The Quaternary Period is the geologic time period after the Neogene Period roughly 1. The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other The Neogene is a geologic period and system starting 2303 ± 0 8 million years ago to the present. The Quaternary includes two geologic epochs: the Pleistocene —including Gelasian, that used to belong to the Pliocene— and the Holocene Epoch; some geologists recognise the later part of the Holocene as its own epoch, the Anthropocene Epoch. The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent period The Gelasian is a stage whose belonging to either the Pliocene or the Pleistocene Epochs is currently discussed The Pliocene epoch (spelled Pleiocene in some older texts is the period in the Geologic timescale that extends The Holocene is a Geological epoch which began approximately 10000 years ago (about 8000 BC The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other The term Anthropocene is used by some scientists to describe the most recent period in the Earth 's history

There is an ongoing debate of the status of Quaternary — a recent proposal from ICS was to make Quaternary a subperiod under Neogene, but that was retracted at criticism from INQUA, so instead ICS and INQUA agreed to erect Quaternary an Era, above Neogene, and to place the base for Quaternary at 2. The International Commission on Stratigraphy (ICS, sometimes referred to by the unofficial " International Stratigraphic Commission " is a daughter or major Subcommittee The Neogene is a geologic period and system starting 2303 ± 0 The International Union for Quaternary Research (INQUA was founded in 1928 588 ± 0. 005, the base for Gelasian Stage. However IUGS decided that Quaternary could not start within the Pliocene Epoch thereby splitting it in two, so the decision is still awaiting settlement. The International Union of Geological Sciences (IUGS is an international Non-governmental organization devoted to international cooperation in the field of Geology ^[1]

Overview

The term Quaternary ("fourth") was proposed by Giovanni Arduino in 1759 for alluvial deposits in the Po river valley in northern Italy. Giovanni Arduino is the name of Giovanni Arduino (geologist (1714–1795 known as the “father of Italian Geology” Giovanni Arduino (author Year 1759 ( MDCCLIX) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Common year The Po ( Latin: Padus, Po Ligurian: Bo, Greek: Eridanus) is a river that flows 652 km(405 miles (682 km by considering Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest It was introduced by Jules Desnoyers in 1829 for sediments of France's Seine Basin that seemed clearly to be younger than Tertiary Period rocks. Jules Pierre François Stanislaus Desnoyers ( October 8, 1800 &ndash 1887 was a French Geologist and Archaeologist. For the game see 1829 (board game. Year 1829 ( MDCCCXXIX) was a Common year starting on Thursday (link will display This article is about the country For a topic outline on this subject see List of basic France topics. The Seine (sɛn in French) is a slow flowing major River and commercial waterway within the regions of Île-de-France and Haute-Normandie The chuprichondira geological time interval covers roughly the time span between the demise of the non- avian Dinosaurs and beginning of the most recent Ice Age, approximately In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere The Quaternary Period follows the Tertiary Period and extends to the present. The Quaternary covers the time span of glaciations classified as the Pleistocene, and includes the present interglacial period, the Holocene. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent period The Holocene is a Geological epoch which began approximately 10000 years ago (about 8000 BC The alternative usage places the start of the Quaternary at the onset of Northern Hemisphere glaciation approximately 2. Northern Hemisphere is the half of a Planet that is North of the Equator —the word hemisphere literally means 'half ball' 6 million years ago and includes portions of what has been classified as the upper Pliocene. This definition is that favoured by the vast majority of Quaternary scientists. However, some people object to the term Quaternary, instead considering it an informal term for time included in the Neogene Period. The Neogene is a geologic period and system starting 2303 ± 0 This latter definition was included in the 2003 edition of the International Stratigraphic Chart, published by the International Commission on Stratigraphy. The International Commission on Stratigraphy (ICS, sometimes referred to by the unofficial " International Stratigraphic Commission " is a daughter or major Subcommittee See discussion of this topic on the International Subcommission of Quaternary Stratigraphy website [1].

The 1. 8–1. 6 million years of the Quaternary represents the time during which recognisable humans existed. Over this short a time period, the total amount of continental drift was less than 100 km, which is largely irrelevant to palaeontology. Continental drift is the movement of the Earth 's Continents relative to each other Nonetheless, the geological record is preserved in greater detail than that for earlier periods, and is most relatable to the maps of today, revealing in the second half of the twentieth century its own series of extraordinary landform changes. The twentieth century of the Common Era began on The major geographical changes during this time period included emergence of the Strait of Bosphorus and Skagerrak during glacial epochs, which respectively turned the Black Sea and Baltic Sea into fresh water, followed by their flooding by rising sea level; the periodic filling of the English Channel, forming a land bridge between Britain and the European mainland; the periodic closing of the Bering Strait, forming the land bridge between Asia and North America; and the periodic flash flooding of Scablands of the American Northwest by glacial water. The Bosporus or Bosphorus, also known as the Istanbul Strait, (İstanbul Boğazı (Βόσπορος is a Strait that forms the boundary between the The Skagerrak Strait runs between Norway and the southwest coast of Sweden and the Jutland peninsula of Denmark, connecting the The Black Sea is an inland Sea bounded by southeastern Europe, the Caucasus and the Anatolian peninsula ( Turkey The Baltic Sea is a Brackish inland sea located in Northern Europe, from 53°N to 66°N Latitude and from 20°E to 26°E Longitude. The Bering Strait (Берингов пролив Beringov proliv) is a sea Strait between Cape Dezhnev, Russia, the easternmost point (169°43' The Channeled Scablands are unique Geological Erosion features in the U The Great Lakes and other major lakes of Canada, and Hudson's Bay, are also just the results of the last cycle, and are temporary. Following every other ice age within the Quaternary, there was a different pattern of lakes and bays. An ice age is a period of long-term reduction in the Temperature of the Earth 's surface and atmosphere resulting in an expansion of continental Ice sheets

