Thermoluminescence dating of ocean sediments

1980 ◽  
Vol 17 (3) ◽  
pp. 348-360 ◽  
Author(s):  
A. G. Wintle ◽  
D. J. Huntley
Keyword(s):  
Water Content ◽  
Gamma Dose ◽  
Residual Value ◽  
Dose Rates ◽  
Thermoluminescence Dating

We describe data on the thermoluminescence (TL) of ocean sediments which leads us to propose that exposure to sunlight prior to deposition reduces any previously acquired TL to a small "residual" value. Subsequent radiation from radionuclides in the sediment increases the TL and this increase is used for dating. Three methods of separating these two TL components are described. In the preferred one the reduction in TL (R) caused by a standard sunlamp exposure is measured as a function of an administered gamma dose; extrapolation to R = 0 yields the natural dose.An equation relating this dose to the age and to dose rates derived from radioactivity analyses is presented. The details are given for six samples from each of two cores and their TL ages calculated; these range from 9–140 ka. For one core independent dates from Cycladophora davisiana variations and an 18O/16O stratigraphic marker were available for comparison; the agreement is satisfactory. The TL age uncertainty is primarily set by the uncertainty in the water content.

scholarly journals Temporal changes in gamma dose rates in the Esk Estuary, UK

2011 ◽  
Vol 46 (6) ◽  
pp. S301-S307 ◽  
Author(s):  
M.D. Wood ◽  
D. Copplestone
Keyword(s):  
Temporal Changes ◽  
Gamma Dose ◽  
Dose Rates ◽  
Gamma Dose Rates

Assessment of gamma dose rates from terrestrial exposure in Serbia and Montenegro

2006 ◽  
Vol 121 (3) ◽  
pp. 297-302 ◽  
Author(s):  
S. Dragović ◽  
Lj. Janković ◽  
A. Onjia
Keyword(s):  
Gamma Dose ◽  
Serbia And Montenegro ◽  
Dose Rates ◽  
Gamma Dose Rates

scholarly journals Evaluation of environmental natural radioactivity levels in soil and ground water of Barkin Ladi, Plateau state, Nigeria

2018 ◽  
Vol 14 (3) ◽  
pp. 338-342
Author(s):  
Habu Tela Abba ◽  
Wan Muhammad Saridan Wan Hassan ◽  
Muneer Aziz saleh
Keyword(s):  
Effective Dose ◽  
Groundwater Resources ◽  
Mean Value ◽  
Gamma Dose ◽  
Chemical Toxicity ◽  
Mean Values ◽  
Dose Rates ◽  
Plasma Mass Spectrometry ◽  
Plateau State ◽  
Geochemical Investigation

Gamma spectrometry was used to measure gamma dose rate in air and to determine the activity concentration of naturally occurring radionuclides viz. 226Ra 232Th and 40K in soil samples collected across the geological formations of Barkin Ladi. Dose rates measured in-situ ranged from 5 nGy h−1 to 1265 nGy h−1 with a mean value of 325 nGy h−1. The activity concentrations of 226Ra ranged from 27 to 327 Bq kg−1, 34 to 457 Bq kg−1 for 232Th and 43 to 1055 Bq kg−1 for 40K. Their mean values are significantly higher than their corresponding global average values. Annual effective dose due to exposure to gamma dose is calculated at 0.34 mSv y−1. Mass concentrations of uranium (238U) and thorium (232Th) determined in groundwater samples using Inductive Coupled Plasma Mass Spectrometry (ICP-MS) ranged from 2.5 to 35 µg l−1 for 238U and 0.5 to 15 µg l−1 for 232Th. Ingestion effective dose varies between 10.5 and 142 mSv y−1 for 238U and between 0.34 and 10.2 mSv y−1 for 232Th. Mass concentration of three water samples exceed the toxicity limit of U in groundwater provided by WHO. The result revealed that human risk due to ingestion of groundwater is from chemical toxicity rather than radiological effects.  The results of this work will be useful for radio-geochemical investigation and groundwater resources management.

scholarly journals Assessment of radiological risk in the area around surface disposal at Al -Tuwaitha site

2019 ◽  
Vol 14 (30) ◽  
pp. 90-97
Author(s):  
Asia H. Al-Mashhadani
Keyword(s):  
Health Risk ◽  
Hpge Detector ◽  
Specific Activity ◽  
Gamma Dose ◽  
Dose Equivalent ◽  
Radiological Risk ◽  
Dose Rates ◽  
Gamma Dose Rates ◽  
Specific Activities

The gamma dose rates and specific activity of 137Cs, 60Co and 40K insamples of soil taken from places near the landfill radiation at Al-Tuwaitha site were measured using a portable NaI(Tl) detector. Theresults of gamma dose rates in samples were ranged from 52.6nGy.h-1 to 131nGy.h-1. Then the specific activity of 137Cs, 60Co and40K in soil were determined using high pure germanium (HPGe)detector. The specific activities were varied from 1.9 to 115500 Bq.kg-1 for 137Cs, from 6.37 to 616.5 Bq. kg-1 for 60Co, and from 3 to839.5 Bq. kg-1 for 40K. The corresponding health risk for the annualeffective dose equivalent varied from 1.85×10-14 to 15.7mSv/y. Theresults were compared with various international recommendations.

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