One-Dimensional Thermal Modeling of the Eastern Pontides Orogenic Belt (NE Turkey)

Abstract

The eastern Pontides orogenic belt is one of the most complex geodynamic settings in the Alpine-Himalayan belt due to the lack of systematical geological and geophysical data. In this study, 1D crustal structure and P-wave velocity distribution obtained from gravity modeling and seismological data in the area has been used for the development of the thermal model of the eastern Pontides orogenic belt. The computed temperature-depth profiles suggest a temperature of 590 ± 60°C at a Moho depth of 35 km indicates the presence of a brittle-ductile transition zone. This temperature value might be related to water in the subducted crust of the Tethys oceanic lithosphere. The Curie temperature depth value of 29 km, which may correspond to the crustal magma chambers, is found 5-7 km below the Moho depth. Surface heat flow density values vary from 66.5 and 104.7 mW m -2 . High mantle heat flow density value of 48 mW m -2 is obtained for the area should be related to melting of the lithospheric mantle caused by upwelling of asthenosphere.

Determination of the Crustal and Thermal Structure of the Erzurum-Horasan-Pasinler Basins (Eastern Türkiye) Using Gravity and Magnetic Data

“…Spectral analysis, a statistical-approaching method, has been widely used in order to determine the depth of anomaly sources (BHATTACHARYA 1965(BHATTACHARYA , 1966SPECTOR and BHATTACHARYA 1966;NAIDU 1970;SPECTOR and GRANT 1970;TREITEL et al 1971;MISHRA and NAIDU 1974;CURTIS and JAIN 1975;CIANCIARA and MARCAK 1976;HAHN et al 1976;BLAKELY 1995;HOFSTETTER et al 2000;MADEN and GELIS¸LI 2001;RI-VERO et al 2002;BÜ YÜ KSARAÇ et al 2005;BANSAL et al 2006;GELIS¸LI and MADEN 2006;BEKTAS¸et al 2007;MADEN 2009;MADEN et al 2009aMADEN et al , b, 2010MADEN et al , 2012a. This method provides a relationship between anomaly spectrums and the depth of sources in the wavenumber domain.…”

“…PAMUKCU et al (2007) evaluated that the Moho depths increase from 38 to 52 km in the Eastern Anatolia region. MADEN et al (2009a) determined the average Moho, Conrad and basement depth of the eastern Pontides as 35.7, 26.5 and 4.6 km, respectively. Also, they showed that the Moho depths fluctuate between 33.9 and 42.6 km, as obtained from the power spectrum method, and increase from 30.1 to 43.8 km, as determined from gravity inversion studies.…”

“…Later, TEZCAN (1995) stated that the heat flow values over the Anatolia should be much higher than those over the Mediterranean and the Black Sea. MADEN (2009MADEN ( , 2010MADEN ( , 2012aMADEN ( , b, 2013 In this study, we used two different methods to calculate the crustal thickness of the region, the power spectrum method and the empirical equation method. In addition, we evaluated the Curie point depth, thermal gradient, and surface heat flow values of the Erzurum-Horasan-Pasinler to propound the thermal structure of the study region.…”

GEOPHYSICAL REGIONAL GRAVITY MAP of TURKEY and ITS GENERAL ASSESSMENT

“…Akçığ (1988) obtained that there had been an approximate crustal thickness of 30 km in the Aegean Sea, and this thickness reached 35-40 km in West Anatolia using the power spectrum. Maden et al (2005) applied experimental relations to gravity data and measured that the crustal thickness in the Anatolia had changed in between 26.4-49.5 km Maden et al (2009), in other studies, measured the maximum crustal thickness of the Eastern Pontides as 43.8 km using back analysis method. Bekler et al (2005) have used in-well explosions in stone quarries as artificial seismic source and measured the crustal thickness in the Central Anatolia as 36-40 km Arslan et al (2010) measured the crustal thickness of Turkey as 31.4 km (shallowest) and as 50 km (deepest) using the gravity data.…”

Two-Dimensional Geothermal Modelling Along the Central Pontides Magmatic Arc: Implications for the Geodynamic Evolution of Northern Turkey

“…Recently, Maden (2009) and Maden (2010Maden ( , 2011 studied the heat flow values for the Central Anatolia region and the Central Pontides. In the Central Pontides, the heat flow values computed from the Curie depth values vary from 94.1 mWm -2 in the south (back arc) to 63.8 mWm -2 in the north (arc), showing that the south of the investigated area has relatively high geothermal potential with respect to the northern part of the region (Maden 2009).…”