137cs dating sediment
Such approximate ages, however, may still useful in corroborating interpretations made using the trench stratigraphy, or, at sites which have long earthquake recurrence intervals, determining which earthquake event was responsible for a particular bed offset.The UCL Environmental Radiometric Facility is located within the Department of Geography, University College London and uses low-background hyper-pure germanium gamma spectrometers capable of measuring low-level environmental radioactivity.In recent years, much of the coastal area such as Barataria Basin has been deprived of river-borne sediment through natural stream diversion and the construction of water-control embankments.
These timescales are developed by using a known property of radioactive material, the "half-life." The half-life of an isotope is the amount of time it takes for half a given number of radioactive atoms to decay to another element.
The age of the sediment containing a radioactive isotope with a known half-life can be calculated by knowing the original concentration of the isotope and measuring the percentage of the remaining radioactive material.
Cs peaked between 19 as a result of the atmospheric nuclear explosions and later by the 1986 Chernobyl accident.
These events can be identified in sediments where they form distinctive time stratigraphic marker horizons.
Information on subsidence is available from tide gauge measurements but no measurements have been made of sedimentation rates in marshland developed on Recent Mississippi alluvium.