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Holocene
Preboreal (10 ka - 9 ka), Boreal (9 ka - 8 ka), Atlantic (8 ka - 5 ka), Subboreal (5 ka - 2.5 ka) and Subatlantic (2. The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent period The Blytt-Sernander classification or sequence is a series of north European climatic periods or phases based on the study of Danish Peat bogs by Axel In the 8th millennium BC, Agriculture becomes widely practiced in the Fertile Crescent and Anatolia. In Paleoclimatology of the Holocene, the Boreal was the first of the Blytt-Sernander sequence of North European climatic phases that were originally During the 7th millennium BC, Agriculture spreads from Anatolia to the Balkans. The Atlantic in palaeoclimatology was the warmest and most moist Blytt-Sernander period Pollen zone and chronozone of Holocene north Europe. During the 6th millennium BC, Agriculture spreads from the Balkans to Italy and Eastern Europe and from Mesopotamia to Egypt. The 4th millennium BC saw major changes in human culture It marks the beginning of the Bronze Age and of Writing. The Blytt-Sernander classification or sequence is a series of north European climatic periods or phases based on the study of Danish Peat bogs by Axel The 3rd millennium BC spans the Early to Middle Bronze Age. It represents a period of time in which Imperialism, or the desire to conquer grew to prominence The 1st millennium BC encompasses the Iron Age and sees the rise of successive empires The Blytt-Sernander classification or sequence is a series of north European climatic periods or phases based on the study of Danish Peat bogs by Axel 5 ka - present). Anthropocene

The Holocene is a geological epoch, which began approximately 11,550 calendar years BP (about 9600 BC). The term Anthropocene is used by some scientists to describe the most recent period in the Earth 's history Geology (from Greek γη gê, "earth" and λόγος Logos, "speech" lit The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other Before Present (BP years are a time scale used in Archaeology, Geology, and other scientific disciplines to specify when events in the past occurred According to traditional geological thinking, the Holocene continues to the present. However, recently there have been papers that propose that the Holocene ended about 300 BP (1700 AD) with the start of the Anthropocene ^[1]. The term Anthropocene is used by some scientists to describe the most recent period in the Earth 's history The Holocene is part of the Neogene and Quaternary periods. The Neogene is a geologic period and system starting 2303 ± 0 Overview The term Quaternary ("fourth" was proposed by Giovanni Arduino in 1759 for alluvial deposits in the Po river valley in northern Its name comes from the Greek words ὅλος (holos, whole or entire) and καινός (kainos, new), meaning "entirely recent". It has been identified with MIS 1 and can be considered an interglacial in the current ice age. Marine isotopic stage s (MIS are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data reflecting temperature curves derived An interglacial is a geological interval of warmer global average temperature that separates Glacial periods within an Ice age. 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

Contents 1 Overview 2 Geology 3 Climate 4 Ecological developments 5 Human developments 6 Impact events 7 Further reading 8 See also 9 References 10 External links

Overview

It is generally accepted that the Holocene started 10 ka (thousand years) before present (11,703 calendar years before 1950). Annum is one form of the Latin noun meaning Year, not a form normally used for derivatives in modern languages the accusative singular Before Present (BP years are a time scale used in Archaeology, Geology, and other scientific disciplines to specify when events in the past occurred The period precedes the Weichsel glacial. The Holocene can be subdivided into five chronozones based on climatic fluctuations:

• Preboreal (10 ka - 9 ka),
• Boreal (9 ka - 8 ka),
• Atlantic (8 ka - 5 ka),
• Subboreal (5 ka - 2. 5 ka) and
• Subatlantic (2. 5 ka - present).

Human civilization dates entirely within the Holocene. The Blytt-Sernander classification of climatic periods defined, initially, by plant remains in peat mosses, is now of purely historical interest. The Blytt-Sernander classification or sequence is a series of north European climatic periods or phases based on the study of Danish Peat bogs by Axel The scheme was defined for north Europe, but the climate changes have been claimed to occur more widely. The periods of the scheme include a few of the final, pre-Holocene, oscillations of the last glacial period and then classify climates of more recent prehistory.

