Analysis of Sedimentation Cores

The Client

Industrial Sites

The Challenge

Many industrial sites have a history of contamination over many years and spanning multiple companies.  When a contaminant is known to be present, it may be necessary to estimate the approximate year the contamination was released.  This is done by sampling a column vertically into the sediment and then cutting the cores into sections spanning the top to bottom of the sediment for individual analysis.

GEL Labs Services Provided

GEL has developed expertise in analyzing sedimentation cores for principle radionuclides involved in calculation of sedimentation rates.  Gamma spectroscopy is used for determination of cesium 137 which will typically show maximum readings around the above ground weapons testing periods of the late 1950’s and early 1960’s.  Radium 226, lead 210 and polonium 210 are natural isotopes that are detectable in most sediments and can be used to provide an estimated date based on the isotopic concentration and the sample depth in the core.

The Result

GEL techniques accommodate the small sample quantities and high moisture content that are typical of sediment columns.  Our expertise has been developed in academic and engineering settings where accurate core dating assessments were needed.