| Meghalayan | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chronology | |||||||||||||||
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| Etymology | |||||||||||||||
| Name formality | Formal | ||||||||||||||
| Name ratified | June 14, 2018[2]: 213 | ||||||||||||||
| Usage information | |||||||||||||||
| Celestial body | Earth | ||||||||||||||
| Regional usage | Global (ICS) | ||||||||||||||
| Time scale(s) used | ICS Time Scale | ||||||||||||||
| Definition | |||||||||||||||
| Chronological unit | Age | ||||||||||||||
| Stratigraphic unit | Stage | ||||||||||||||
| Time span formality | Formal | ||||||||||||||
| Lower boundary definition | 4.2-kiloyear event | ||||||||||||||
| Lower boundary GSSP | Mawmluh Cave, Meghalaya, India 25°15′44″N 91°42′54″E / 25.2622°N 91.7150°E | ||||||||||||||
| Lower GSSP ratified | June 14, 2018[2]: 213 | ||||||||||||||
| Upper boundary definition | Ongoing | ||||||||||||||
| Upper boundary GSSP | N/A | ||||||||||||||
| Upper GSSP ratified | N/A | ||||||||||||||
| Part of a series on |
| Human history |
|---|
| ↑ Prehistory (Stone Age) (Pleistocene epoch) |
| ↓ Future |
The Meghalayan age is the name given in 2018, by the International Commission on Stratigraphy, to the current age or latest geologic age – or uppermost stage of the Quaternary. It is also the upper, or latest, of three subdivisions of the Holocene epoch or series. This way of breaking down time is based only on geology; for example, it is unrelated to the three-age system of historical periods into which human development is sometimes divided.[1]
Timeline
[edit]The Meghalayan begins 4,200 years BP (c. 2251 BCE or 7750 HE).[1][2] Helama & Oinonen (2019) dated the start of the Meghalayan to 2190–1990 BCE.[3] The age began with a 200-year drought that impacted human civilizations in the Eastern Mediterranean, Mesopotamia, the Indus Valley and the Yangtze River Valley.[4]
Origins
[edit]This age is named after the Northeast Indian state of Meghalaya, where the stalagmite was found that is used to mark out its years.[5]
The International Commission on Stratigraphy officially ratified this age in June 2018, along with the earlier Greenlandian and Northgrippian ages/stages. Its Global Boundary Stratotype Section and Point (GSSP) is a Krem Mawmluh Cave formation in Meghalaya. Mawmluh cave is one of the longest and deepest caves in India, and conditions there were suitable for preserving chemical signs of the transition in ages. The global auxiliary stratotype is an ice core from Mount Logan in Canada.[2][6]
IUGS geological heritage site
[edit]In respect of the Mawmluh Cave site being the "GSSP of the youngest unit of the geologic time scale associated with dramatic climate changes with implications on human civilisation," the International Union of Geological Sciences (IUGS) included the GSSP of the Meghalayan Stage in the Mawmluh Cave in its assemblage of 100 "geological heritage sites" around the world in a listing published in October 2022.[7] The organisation defines an IUGS Geological Heritage Site as "a key place with geological elements and/or processes of international scientific relevance, used as a reference, and/or with a substantial contribution to the development of geological sciences through history."[8]
See also
[edit]References
[edit]Citations
[edit]- ^ a b c "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. December 2024. Retrieved 23 October 2025.
- ^ a b c d Walker, Mike; Head, Martin J.; Berkelhammer, Max; Björck, Svante; Cheng, Hai; Cwynar, Les; Fisher, David; Gkinis, Vasilios; long, Antony; Lowe, John; Newnham, Rewi; Rasmussen, Sune Olander; Weiss, Harvey (December 2018). "Formal ratification of the subdivision of the Holocene Series/Epoch (Quaternary System/Period): two new Global Boundary Stratotype Sections and Points (GSSPs) and three new stages/subseries" (PDF). Episodes. 41 (4): 213–223. doi:10.18814/epiiugs/2018/018016. eISSN 2586-1298. ISSN 0705-3797. LCCN 78646808. OCLC 4130038. Retrieved 11 October 2025.
- ^ Helama, Samuli; Oinonen, Markku (15 June 2019). "Exact dating of the Meghalayan lower boundary based on high-latitude tree-ring isotope chronology". Quaternary Science Reviews. 214: 178–184. Bibcode:2019QSRv..214..178H. doi:10.1016/j.quascirev.2019.04.013. hdl:10138/330959. ISSN 0277-3791. S2CID 150012152.
- ^ Jonathan Amos (18 July 2018). "Welcome to the Meghalayan Age – a new phase in history". BBC. Retrieved 3 October 2025.
They are calling it the Meghalayan Age, the onset of which was marked by a mega-drought that crushed a number of civilisations worldwide.
- ^ "Collapse of civilizations worldwide defines youngest unit of the Geologic Time Scale". International Commission on Stratigraphy. Archived from the original on 15 July 2018. Retrieved 3 October 2025.
- ^ "Global Boundary Stratotype Section and Points". International Commission on Stratigraphy. Retrieved 3 October 2025.
- ^ International Union of Geological Sciences 2022, p. 72–73.
- ^ International Union of Geological Sciences 2022, p. 3.
Sources
[edit]- The First 100 IUGS Geological Heritage Sites (PDF). Spain: International Union of Geological Sciences. October 2022. ISBN 978-1-7923-9975-6. Retrieved 3 October 2025.
External links
[edit]- Chronostratigraphy benchmarks
- Meghalayan Age in details
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