Paleontologists have defined no faunal stages for Holocene. If subdivision is necessary, periods of human technological development such as the Mesolithic, Neolithic, and Bronze Age are usually used. The Mesolithic or Middle Stone Age was a period in the development of human technology in between the Paleolithic or Old Stone Age and the Neolithic or New Stone Age The Neolithic (from Greek νεολιθικός — neolithikos from νέος neos, "new" + λίθος lithos The term Bronze Age refers to a period in human cultural development when the most advanced Metalworking (at least in systematic and widespread use included techniques for However, the time periods referenced by these terms varies with the emergence of those technologies in different parts of the world.

Climatically, the Holocene may be divided evenly into the Hypsithermal and Neoglacial periods; the boundary coincides with the start of the Bronze Age in western civilisation. The Holocene Climate Optimum was a warm period during roughly the interval 9000 to 5000 years B The neoglaciation was a period of the Holocene starting around 5500 BP (3500 BC and ending in the 20th century According to some scholars, a third division, the Anthropocene, began in the 18th Century ^[2]. It is debatable whether this is an age within, or follows, the Holocene epoch.

Geology

Continental motions are less than a kilometre over a span of only 10 ka. However, ice melt caused world sea levels to rise about 35 m (110 ft) in the early part of the Holocene. Sea-level rise is an increase in Sea level. Multiple complex factors may influence this change In addition, many areas above about 40 degrees north latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 m (600 ft) over the late Pleistocene and Holocene, and are still rising today.

The sea level rise and temporary land depression allowed temporary marine incursions into areas that are now far from the sea. Holocene marine fossils are known from Vermont, Quebec, Ontario, and Michigan. Vermont ( is a state in the New England region of the northeastern United States of America. Quebec (kwɨˈbɛk Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec Michigan ( is a Midwestern state of the United States of America. Other than higher latitude temporary marine incursions associated with glacial depression, Holocene fossils are found primarily in lakebed, floodplain, and cave deposits. Holocene marine deposits along low-latitude coastlines are rare because the rise in sea levels during the period exceeds any likely upthrusting of non-glacial origin.

Post-glacial rebound in the Scandinavia region resulted in the formation of the Baltic Sea. Post-glacial rebound (sometimes called continental rebound, isostatic rebound, isostatic adjustment or post-ice-age isostatic recovery) Terminology and usage As a cultural term "Scandinavia" has no official definition and is subject to usage by those who identify with the culture in question as well 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 region continues to rise, still causing weak earthquakes across Northern Europe. An earthquake is the result of a sudden release of energy in the Earth 's crust that creates Seismic waves Earthquakes are recorded with a Seismometer Northern Europe is a term for the northern part of Europe. The United Nations defines Northern Europe as (Finland The equivalent event in North America was the rebound of Hudson Bay, as it shrank from its larger, immediate post-glacial Tyrrell Sea phase, to near its present boundaries. The Tyrrell Sea, named for Canadian Geologist Joseph Tyrrell, is another name for prehistoric Hudson Bay, namely as it existed during the retreat

Climate

Although geographic shifts in the Holocene were minor, climatic shifts were very large. Ice core records show that before the Holocene there were global warming and cooling periods, but climate changes became more regional at the start of the Younger Dryas. An ice core is a Core sample from the accumulation of snow and ice over many years that have re-crystallized and have trapped air bubbles from previous time periods However, the Huelmo/Mascardi Cold Reversal in the Southern Hemisphere began before the Younger Dryas, and the maximum warmth flowed south to north from 11,000 to 7,000 years ago. The Huelmo/Mascardi Cold Reversal (HMCR is the name given to a cooling event in South America between 11400 and 10200 14C years BP. It appears that this was influenced by the residual glacial ice remaining in the Northern Hemisphere until the latter date.

