SEDIMENT ACCUMULATION RATE IN THE RED LAKE (ROMANIA) DETERMINED BY Pb-210 AND Cs-137 RADIOISOTOPES

This work presents the first estimates of the Red lake's sedimentation rate. The determination of the sediment accumulation rate was estimated by using two methods of recent sediment dating: the Pb-210 and the Cs-137 method. Both methods are based on using gamma emission radionuclides. The Pb-210 and Cs-137 concentration in the sediment were measured with a gamma spectrometer with a Hp-Ge detector, GMX type. There has been found activities between 41 +/- 7 - 135 +/- 34 Bq/kg for Pb-210 and 3 +/- 0.5 - 1054 +/- 150 Bq/kg for Cs-137 respectively. Using the CIC methods for the calculation of sedimentation rate, we obtained a 1.23 +/- 0.6 cm/year value, which is an average for this lake.