SCIENCE|natural and applied sciences|earth sciences|geology
- tréimhse gheolaíoch Reference Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- tréimhse Reference Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- period | geological period
- en
- Definition "third largest unit of the geologic time scale and a subdivision of era" Reference "COM-Terminology Coordination, based on:- Wikipedia > Era (geology) (5.6.2020)- Britannica, The Editors of Encyclopaedia. ""era"" (4.3.2024). Encyclopedia Britannica, 11 Apr. 2018."
- Comment "It is the basic unit of the geologic time scale."