  High-resolution gamma-ray spectrometry was exploited to determine naturally
occurring thorium (Th), uranium (U) and potassium (K) elemental concentrations
in the whole area covered by the Troodos Ophiolite Complex of Cyprus. For that
purpose, a total of 59 samples from surface soils and 10 from the main rock
formations of the region of interest were analysed. Elemental concentrations
were determined for Th (range from 2.5x10^-3 ppm to 2.0 ppm), U (from 8.1x10^-4
ppm to 0.6 ppm), and K (from 1.3x10^-4 % to 1.0 %). The average values (A.M +-
S.D.) derived are (0.24 +- 0.34) ppm, (0.10 +- 0.10) ppm and (0.21 +- 0.24) %,
for Th, U, and K, respectively, in the soils, and (0.52 +- 0.17) ppm, (0.17 +-
0.11) ppm and (0.49 +- 0.87) % in the rocks. From these values, a radioactivity
(radioelement) loss of nearly 50% is estimated in the underlying surface soils
due to bleaching and eluviation during weathering of the rocks. The measured
Th/U ratio exhibits values between 2 and 4, whereas the K/Th ratio is highly
variable ranging between 1.5x10^3 and 3.0x10^4.
