Geochemistry of uranium and thorium and natural radioactivity levels of the western Anatolian plutons, Turkey

Papadopoulos A., Altunkaynak Ş., Koroneos A., UNAL A., KAMACI Ö.

MINERALOGY AND PETROLOGY, cilt.111, sa.5, ss.677-691, 2017 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 111 Sayı: 5
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1007/s00710-017-0492-4
  • Dergi Adı: MINERALOGY AND PETROLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.677-691
  • Anahtar Kelimeler: Granite, Uranium, Thorium, REEs, Western Anatolia, MELT PARTITION-COEFFICIENTS, METAMORPHIC CORE COMPLEX, U-SERIES NUCLIDES, GRANITIC-ROCKS, U-238-U-234-TH-230 DISEQUILIBRIA, RADIONUCLIDE MIGRATION, SEDIMENT TRANSPORT, NORTHWEST ANATOLIA, MAGMA GENESIS, 2 KBAR
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

Seventy samples from major plutons (mainly granitic) of Western Anatolia (Turkey) have been analyzed by gamma-ray spectrometry to determine the specific activities of U-238, Ra-226, Th-232 and K-40 (Bq/kg). The natural radioactivity ranged up to 264 Bq/kg for U-238, 229.62 Bq/kg for Ra-226, up to 207.32 Bq/kg for Th-232 and up to 2541.95 Bq/kg for K-40. Any possible relationship between the specific activities of Ra-226, U-238, Th-232 and K-40 and some characteristics of the studied samples (age, rock-type, colour, grain size, occurrence, chemical and mineralogical composition) was investigated. Age, major and trace element geochemistry, color, pluton location and mineralogical composition are likely to affect the concentrations of the measured radionuclides. The range of the Th/U ratio was large (0.003-11.374). The latter, along with Ra-226/U-238 radioactive secular disequilibrium, is also discussed and explained by magmatic processes during differentiation.