Nature
PUBLISHED
We are now living in a new geological era, according to scientists responsible for standardizing the Geologic Time Scale. After a decade of work, the International Commission on Stratigraphy (ICS) has officially declared the Holocene Epoch, defined as the geological period that's been occurring since the last Ice Age, is now subdivided into three eras.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.The most recent began 4,200 years ago and is what we're living in now. Named the Late Holocene Meghalayan Age, it was discovered by analyzing stalagmites (the pointy things made from calcium salts that rise up from cave floors) found in a cave in northeast India.
What makes the Meghalayan Age special is that its birth coincides with a cultural event sparked by a global climatic event. Dubbed the “4.2 kiloyear climatic event”, this time period has rocked cultures and is evidenced in sediments on all seven continents.
This period started with a 200-year “mega-drought” that disrupted civilizations around the world. At this time, civilizations in Egypt, Greece, Syria, Palestine, Mesopotamia, the Indus Valley, and the Yangtze River Valley had started to settle down and use agricultural practices, according to a statement from Long Beach State University. After the onset of this 200-year climatic event, the societies were forced to migrate worldwide.
The ICS approved the changes after a decade of work, with formal approval granted by the International Union of Geological Sciences (IUGS).
The two other eras – the Middle Holocene Northgrippian Age (8,300 years ago) and the Early Holocene Greenlandian Age (11,700 years ago) – were defined by identifying levels in ice cores extracted in Greenland. Together, the three represent the Holocene Epoch, encompassing the time since the last Ice Age. Both the stalagmites and ice cores are now recognized as international geostandards and have been placed in protected archives for further study.
Such events are characterized in sedimentary strata accumulated over time as sediment types, fossils, and chemical isotopes are contained within them, recording the history of our world and the physical and biological events that shaped them.
