Wanajiolojia wameashiria awamu mpya katika historia ya dunia baada ya kugundua ushahidi huko Meghalaya, India
The current age which we are living in has been recently officially designated at the ‘Meghalayan Age’ by the International Geologic Time scale. This scale divides the history of our sayari into different eons, eras, periods, epochs and ages. The timing of events on the basis of which these time periods are divided is collated by geologists and archaeologists worldwide and is based upon substantial events like continents breaking up, dramatic change in climatic conditions, extinction or emergence of certain animals and plants. The units of this scale are based upon proof and evidence of sedimentary layers which have collected over time and these layers contain different sediments, fossils and chemical isotopes. Such strata bear recordings through a passage of time which also convey associated physical and biological events. This is called geologic age dating where each of such material are assigned an age and then the likely events around it are predicted. This is how we know today that earth is 4.6 billion years old. The International Commission on Stratigraphy (IUGS) is chiefly responsible for regulating the Geologic Time Scale.
Enzi ya sasa tunayoishi, - enzi ya Holocene - imesasishwa na kugawanywa katika tatu mpya. zama za kijiolojia ambazo ni Holocene ya Mapema inayoitwa Greenlandian, Halocene ya Kati iitwayo Northgrippian na Marehemu Halocene inayoitwa enzi ya Meghlayan. Umri wa Greenlandia umewekwa alama wakati enzi ya barafu ilimalizika na ongezeko la joto lilianza duniani karibu miaka 12000 iliyopita. Umri wa Northgrippian ulianza karibu miaka 8000 iliyopita. Enzi hizi zote mbili zimewekwa alama na chembe za barafu zinazopatikana Greenland. Umri mpya tofauti wa Meghalayan ambao sasa umetambuliwa ulianza miaka 4,200 iliyopita na hadi leo. Shirika la Umoja wa Kimataifa wa Sayansi ya Jiolojia linawajibika kwa viwango hivi vya kimataifa katika jiolojia. Tafiti zimechukua hadi miaka minane kuashiria tarehe za umri wa Meghalayan.
All ages have been assigned unique names based upon their origin or start. The Greenlandian and Northgrippian ages are named for the NorthGRIP site in Greenland. This site depicts the swift warming of the sayari signifying the culmination of ice age followed by a swift universal cooling at the start of Northgrippian age which was caused by entry of melted ice water into the North Atlantic. Further, around 4,200 years ago, a significantly drier phase or aridification has been identified by researchers which they have designated as the start of Meghlayan Age. The Meghalayan age is termed after a stalagmite (a type of rock formation) in Mawmlul cave located in the north eastern state Meghalaya in India to mark the exact origin of this age. The word “Meghalaya' ina maana "makao ya mawingu" katika Sanskrit. Muhuri wa nyakati wa enzi hii unaeleweka kwa kueleza kwamba stalagmite hii iliwekwa kwenye sakafu ya pango kutoka kwenye amana za madini kwa maelfu kadhaa ya miaka kwa sababu ya maji ya mvua yanayoingia ndani ya pango kupitia matone ya dari. Hii ilitokea labda kwa sababu ya mabadiliko ya bahari na mzunguko wa anga. Tabaka za madini zinaonyesha mabadiliko ya mvua kwa wakati kwani saini zao za kemikali zinaonyesha kuwa mabadiliko ya stalagmite katika isotopu ya atomi ya oksijeni yalisababisha eneo hilo kukumbwa na upungufu wa asilimia 20-30 wa mvua za masika. Hii inachukuliwa kuwa ushahidi muhimu kwa ugunduzi huu. Kwa hakika, ushahidi huo umegunduliwa katika mabara yote saba ya Dunia. Hii 'rasimu kubwa' ilizindua enzi mpya ya kijiolojia. Hali hiyo ya hali ya hewa iliyokithiri pia ingeacha kuporomoka kwa ustaarabu na kung'oa makazi ya watu hasa wale wanaojishughulisha na kilimo karibu na Bahari ya Mediterania, Mashariki ya Kati na Asia kama inavyoonyeshwa katika tafiti. Madhara ya hii 'rasimu kubwa' inaonekana kuwa ilidumu kwa zaidi ya miaka 200. Wataalamu wengi wanaamini tukio hili kuwa na uhusiano mkubwa na sababu za kijamii na kiuchumi.
The smallest global climatic event in the history of our sayari has been discovered for the first time and it furthers our understanding of Earth’s complete geological history. This is a remarkable discovery and an addition into the history of Holocene and also archaeology. Geologists are planning to add a new epoch after the Holocene which is being called the Anthropocene which would mark the impact of humans on the geology of the sayari after industrialization.
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{Unaweza kusoma karatasi asili ya utafiti kwa kubofya kiungo cha DOI kilichotolewa hapa chini katika orodha ya (vyanzo) vilivyotajwa}
Chanzo (s)
Tume ya Kimataifa ya Stratigraphy. www.stratigraphy.org. [Ilitumika Agosti 5 2018].
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