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Meghalayan
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. Timeline The Meghalayan begins 4,200 years BP ( 2251 BCE or 7750 HE). Helama & Oinonen (2019) dated the start of the Meghalayan to 2190–1990 BCE. 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. "The fact that the beginning of this age coincides with a cultural shift caused by a global climate event makes it unique," according to Stanley Finney, Secretary General of the International Union of Geological Sciences. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meghalaya
Meghalaya (; "the abode of clouds") is a states and union territories of India, state in northeast India. Its capital is Shillong. Meghalaya was formed on 21 January 1972 by carving out two districts from the Assam: the United Khasi Hills and Jaintia Hills and the Garo Hills.History of Meghalaya State Government of India The estimated population of Meghalaya in 2014 was 3,211,474. Meghalaya covers an area of approximately 22,429 square kilometres, with a length-to-breadth ratio of about 3:1.Meghalaya IBEF, India (2013) The state is bound to the south by the Bangladeshi divisions of Mymensingh Division, Mymensingh and Sylhet Division, Sylhet, to the west by the Bangladeshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northgrippian
In the geologic time scale, the Northgrippian is the middle one of three age (geology), ages or stage (stratigraphy), stages of the Holocene Epoch (geology), Epoch or series (stratigraphy), Series. It was officially ratified by the International Commission on Stratigraphy in June 2018 along with the earlier Greenlandian and later Meghalayan ages/stages. The age takes its name from the North Greenland Ice Core Project (NorthGRIP). The age began 8,276 Before Present, BP (6326 BCE or 3854 Holocene calendar, HE), near the 8.2-kiloyear event, and goes up to the start of the Meghalayan, which began 4,200 BP (2250 BCE or 7750 HE), near the 4.2-kiloyear event. See also * Geologic time scale * North Greenland Ice Core Project * 5th millennium BC References 7th millennium BC Cenozoic, *01 Geological epochs Holocene, * Quaternary geochronology, *03 Quaternary, * {{geochronology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene
The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene is an interglacial period within the ongoing Ice age, glacial cycles of the Quaternary, and is equivalent to Marine isotope stages, Marine Isotope Stage 1. The Holocene correlates with the last maximum axial tilt towards the Sun of the Earth#Axial tilt and seasons, Earth's obliquity. The Holocene corresponds with the rapid proliferation, growth, and impacts of the human species worldwide, including Recorded history, all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban culture, urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global significance for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Epochs
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardised international units of geological time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Before Present
Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1January 1950 as the commencement date (epoch) of the age scale, with 1950 being labelled as the "standard year". The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must account for when using radiocarbon dating for dates of origin that may fall after this year. In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation "RCYBP" stands for the explicit "radio carbon years before present". Usage The BP scale is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indus Valley Civilisation
The Indus Valley Civilisation (IVC), also known as the Indus Civilisation, was a Bronze Age civilisation in the Northwestern South Asia, northwestern regions of South Asia, lasting from 3300 Common Era, BCE to 1300 BCE, and in its mature form from 2600 BCE to 1900 BCE. Together with ancient Egypt and Mesopotamia, it was one of three early civilisations of the Near East and South Asia, and of the three, the most widespread, its sites spanning an area including much of Pakistan, Northwest India, northwestern India and northeast Afghanistan. The civilisation flourished both in the alluvial plain of the Indus River, which flows through the length of Pakistan, and along a system of perennial monsoon-fed rivers that once coursed in the vicinity of the Ghaggar-Hakra River, Ghaggar-Hakra, a seasonal river in northwest India and eastern Pakistan. The term ''Harappan'' is sometimes applied to the Indus Civilisation after its type site Harappa, the first to be exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene Calendar
The Holocene calendar, also known as the Holocene Era or Human Era (HE), is a year numbering system that adds exactly 10,000 years to the currently dominant ( AD/BC or CE/BCE) numbering scheme, placing its first year near the beginning of the Holocene geological epoch and the Neolithic Revolution, when humans shifted from a hunter-gatherer lifestyle to agriculture and fixed settlements. The current year by the Gregorian calendar, AD , is HE in the Holocene calendar. The HE scheme was first proposed by Cesare Emiliani in 1993 (11993 HE), though similar proposals to start a new calendar at the same date had been put forward decades earlier. Emiliani thereby dismissed his original proposal to align the era with the 7980-year Julian cycles, i.e. start with the epoch in 4713 BCE (5288 HE). Overview Cesare Emiliani's proposal for a calendar reform sought to solve a number of alleged problems with the current era, also called the Common Era, which numbers the year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenlandian
In the geologic time scale, the Greenlandian is the earliest age or lowest stage of the Holocene Epoch or Series, part of the Quaternary. Beginning in 11,650 BP (9701 BCE or 300 HE) and ending with the 8.2-kiloyear event (c. 8200–8300 BP, 6200–6300 BCE, 3600–3700 HE), it is the earliest of three sub-divisions of the Holocene. It was officially ratified by the International Commission on Stratigraphy in June 2018 with the later Northgrippian and Meghalayan Ages/Stages. The lower boundary of the Greenlandian Age is the GSSP sample from the North Greenland Ice Core Project in central Greenland (75.1000°N 42.3200°W). The Greenlandian GSSP has been correlated with the end of Younger Dryas The Younger Dryas (YD, Greenland Stadial GS-1) was a period in Earth's geologic history that occurred circa 12,900 to 11,700 years Before Present (BP). It is primarily known for the sudden or "abrupt" cooling in the Northern Hemisphere, when the ... (from near-glacial to in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Time Scale
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardised international units of geological time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to preci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Boundary Stratotype Section And Point
A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted by the International Commission on Stratigraphy, a part of the International Union of Geological Sciences. Most, but not all, GSSPs are based on paleontological changes. Hence GSSPs are usually described in terms of transitions between different faunal stages, though far more faunal stages have been described than GSSPs. The GSSP definition effort commenced in 1977. As of 2024, 79 of the 101 stages that need a GSSP have a ratified GSSP. Rules A geologic section has to fulfill a set of criteria to be adapted as a GSSP by the ICS. The following list summarizes the criteria: * A GSSP has to define the lower boundary of a geologic stage. * The lower boundary has to be defined using a primary mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