The hypsithermal was a period of warming in which the global climate became 0. The Holocene Climate Optimum was a warm period during roughly the interval 9000 to 5000 years B 5–2°C warmer than today. However, the warming was probably not uniform across the world. This period ended about 5,500 years ago, when the earliest human civilizations in Asia and Africa were flourishing. This period of warmth ended with the descent into the Neoglacial. At that time, the climate was not unlike today's, but there was a slightly warmer period from the 10th–14th centuries known as the Medieval Warm Period. The Medieval Warm Period (MWP or Medieval Climate Optimum was a time of unusually Warm Climate in the North Atlantic region lasting from about This was followed by the Little Ice Age, from the 13th or 14th century to the mid 19th century, which was a period of significant cooling, though not everywhere as severe as previous times during neoglaciation. The Little Ice Age (LIA was a period of cooling occurring after a warmer era known as the Medieval Warm Period or Medieval Climate Optimum

The Holocene warming is an interglacial period and there is no reason to believe that it represents a permanent end to the current ice age. However, the current global warming may result in the Earth becoming warmer than the Eemian Interglacial, which peaked at roughly 125,000 years ago and was warmer than the Holocene. Global warming is the increase in the average measured temperature of the The Eemian interglacial era, now known as the Eemian Stage is temporally equivalent to the Sangamon Stage in North America, the Ipswichian Stage in This prediction is sometimes referred to as a super-interglacial.

Compared to glacial conditions, habitable zones have expanded northwards, reaching their northernmost point during the hypsithermal. Greater moisture in the polar regions has caused the disappearance of steppe-tundra. Steppe-tundra is a sparse dry-climate vegetation type which was widespread during Pleistocene times at mid-latitudes of North America and Eurasia, but no

Ecological developments

Animal and plant life have not evolved much during the relatively short Holocene, but there have been major shifts in the distributions of plants and animals. A number of large animals including mammoths and mastodons, saber-toothed cats like Smilodon and Homotherium, and giant sloths disappeared in the late Pleistocene and early Holocene—especially in North America, where animals that survived elsewhere (including horses and camels) became extinct. 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 The terms saber-toothed cat, sabertooth, and saber-toothed tiger describe numerous species mainly in the families Felidae (subfamily Machairodontinae Smilodon (ˈsmаɪləˌdɒn sometimes called saber-toothed tiger, is an extinct Genus of large machairodontine Saber-toothed Homotherium is a Genus of machairodontine Saber-toothed cats often termed 'scimitar cats' that lived approximately 5 million to 10000 Ground sloths are a diverse group of Extinct Sloths Mammals in the edentate Superorder Xenarthra. This extinction of American megafauna has been explained as caused by the arrival of the ancestors of Amerindians; though most scholars assert that climatic change also contributed. Megafauna are species of large Animals ( Greek μεγας large + modern Latin fauna animal For indigenous peoples in the United States other than Hawaii and Alaska see also Native Americans in the United States.

Throughout the world, ecosystems in cooler climates that were previously regional have been isolated in higher altitude ecological "islands. "

The 8.2 ka event, an abrupt cold spell recorded as a negative excursion in the δ¹⁸O record lasting 400 years, is the most prominent climatic event occurring in the Holocene epoch, and may have marked a resurgence of ice cover. The Holocene is a Geological epoch which began approximately 10000 years ago (about 8000 BC It is thought that this event was caused by the final drainage of Lake Agassiz which had been confined by the glaciers, disrupting the thermohaline circulation of the Atlantic [1]. Lake Agassiz was an immense Glacial lake located in the center of North America. The term thermohaline circulation (THC refers to the part of the large-scale ocean circulation that is thought to be driven by global density gradients created by surface heat and

Human developments

The beginning of the Holocene corresponds with the beginning of the Mesolithic age in most of Europe; but in regions such as the Middle East and Anatolia with a very early neolithisation, Epipaleolithic is preferred in place of Mesolithic. The Mesolithic or Middle Stone Age was a period in the development of human technology in between the Paleolithic or Old Stone Age and the Neolithic or New Stone Age The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. Anatolia (Anadolu Ανατολία Anatolía) or Asia minor, comprising most of modern Turkey, is the geographic region bounded by the Black The Neolithic Revolution was the first Agricultural revolution &mdashthe transition from hunting and gathering communities and bands to Agriculture and The Epipaleolithic is a term used for the "final Upper Palaeolithic industries occurring at the end of the final glaciation which appear to merge technologically into the Cultures in this period include: Hamburgian, Federmesser, and the Natufian culture. The Hamburg culture ( 12400 BC - 12100 BC, C14-years was a late Upper Paleolithic culture of Reindeer hunters during the last part of the Federmesser culture is a toolmaking tradition of the late Upper Palaeolithic era of the Northern European Plain dating to between c The Natufian culture (natʏˈfjẽː existed in the Mediterranean region of the Levant.

