Search SEDIS
| Data sets | Publications | Expeditions | Thesaurus | 
| He/He  | |
|---|---|
| RT | absolute age | 
| helium | |
| isotope ratios | |
| thermochronology | |
| SN | Isotopic ratio used in age determination. Before 1989, also search He-4/He-3. Added to Thesaurus in 1989. | 
| Data sets | Publications | Expeditions | Thesaurus | 
| He/He  | |
|---|---|
| RT | absolute age | 
| helium | |
| isotope ratios | |
| thermochronology | |
| SN | Isotopic ratio used in age determination. Before 1989, also search He-4/He-3. Added to Thesaurus in 1989. |