Tertiary
Tertiary | ||||||
---|---|---|---|---|---|---|
Chronology | ||||||
| ||||||
Etymology | ||||||
Name formality | Informal | |||||
Usage information | ||||||
Celestial body | Period | |||||
Stratigraphic unit | System | |||||
Time span formality | Informal | |||||
Lower boundary definition | K-Pg extinction event | |||||
Lower boundary GSSP | None | |||||
Lower GSSP ratified | N/A | |||||
Upper boundary definition | Beginning of the Quaternary glaciation | |||||
Upper boundary GSSP | None | |||||
Upper GSSP ratified | N/A |
Tertiary (
Historical use of the term
The term Tertiary was first used by
In the early development of the study of geology, the periods were thought by scriptural geologists to correspond to the Biblical narrative, the rocks of the Tertiary being thought to be associated with the Great Flood.[3]
In 1833,
Although these divisions seemed adequate for the region to which the designations were originally applied (parts of the Alps and plains of Italy), when the same system was later extended to other parts of Europe and to America, it proved to be inapplicable. Therefore, the use of mollusks was abandoned from the definition and the epochs were renamed and redefined.[citation needed]
For much of the time during which the term 'Tertiary' was in formal use, it referred to the span of time between 65 and 1.8 million years ago. The end date of the Cretaceous and the start date of the Quaternary were subsequently redefined at c. 66 and 2.6 million years ago respectively.[citation needed]
Modern equivalents
The Tertiary period lies between the Mesozoic Era and the Quaternary Period, although it is no longer recognized as a formal unit by the International Commission on Stratigraphy.[citation needed]
The span of the Tertiary is subdivided into the Paleocene (66–56 million years BP), the Eocene (56–33.9 million years BP), the Oligocene (33–23.9 million years BP), the Miocene (23–5.3 million years BP) and the Pliocene (5.3–2.6 million years BP), extending to the first stage of the Pleistocene, the Gelasian Stage.[5][6][7][8]
References
- ^ "tertiary [ tur-shee-er-ee, tur-shuh-ree ]". Dictionary.com Unabridged. Retrieved 5 January 2022.
- ^ Dunbar, Carl O. (1964). Historical Geology (2nd ed.). New York, NY: John Wiley & Sons. p. 352.
- ISBN 9780226731056– via Google Books.
- S2CID 44668464.
- ^ Cohen, K. M.; Finney, S.; Gibbard, P. L. (January 2013). "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
- ISBN 978-0-521-78142-8.
- ^ Gradstein, Felix M.; Ogg, James G.; van Kranendonk, Martin. "On the Geologic Time Scale 2008" (PDF). International Commission on Stratigraphy. p. 5. Retrieved 18 December 2013.
- S2CID 129821669.
External links
- Encyclopædia Britannica (11th ed.). 1911. .