Chondrite Normalisation
Definition
The practice of dividing each REE concentration by the concentration of that element in a chondritic meteorite (or another reference material such as PAAS), so that a flat normalised pattern indicates an unfractionated REE signature and deviations indicate geological processes.
- Method
- Divide each REE by chondrite reference value
- Alternative reference
- PAAS
- Flat pattern means
- Unfractionated REE signature
- Use
- Trace-element provenance interpretation
Common questions
Why normalise rare earth element data to a chondrite reference at all?+
Raw REE concentrations vary enormously by even-odd atomic number due to nuclear stability effects, producing a sawtooth pattern that obscures geological trends. Dividing by a chondrite reference removes that natural sawtooth and reveals meaningful deviations caused by geological or environmental processes.
How is a chondrite-normalised REE pattern used in forensic trace-evidence work?+
A sample's normalised REE pattern, such as a soil, glass, or mineral fragment, can be compared against a suspected source location's pattern, since geological processes at a given site tend to imprint a distinctive, reproducible REE fractionation signature.
Related terms
- ICP-MS
- Inductively coupled plasma mass spectrometry: the laboratory reference method for trace element quantification in food matrices. Uses high-temperature argon plasma to atomise...
- ICP-OES
- Inductively coupled plasma optical emission spectrometry: the plasma excites atoms which emit element-specific wavelengths of light on returning to ground state; suited...
- LA-ICP-MS
- Laser ablation inductively coupled plasma mass spectrometry; a technique that fires a laser pulse at a sample surface, vaporises a tiny amount,...
- Rare Earth Elements (REE)
- The lanthanide series (La to Lu) plus yttrium and sometimes scandium. Their relative abundances in a rock or soil are set by...
- Spectral Interference
- In ICP-MS, an overlap between the mass of the target analyte and that of a polyatomic or isobaric ion from another element...