The climate was one of periodic glaciations with continental glaciers moving as far from the poles as 40 degrees latitude. Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of Latitude, usually denoted symbolically by the Greek letter phi ( Φ) gives the location of a place on Earth (or other planetary body north or south of the Few major new animals evolved, again presumably because of the short—in geologic terms—duration of the period. eVolution is the third Album by eLDee, it was due to be released in 2008 There was a major extinction of large mammals in Northern areas at the end of the Pleistocene Epoch.

Many forms such as saber-toothed cats, mammoths, mastodons, glyptodonts, etc. The terms saber-toothed cat, sabertooth, and saber-toothed tiger describe numerous species mainly in the families Felidae (subfamily Machairodontinae A mammoth is any Species of the Extinct Genus Mammuthus. These Proboscideans are members of the elephant family and Mastodons or Mastodonts (from Greek μαστός and οδούς, meaning " Nipple tooth" are members of the extinct Glyptodon (Greek for "grooved or carved tooth" was a large armored Mammal, related to the Armadillo, that lived during the Pleistocene , became extinct worldwide. In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. Others, including horses, camels and cheetahs became extinct in North America. The horse ( Equus caballus) is a hoofed ( Ungulate) Mammal, one of eight living species of the family Equidae. Camels are Even-toed ungulates within the Genus Camelus. The Dromedary, one-humped or Arabian camel has a single hump and the The cheetah ( Acinonyx jubatus) is an atypical member of the cat family ( Felidae) that is unique in its speed while lacking climbing abilities

Quaternary glaciation

Main article: Quaternary glaciation

Glaciation took place repeatedly during the Quaternary the Ice Age - a term coined by Schimper in 1839 that began with the start of the Quaternary about 2. An ice age is a period of long-term reduction in the Temperature of the Earth 's surface and atmosphere resulting in an expansion of continental Ice sheets Year 1839 ( MDCCCXXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian Calendar (or a Common 58 Ma and continues to the present-day.

Last glaciation

Main article: last glacial period

In 1821, a Swiss engineer, Ignaz Venetz, presented an article in which he suggested the presence of traces of the passage of a glacier at a considerable distance from the Alps. "Last glacial" redirects here For the period of maximum glacier extent during this time see Last Glacial Maximum The last glacial period Year 1821 ( MDCCCXXI) was a Common year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Common year Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation Ignaz Venetz (1788–1859 was a Swiss Engineer, naturalist, and Glaciologist. This idea was initially disputed by another Swiss scientist, Louis Agassiz, but when he undertook to disprove it, he ended up affirming his colleague's hypothesis. Jean Louis Rodolphe Agassiz ( May 28 1807 — December 14 1873) was a Swiss - American Zoologist, Glaciologist A year later Agassiz raised the hypothesis of a great glacial period that would have had long-reaching general effects. This idea gained him international fame and led to the establishment of the Glacial Theory.

In time, thanks to the refinement of geology, it has been demonstrated that there were several periods of forward and backward movement of the glaciers and that past temperatures on Earth were very different from today. In particular, the Milankovitch cycles of Milutin Milankovitch are based on the premise that variations in incoming solar radiation are a fundamental factor controlling Earth's climate. Milankovitch cycles are the collective effect of changes in the Earth 's movements upon its climate named after Serbian civil engineer and Mathematician Milutin Milanković ( Serbian Cyrillic: Милутин Миланковић ( May 28, 1879, Dalj, West Syrmia region near

During this time, substantial glaciers advanced and retreated over much of North America and Europe, parts of South America and Asia, and all of Antarctica. The Great Lakes formed and giant mammals flourished in parts of North America and Eurasia not covered in ice. These mammals became extinct when the last Ice Age ended about 11,700 years ago. Modern humans evolved about 190,000 years ago (source: Leakey). Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus

References

1. ^ ICS: CONSOLIDATED ANNUAL REPORT FOR 2006, last retrieved in 15 June 2007.

• The "Quaternary glacial period" section was derived from the article es:Glaciar in the Spanish-language Wikipedia, which was accessed in the version of July 24, 2005