Both are followed by the aceramic Neolithic (Pre-Pottery Neolithic A and Pre-Pottery Neolithic B) and the pottery Neolithic. The Pre-Pottery Neolithic A (short PPNA around 9000 BC represents the early Neolithic in the Levantine and upper Mesopotamian region of the Fertile Pre-Pottery Neolithic B (PPNB is a division of the Neolithic developed by Dame Kathleen Kenyon during her Archaeological excavations at Jericho The Neolithic (from Greek νεολιθικός — neolithikos from νέος neos, "new" + λίθος lithos

Impact events

Within the Holocene numerous meteorite events have been recently discovered in Europe, as well as in seas such as the Indian Ocean and near remote Siberia. A meteorite is a natural object originating in Outer space that survives an impact with the Earth 's surface The Indian Ocean is the third largest of the world's Oceanic divisions covering about 20% of the water on the Earth 's surface Siberia (Сиби́рь Sibir) is the name given to the vast region constituting almost all of Northern Asia and for the most part currently serving It has been speculated that an impact effect such as that represented today by the Burckle crater^[3] or the Chiemgau Impact crater^[4] could have dramatically affected human culture in its early history by the creation of megatsunamis, perhaps inspiring deluge or inundation stories such as that of Noah's Flood. Burckle Crater is an undersea crater likely to have been formed by a very large scale Comet or Meteorite impact event. Chiemgau impact crater refers to Lake Tüttensee created by a Holocene meteorite impact near Lake Chiemsee and the foothills of the Alps in southeast Germany Mega-tsunami (also known as iminami or "wave of purification" is an informal term to indicate a Tsunami that has initial Wave heights that are In the relatively recent geological past several great floods are widely suspected to have occurred with varying amounts of supporting evidence usually as a result of the last Ice The story of a Great Flood (also known as the Deluge) sent by a Deity or deities to destroy Civilization as an act of Divine retribution is a A washout effect from such waves may have breached land bridges with sudden massive erosion, along with violent weather changes. Competing reasons for the various basin floods also include climate change and earthquake fault lines weakening the barriers to ocean encroachment.

Further reading

• Neil Roberts The Holocene: an environmental history (Blackwell Publishing)
• Mackay, A. W. , Battarbee, R. W. , Birks, H. J. B. & Oldfield, F. (2003) Editors. Global change in the Holocene. Publisher: Arnold, London. 528 pp (29 chapters)

See also

• 8.2 kiloyear event
• Anthropocene
• Blytt-Sernander
• Deluge (prehistoric)
• Geologic timescale
• Holocene calendar
• Holocene extinction event
• Holocene Impact Working Group
• Impact events
• Neolithic Subpluvial
• Older Peron
• Piora Oscillation
• 10th millennium BC
• Last Glacial Maximum
• 1 E11 s

References

• Ogg, Jim; June, 2004, Overview of Global Boundary Stratotype Sections and Points (GSSP's) http://www.stratigraphy.org/gssp.htm Accessed April 30, 2006

External links

• http://extinctanimals.petermaas.nl/
• The 8.2 ka event
• Detecting Holocene changes in thermohaline circulation

Neogene period
Quaternary
Pliocene	Pleistocene	Holocene
← Neogene | Gelasian	Early | Middle | Late

The Neogene is a geologic period and system starting 2303 ± 0 Overview The term Quaternary ("fourth" was proposed by Giovanni Arduino in 1759 for alluvial deposits in the Po river valley in northern The Pliocene epoch (spelled Pleiocene in some older texts is the period in the Geologic timescale that extends The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent period The Neogene is a geologic period and system starting 2303 ± 0 The Gelasian is a stage whose belonging to either the Pliocene or the Pleistocene Epochs is currently discussed Early Pleistocene (also known as Lower Pleistocene, or Calabrian) is a subdivision of the Pleistocene Epoch of the Geologic time scale So far the Pleistocene Series is not subdivided into formal units (i The Late Pleistocene (also known as Upper Pleistocene or the Tarantian) is a stage of the Pleistocene Epoch.

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