Distribution of surface heat flow and effects on the subsurface temperatures in the northern part of Thrace Basin, NW Turkey

Geothermal Energy

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Table 1 Thermal and lithological properties of the formations in Thrace Basin

Formation name	λ^a (N/W)	A^b	Lithologic description^c	Ave. percent thickness^d
Ergene	1.5 (est)	0.7	Sandstone + conglomerate	–
Danişmen	3.02 (65/2)	0.8	Shale + siltstone	18 ± 6
Osmancık	3.1 (est)	0.8	Shale + sandstone	9 ± 2
Mezardere	2.86 (54/3)	0.8	Shale + sandstone	20 ± 6
Ceylan	1.76 (73/8)	0.8	Shale	21 ± 8
Ceylan (tuff)	0.95 (38/2)	1.1	Tuff	~ 0
Soğucak	3.4 (est)	0.3	Limestone + shale	3 ± 1
Hamitabat (shallow)	2.42 (55/13)	1.1	Sandstone + shale	29 ± 10
Hamitabat (deep)	2.89 (29/18)	1.1	Sandstone + shale	29 ± 10

^aλ: thermal conductivity (W/m/K); N: number of samples; W: number of wells (Huvaz et al. 2005). “est” means estimated, see the text for details
^bA: heat generation (µW/m³); values based on gamma-ray logs (Coşkun 1997; Coşkun 2000; Siyako and Huvaz 2007; Turgut and Eseller 2000). Values were converted from API to SI units as in Beardsmore and Cull (2001)
^cHuvaz et al. (2005)
^dAverage percent thickness of each formation calculated using well data in Gürgey (2009); see Fig. 1 inset, which is used in Bullard method. See the text for details