Geography
Meghalayan Age — A New Phase in History
- 20 Jul 2018
- 4 min read
Recently, Geologists have ratified a new unit of the Geologic Time Scale, known as the
- The Holocene Epoch reflects everything that has happened over the past 11,700 years –when warming started after the last ice age.
- Therefore, we are currently in the Holocene Epoch,
Meghalayan Age.
Meghalayan Age
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Mawmluh Cave
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- The
Meghalayan , which runs from 4,200 years ago to the present, experienced an abrupt mega-drought and cooling around the globe. - It is the youngest stage of the Holocene Epoch.
- The
Meghalayan Age is unique among the many intervals of the Geologic Time Scale in that its beginning coincides with a cultural event produced by a global climatic event. - After collecting sediments from a stalagmite from the Mawmluh cave in Meghalaya, the smallest climatic event in Earth’s history was defined.
Classification
- Geologists divide the 4.6-billion-year existence of Earth into slices of time such as Eon, Era, System/Period, Series/Epoch, and Stage/Age.
Eons are divided into Eras, Eras into Periods, Periods into Epochs, and Epochs into Ages.- Each slice corresponds to significant happenings - such as the break-up of continents, dramatic shifts in climate, and even the emergence of particular types of animals and plant life.
- The Holocene itself is subdivided into three stages to denote the epoch's upper, middle and lower phases, according to the International Commission on Stratigraphy (ICS).
NOTE
- The International Commission on Stratigraphy (ICS) is the largest and oldest scientific body in the International Union of Geological Sciences (IUGS).
- It is the official keeper of geologic time, i.e. it precisely defines units (periods, epochs, and age) of the Geologic Time Scale.
- The three substages are:
- The lower or the oldest phase of the Holocene - the exit from the ice age – is known as the Greenlandian.
- The middle phase of the Holocene is known as the Northgrippian and runs from 8,300 years ago up to the start of the
Meghalayan .
The onset for this age was an abrupt cooling, attributed to vast volumes of freshwater from melting glaciers in Canada running into the North Atlantic and disrupting ocean currents. - Meghalayan Age is the youngest (upper) phase.
Methods of Classification
- Each subdivision of the Holocene Epoch is marked out by sediments accumulated on sea floors, lake bottoms, glacial ice and in stalactites and stalagmites across the world.
- Clues to the Greenlandian and Northgrippian stages were available at specific levels in Greenland’s ice cores (snow turns into ice, and preserves a record of the climate each year).
- However, the younger (newer) part of the Holocene, i.e. Meghalayan Age division was marked out by a deviation in the types, or isotopes, of oxygen atoms present in the layers of stalagmite rocks of Mawmluh Cave in Meghalaya.
