Scientists have approved three new ages on a geologic time scale of Holocene Epoch viz. Meghalaya Age, Middle Holocene Northgrippian Age, and Early Holocene Greenlandian Age. These three new ages of Holocene Epoch are represented by the wealth of sediments that accumulated worldwide on the sea floor, on lake bottoms, as glacial ice, and as calcite layers in stalactites and stalagmites. Together the strata of three new stages comprise the Holocene series.
It is named after the cave in the Indian state of Meghalaya. It has helped to define climatic events 4,200 years ago, marking the beginning of a phase that continues till 20 July 2018. The lower boundary of this stage is defined at a specific level in a stalagmite from a cave in the northeastern Indian state.
The droughts over the 200-year period had resulted in human migrations in Egypt, Syria, Palestine, Mesopotamia, Greece, Indus valley and Yangtze river valley. The change in the global climate during the Meghalayan Age was likely triggered by shifts in ocean and atmospheric circulation.
Geologists divide 4.6-billion-year existence of Earth into distinct periods. Each period corresponds to significant events such as the break-up of continents, shifts in climate, and the emergence of particular types of animals and plant life. These units of geologic time scale are based on sedimentary strata that have accumulated over time and contain within them sediment types, fossils and chemical isotopes that record passage of time as well as physical and biological events that produced them. Those intervals of sedimentary strata on which ages are based are referred to as stages.