Curie Point Depths Based on Spectrum Analysis of Aeromagnetic Data, West Anatolian Extensional Province, Turkey

Abstract

The Curie point depth map of Western Anatolia was constituted from spectral analysis of the aeromagnetic data. The Curie point depth values from 53 overlapping blocks, 90 · 90 km in size, have been estimated from the band-pass filtered data. The slope of the longest wavelength part of the radially averaged log power spectrum divided by the radial frequency produced the depth to the centroid (z 0 ) for the deepest crustal block. The depth to the top (z t ) was obtained by the slope of the second longest wavelength part of the spectrum. From these depths, the Curie point depth was then calculated by using z b ¼ 2z 0 À z t . The Curie point depth estimates for Western Anatolia range between 8.2 and 19.9 km.A corresponding heat-flow map has been constructed from the Curie point depths and thermal conductivity measurements. The boundary between the areas of shallow and deep Curie point depth coincides with an active extensional system which is characterized by a complex cross-cutting horst-graben system. Deepening of Curie point depths (low heat flows) are observed at Hellenic trench axes. The shallow Curie point depths observed in the western part of the study area correspond with recent geological features such as the grabens of the Menderes Massif.

An overview on the main stratigraphic and structural features of a geothermal area: the case of Nazilli-Buharkent section of the Büyük Menderes Graben, SW Turkey

“…South-western Anatolia has experienced a large-scale extension of continental crust owing to the tectonic exhumation of the Menderes Massif during Late OligoceneMiocene first phase of extension, and it lasted during the Quaternary second phase of extension (Bozkurt, 1996(Bozkurt, , 2000Bozkurt & Park, 1997a, Bozkurt & Park, 1999Bozkurt, Park, & Winchester, 1993;Bozkurt & Satır, 2000;Bozkurt, Winchester, & Park, 1995). This is evidenced by: (a) the well-developed graben-horst system and related low-to high-angle normal faults (Bozkurt, 2003(Bozkurt, , 2007Bozkurt & Park,1994;Bozkurt & Rojay, 2005;Emre, 1996;Gürer et al, 2001;Hetzel et al, 1995;Koçyiğit, 2005;Koçyiğit, Yusufoğlu, & Bozkurt, 1999;Seyitoğlu et al, 2002;Sözbilir, 2001;Yılmaz et al, 2000;Yusufoğlu, 1997), (b) the widespread granitic rocks intruded into the Upper Palaeozoic-Mesozoic cover rocks of the Menderes Massif during Late Oligocene-Middle Miocene (Bozkurt, 2004;Bozkurt, Winchester, & Park, 1995;Glodny & Hetzel, 2007;Hetzel & Reischmann, 1996) and (3) the shallow Curie point depths of 8-11.5 km which imply to the crustal extension, thinning of crust (up to 13 km) beneath the cretan trough, the rise of asthenosphere, thermal anomaly and high-heat flow in south-west Anatolia (Dolmaz, Hisarlı, Ustaömer, & Orbay, 2005;Pfister et al, 1997). It has also been reported that there is an approximately 100-km-wide, 350-km-long and approximately E-W-trending L-shaped zone of shallow-Curie points depths of 8-12 km based on the spectral analysis of the aeromagnetic data (Dolmaz, Hisarlı, Ustaömer, & Orbay, 2005).…”

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

“…Maximum and minimum Curie temperature depths were determined as 20-29 km in the eastern Pontides and western Taurus belt and 6-10 km in the Aegean region, respectively. On the other hand, while DOLMAZ et al (2005) estimated the Curie temperature depth between 8.2 and 19.9 km in the western Anatolia range, ATES¸et al (2005) found that the Curie temperature depth vary from 7.9 to 22.6 km in central Anatolia. In the eastern Anatolia region, BEKTASȩ t al., (2007) showed that the Curie temperature depth fluctuated between 12.9 and 22.6 km.…”

“…Studies on the Curie temperature depth have been performed by some researchers (ATES¸et al, 2005;AYDIN et al, 2005;DOLMAZ et al, 2005;MADEN et al, 2009b;MADEN 2009;MADEN 2010) in the eastern, western, central and northern Turkey. AYDIN et al (2005) presented the Curie-point isotherm map of Turkey by using the spectral analysis technique applied to aeromagnetic data.…”

Curie Point Depth from Spectral Analysis of Magnetic Data in the Southeast Tibet

“…In the west part of Anatolian, Turkey, the study on the CPD showed a geothermal anomaly area, which the length is 350 km and the width is 100 km. It is considered that the asthenosphere upwelling caused by the lithosphere extension formed the anomaly area [3]. The CPD in Sinai Peninsula, Egypt showed that seismicity generally occurred in shallow CPD locations and the Suez Bay is developed about the prospect of geothermal resources [4].…”