Spatial Distribution of Thorium Concentration in Afyonkarahisar-Sandıklı-Şuhut Region

Öz

Although at least 20 elements are known as natural radioactive, only U (Uranium), Th (Thorium) and K (Potassium) are important elements in nuclear geophysics. Stable nucleus of 232Th is Pb and in this chain there are 10 isotopes. 208Tl decay chain produces characteristic gamma radiation (2.62 MeV). The 232Th concentrations have been measured using portable gamma-ray spectrometer, for about 180 seconds counting times at 1169 points with known geographical coordinates. The variation of eTh concentration has been mapped in Afyonkarahisar district (Sandıklı, Şuhut, Haydarlı). eTh concentration values ranged between 0-80 ppm with different regional lithology. It should be noted that high concentration values were obtained in volcanic rocks and altered volcanic zones

Anahtar Kelimeler

• Gamma-ray spectrometry
• Afyon volcanics
• Thorium
• Concentration
• Alteration

Afyon-Sandıklı-Şuhut Arasındaki Bölgenin Toryum Konsantrasyonunun Alansal Dağılımı

Öz

Doğal radyoaktif element olarak bilinen en az 20 adet element olmasına rağmen, nükleer jeofizikte sadece U (uranyum), Th (toryum) ve K (potasyum) elementleri önemlidir. Radyoaktif 232Th ile başlayan toryum serisi, ortalama 10 bozunum ürününü takiben, radyoaktif 208Tl izotopunun beta bozunumu sonucunda kararlı 208Pb izotopu ile son bulur. 208Tl'in bozunum sürecinde yayınlanan 2.62 MeV enerjili gama ışınları bir gama-ışın spektrometresi ile belirlenebilir. Bu çalışmada portatif bir gama-ışın spektrometresi ile 232Th bozunum serisinin 2.62 MeV enerjili karakteristik gama ışımaları, 3'er dakikalık sayımlarla koordinatları belirlenen 1169 noktada ölçülmüştür. Afyon Merkez, Sandıklı, Şuhut ve Haydarlı arasında kalan alanda eTh konsantrasyon dağılımı haritalanmıştır. Kayaç türlerinin yayılımına bağlı olarak konsantrasyon değerlerinin 0-80 ppm aralığında değiştiği görülmüştür. Yüksek değerlerin volkanik kayaçlar üzerinde özellikle de volkanik kayaçların ayrışmaya uğramış kesimlerinde elde edilmesi dikkat çekicidir.

Anahtar Kelimeler

• Gamma-ışın spektrometresi rağmen
• nükleer jeofizikte sadece U (uranyum)
• Th (toryum) ve K (potasyum)

Kaynakça

1. Aydın, İ., Aydoğan M.S., Oksum E., Koçak A., 2006. An Attempt to Use Aerial Gamma-Ray Spectrometry Results in Petrochemical of the Volcanic and Plutonic Associations of
2. Geophysical Journal International 167, 1044-1052. Anatolia
3. (Turkey). Darnley, A.G., Ford, K.L., 1989. Regional Airborne Gamma-Ray Surveys: a review; in Proceedings of Exploration ’87: Third Decennial Internatioanl Conference on Geophysical and Geochemical Exploration for Minerals and Groundwater, (ed.) G.D. Garland, Ontario Geological Survey, Special Volume 3, p.229-240.
4. Dodd, P.H., Droullard, R.F., Lathan, C.P., 1969. Borehole Logging Methods for Exploration and Evaluation of Uranium Deposits. In Mining and Groundwater Geophysics 1967, (ed.) L.W. Morley, Geological Survey of Canada, Economic Geology Report 26, p.401-415.
5. Ercan, T.; 1986, Orta Anadolu'daki Senozoyik Volkanizma, M.T.A Dergisi,107,119-141, Ankara.
6. Franklin J.M. 1996. Volcanic-Associated Massive Sulphide Base Metals; in Geology of Canadian Mineral Deposit Types, (ed.) O.R. Eckstrand, W.D. Sinclair and R.I. Thorpe; Geological Survey of Canada, Geology of Canada, no.8, p.158-183.
7. Grasty, R.L., Minty, B.R.S., 1995. A Guide to the Technical Specifications for Airborne Gamma Ray Surveys. Australian Geological Survey Organisation, Record 1195/60, 89p.
8. Grasty, R.L., St. John Smith, B. and Minty, B.R.S., 1997. Developments in the Standardization and Analysis of Airborne Gamma Ray Data. Geophysics and Geochemistry at the Millenium, Proceedings of the Fourth Decennial International Conference on Mineral Exploration, Canada, 1100 pages.

