Rare Earth Elements (REE)
Definition
The lanthanide series (La to Lu) plus yttrium and sometimes scandium. Their relative abundances in a rock or soil are set by igneous or sedimentary processes and are resistant to surface weathering, making REE patterns a stable provenance fingerprint.
- Composition
- Lanthanides (La-Lu) plus yttrium, sometimes scandium
- Stability
- Resistant to surface weathering
- Set by
- Igneous or sedimentary formation processes
- Forensic use
- Provenance fingerprinting of soil or rock
- Measurement
- ICP-MS or ICP-OES
Common questions
Why are REE patterns preferred over major-element analysis for soil provenance work?+
Major elements can be altered by weathering, organic content, or moisture, while REE relative abundances are set during rock formation and stay largely stable afterward, so the pattern is a more reliable long-term fingerprint of the parent material a soil sample came from.
How specific can a REE-based provenance match be?+
REE patterns typically narrow a sample to a geological source region or formation rather than pinpointing an exact location, so they are usually combined with other trace-element and mineralogical data for a stronger provenance conclusion.
Related terms
- Chondrite Normalisation
- The practice of dividing each REE concentration by the concentration of that element in a chondritic meteorite (or another reference material such...
- 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,...
- 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...