Luminescence dating of the barrier spit at Chilika Lake, Orissa, India.
Optically stimulated luminescence dating has been used to investigate the chronological development of the outer barrier spit forming Chilika Lake (Orissa, India), the largest brackish-water lagoon in Asia. Sixteen samples were examined, and these yielded equivalent doses of between 153 +/- 3 mGy and 2.23 +/- 0.07 Gy, corresponding to ages from approximately 40 y at the top of the spit to approximately 300 y at the bottom. The youngest ages are consistent with the age of the overlying vegetation, and modern material taken from the sub-tidal beach gave a dose of 4 +/- 2 mGy (corresponding to an age of 0.7 +/- 0.4 y), confirming that any previous potential luminescence signal in the source sediment is completely set to zero before incorporation into the spit. A clearly defined period of >2.5 m of barrier construction approximately 40 y ago is identified; prior to that the deposition rate was relatively constant for approximately 300 y.
Nordic Laboratory for Luminescence Dating, Aarhus University, Risø National Laboratory, DK 4000 Roskilde, Denmark. andrew.murray@risoe.dk
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Murray
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Mohanti
D000465:Algorithms; D004307:Dose-Response Relationship, Radiation; D019015:Geologic Sediments / Q000032:analysis*; D005844:Geology / Q000379:methods*; D006207:Half-Life; D007194:India; D008422:Materials Testing; D011829:Radiation Dosage; D011868:Radioisotopes / Q000032:analysis*; D013819:Thermoluminescent Dosimetry / Q000379:methods*
D011868:Radioisotopes