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The Holocene is the geological epoch that began after the Pleistocene〔(【引用サイトリンク】 title=International Stratigraphic Chart )〕 at approximately 11,700 years before the year 2000AD 〔 Source gives 11,700 "b2 k" (before the year 2000), rather than a figure "before present" (1950).〕 and continues to the present. The term "Recent" (usually capitalised) has often been used as an exact synonym of "Holocene", although this usage is discouraged in 21st-century work.〔 The OED quotes P. Gibbard & T. van Kolfschoten in F. Gradstein et al. Geol. Time Scale 2004 xxii. 451/2: "The term 'Recent' as an alternative to Holocene is invalid and should not be used."〕 The Holocene is part of the Quaternary period. Its name comes from the Greek words (''holos'', whole or entire) and (''kainos'', new), meaning "entirely recent".〔(【引用サイトリンク】url=http://www.etymonline.com/index.php?term=Holocene&allowed_in_frame=0 )〕 It has been identified with the current warm period, known as MIS 1, and can be considered an interglacial in the current ice age based on that evidence. The Holocene also encompasses the growth and impacts of the human species worldwide, including all its written history, development of major civilizations, and overall significant transition toward urban living in the present. Human impacts on modern-era Earth and its ecosystems may be considered of global significance for future evolution of living species, including approximately synchronous lithospheric evidence, or more recently atmospheric evidence of human impacts. Given these, a new term, ''Anthropocene'', is specifically proposed and used informally only for the very latest part of modern history and of significant human impact since the epoch of the ''Neolithic Revolution'' (around 12,000 years BP). ==Overview== It is accepted by the International Commission on Stratigraphy that the Holocene started approximately 11,700 years BP (before present).〔 The epoch follows the Pleistocene and the last glacial period (local names for the last glacial period include the Wisconsinan in North America, the Weichselian in Europe, the Devensian in the United Kingdom, the Llanquihue in Chile and the Otiran in New Zealand). The Holocene can be subdivided into five time intervals, or 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). :''Note: "ka" means "thousand years" (non-calibrated C14 dates)'' The Blytt–Sernander classification of climatic periods defined, initially, by plant remains in peat mosses, is now being explored currently by geologists working in different regions studying sea levels, peat bogs and ice core samples by a variety of methods, with a view toward further verifying and refining the Blytt–Sernander sequence. They find a general correspondence across Eurasia and North America, though the method was once thought to be of no interest. The scheme was defined for Northern Europe, but the climate changes were 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 the Holocene. If subdivision is necessary, periods of human technological development, such as the Mesolithic, Neolithic, and Bronze Age, are usually used. However, the time periods referenced by these terms vary 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 European civilization. According to some scholars, a third division, the Anthropocene, began in the 18th century.〔Fred Pearce (2007). ''With Speed and Violence'', p. 21. ISBN 978-0-8070-8576-9〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Holocene」の詳細全文を読む スポンサード リンク
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