9. Hovgaard, J., Grasty, R.L., 1997. Reducing Statistical Noise in Airborne Gamma-Ray Data Through Spectral Component Analysis. Geophysics and Geochemistry at the Millenium, Proceedings of the Fourth Decennial International Conference on Mineral Exploration, Canada, 1100 pages.
10. Inetrnational Atomic Energy Agency, 1991. Airborne Gamma Ray Surveying. Technical Reports Series No.323, Vienna, 97p.
11. Keller, J., 1983. Potassic Lavas in the Orogenic Volcanism of the Mediterrenean Area. Journal of Volcanology and Geothermal Research, 18, p.321- 335.
12. Ketin, İ., 1966. Anadolu’nun Tektonik Birlikleri. MTA Dergisi, 66, s.20-34.
13. Killeen, P.G., 1979. Gamma Ray Spectrometric Methods in Uranium Exploration-Application and Interpretation. In Geophysics and Geochemsitry in the Search for Metallic Ores, (ed.) P.J. Hood Geological Survey of Canada, Economic Geology Report 31, p.163-230.
14. Morley, L.W., 1969. Regional Geophysical Mapping. In Mining and Groundwater Geophysics 1967, edited by L.W. Morley, Geological Survey of Canada, Economic Geology Report 26, p.249-258.
15. Poulsen, K. H., Hannington, M.D., 1996, Volcanic- Associated Massive Sulphide Gold, in Eckstrand, O. R., Sinclair, W. D., and Thorpe, R. I., Geology of Canadian mineral deposit types: Geol. Surv. Can., Geology of Canada, 8, 183–196.
16. Savaşçın, M.Y., Oyman, T., 1998. Tectono-Magmatic Evolution of Alkaline Volcanics at the Kırka-Afyon- Isparta Structral Trend, SW Turkey. Turkish Journal of Earth Sciences, 7, 201-214.
17. Shives, R.B.K., Ford, K.L., Charbonneau, B.W., 1995. Applications
18. Spectrometric/Magnetic/VLF-EM Surveys-Workshop Manual; Geological Survey of canada, open file 3061, 82p. Gamma
19. Ray Shives, R.B.K., Charbonneau, B.W., Ford, K.L., 2000. The Detection of Potassic Alteration by Gamma-Ray Spectrometry- Recognition of alteration related to Mineralization. Geophysics, v.65(6), p.2001-2011.
20. Uyanık, N.A., Akkurt, İ., Uyanık, O., 2010, A ground Radiometric Study of U, Th and K in Isparta(Turkey). Annals of Geophysics, 53, 25-30.
21. Uyanık, N.A., Uyanık, O., Aydın, İ., Gür F., 2012, Natural Radioactivity of Bricks and Brick Material in the Salihli-Turgutlu area of Turkey. Environmental Earth Science, 68, 499-506.
22. Yağmurlu, F., Savaşçın, Y., Ergun, M., 1997. Relation of Alkaline Volcanism and Active Tectonism Within the Evolution of the Isparta Angle, SW Turkey. Journal of Geology, 15, pp. 717-728.
23. Wilford, J. R., Bierwirth, P. N., Craig, M. A., 1997, Application of Airborne Gamma Ray Spectrometry in Soil/Regolith Mapping and Applied Geomorphology: AGSO J.Austral. Geol. Geophys., 17, 201– 216.