkey; Gölcük Lake crater; volcanism; magnetic anomalies; subsurface volcanic structures

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References


Alici P.; Temel A.; Gourgaud A.; Kieffer G.; Gündogdu M. N.; 1998. Petrology and geochemistry in the Gölcük area (Isparta; SW Turkey): Genesis of enriched alkaline magmas. J. Volcanol. Geoth. Res. 85; 423—446. doi: 10.1016/S0377-0273(98)00065-1.

Altinli E.; 1945. Etude tectonique de la region d’Antalya: Revue de la Faculte´ des Sciences Universite´ d’Istanbul; Istanbul B10; 60—67.

Baranov V.; 1957. A new method for interpretation of aeromagnetic maps: pseudo gravimetric anomalies. Geophysics 22(2); 359—383.

Bournas N.; Baker H. A.; 2001. Interpretation of magnetic anomalies using the horizontal gradient analytic signal. Annals of Geophysics 44(3); 505—526. doi: doi: https://doi.org/10.4401/ag-3572.

Cooper G. R. J.; Cowan D. R.; 2006. Enhancing potential field data using filters based on the local phase. Computer & Geosciences 32; 1585—1591. doi: 10.1016/j.cageo.2006.02.016.

Cordell L.; 1979. Gravimetric expression of graben faulting in Santa Fe country and the Espanola basin; New Mexico. In: R. V. Ingersoll (ed.); Guidebook to Santa Fe country. New Mexico Geol. Sot. Guidebook. 30th Field Conference; P. 59—64.

Dolmaz M. N.; 2007. An aspect of the subsurface structure of the Burdur-Isparta area; SW Anatolia; based on gravity and aeromagnetic data; and some tectonic implications. Earth Planets Space 59; 5—12. https://doi.org/10.1186/BF03352016.

Elitok Ö.; Özgür N.; Drüppel K.; Dilek Y.; Platevoet B.; Guillou H.; Poisson A.; Scaillet S.; Satir M.; Siebel W.; Bardintzeff J.-M.; Deniel C.; Yilmaz K.; 2010. Origin and geodynamic evolution of late Cenozoic potassium-rich volcanism in the Isparta area; southwestern Turkey. International Geology Review 52(4-6); 454—504.

Erbek E.; Dolmaz M. N.; 2014. Geophysical researches (Gravity and Magnetic) of the Erato-sthenes Seamount in the Eastern Mediterranean Sea. Acta Geopyhsica 62(4);762—784.

Kalyoncuoglu U. Y.; Anadolu N. C.; Baykul A.; Erek Y.; 2010. Isparta sehir merkezi yüzey topragindaki radyoaktivite düzeyi. Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi 14(1); 111—119.

Lefevre C.; Bellon H.; Poisson A.; 1983. Pre’sences de leucitites dans le volcanisme Plioce’ne de la region d’Isparta (Taurides occidentales; Turquie). Comptes-Rendus de l’Acade’mie des Sciences 297(2); 367—372.

Platevoet B.; Elitok Ö.; Guillou H.; Bardintzeff J.-M.; Yagmurlu F.; Nomade S.; Poisson A.; Deniel C.; Özgür N.; 2014. Petrology of Quaternary volcanic rocks and related plutonic xenoliths from Gölcük volcano; Isparta Angle; Turkey. Origin and evolution of the high-K alkaline series. Journal of Asian Earth Sciences 92; 53—76. doi: 10.1016/j.jseaes.2014.06.012.

Platevoet B.; Scaillet S.; Guillou H.; Blamart D.; Nomade S.; Massault M.; Poisson A.; Elitok O.; Özgür N.; Yagmurlu F.; Yilmaz K.; 2008. Pleistocene eruptive chronology of the Gölcük volcano; Isparta Angle; Turkey. Quaternaire 19(2); 147—156.

Poisson A.; Wernli R.; Sagular E. K.; Temiz H.; 2003a. New data concerning the age of the Aksu Thrust in the south of the Aksu valley; Isparta Angle (SW Turkey): consequences for the Antalya basin and the Eastern Mediterranean. Geological Journal 38; 311—327. https://doi.org/10.1002/gj.958.

Poisson A.; Yagmurlu F.; Bozcu M.; Sentürk M.; 2003b. New insights on the tectonic setting and evolution around the apex of the Isparta Angle (SW Turkey). Geological Journal 38; 257—282. https://doi.org/10.1002/gj.955.

Schmitt A. K.; Danišík M.; Siebel W.; Elitok Ö.; Chang; Y.-W.; Shen; C.-C.; 2014. Late Pleistocene zircon ages for intracaldera domes at Gölcük (Isparta; Turkey). J. Volcanol. Geoth. Res. 286; 24—29. doi: 10.1016/j.jvolgeores.2014.08.027.

Spector A.; Grant F. S.; 1970. Statistical models for interpreting aeromagnetic data. Geophysics 35; 293—302.

Talwani M.; Heirtzler J. R.; 1964. Computation of magnetic anomalies caused by two-dimensional structures of arbitrary shape. In: Computers in the Mineral Industries. Standford Univ. Publ. Geol. Sci.; P. 464—480.




DOI: https://doi.org/10.24028/gzh.0203-3100.v40i3.2018.137191

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