Quaternary

2012-05-15T20:49:26Z

The neogene page says that the quaternary began 2.5 mya, the quaternary page says that the quaternary began 1.8mya -discrepancy.

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	{{Quaternary}}		{{Quaternary}}
-	The '''Quaternary Period''' is the [[Geologic Time Scale\|geologic time]] period after the [[Neogene]] [[Period]], spanning 1.805 +/- 0.005 [[million years ago]] to the present. The Quaternary includes two geologic epochs: the [[Pleistocene]] and the [[Holocene]] [[epoch (geology)\|Epoch]].	+	The '''Quaternary Period''' is the [[Geologic Time Scale\|geologic time]] period after the [[Neogene]] [[Period]], spanning 1.805 +/- 0.005 [[million years ago]] to the present. The Quaternary includes two geologic epochs: the [[Pleistocene]] and the [[Holocene]] [[epoch (geology)\|Epoch]].

-	There is an ongoing debate of the status of Quaternary — a recent proposal from [[International Commission on Stratigraphy]] (ICS) was to make Quaternary a subperiod under [[Neogene]], but that was retracted after criticism from [[International Union for Quaternary Research]] (INQUA), so instead ICS and INQUA agreed to erect Quaternary as an Era, above Neogene, and to place the base for Quaternary at 2.588 ± 3.005, the base for Gelasian Stage. However [[International Union of Geological Sciences\|IUGS]] decided that Quaternary could not start within the Pliocene Epoch thereby splitting it in two, so the decision is still awaiting settlement.<ref>[http://www.stratigraphy.org/report06.pdf ICS: CONSOLIDATED ANNUAL REPORT FOR 2006], last retrieved in 15 June 2007.</ref>	+	There is an ongoing debate of the status of Quaternary — a recent proposal from [[International Commission on Stratigraphy]] (ICS) was to make Quaternary a subperiod under [[Neogene]], but that was retracted after criticism from [[International Union for Quaternary Research]] (INQUA), so instead ICS and INQUA agreed to erect Quaternary as an Era, above Neogene, and to place the base for Quaternary at 2.588 ± 3.005, the base for Gelasian Stage. However [[International Union of Geological Sciences\|IUGS]] decided that Quaternary could not start within the Pliocene Epoch thereby splitting it in two, so the decision is still awaiting settlement.<ref>[http://www.stratigraphy.org/report06.pdf ICS: CONSOLIDATED ANNUAL REPORT FOR 2006], last retrieved in 15 June 2007.</ref>

	==Overview==		==Overview==
-	The term Quaternary ("fourth") was proposed by [[Giovanni Arduino]] in 1759 for alluvial deposits in the [[Po river]] valley in northern [[Italy]]. It was introduced by [[Jules Desnoyers]] in 1829 for sediments of [[France]]'s [[Seine]] Basin that seemed clearly to be younger than [[Tertiary]] [[Period]] [[rock (geology)\|rocks]]. The Quaternary Period follows the Tertiary Period and extends to the present. The Quaternary covers the time span of [[glacier\|glaciations]] classified as the [[Pleistocene]], and includes the present interglacial period, the [[Holocene]]. The alternative usage places the start of the Quaternary at the onset of [[Northern Hemisphere]] glaciation approximately 2.6 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\|Neogene]] [[Period\|Period]]. This latter definition was included in the 2003 edition of the International Stratigraphic Chart, published by the [[International Commission on Stratigraphy]]. See discussion of this topic on the International Subcommission of Quaternary Stratigraphy website [http://www.quaternary.stratigraphy.org.uk].	+	The term Quaternary ("fourth") was proposed by [[Giovanni Arduino]] in 1759 for alluvial deposits in the [[Po river]] valley in northern [[Italy]]. It was introduced by [[Jules Desnoyers]] in 1829 for sediments of [[France]]'s [[Seine]] Basin that seemed clearly to be younger than [[Tertiary]] [[Period]] [[rock (geology)\|rocks]]. The Quaternary Period follows the Tertiary Period and extends to the present. The Quaternary covers the time span of [[glacier\|glaciations]] classified as the [[Pleistocene]], and includes the present interglacial period, the [[Holocene]]. The alternative usage places the start of the Quaternary at the onset of [[Northern Hemisphere]] glaciation approximately 2.6 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]]. This latter definition was included in the 2003 edition of the International Stratigraphic Chart, published by the [[International Commission on Stratigraphy]]. See discussion of this topic on the International Subcommission of Quaternary Stratigraphy website [http://www.quaternary.stratigraphy.org.uk].

	The 1.8–1.6 million years of the Quaternary represents the time during which recognizable 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. 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 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 (and return to salt water) 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 Great Lakes and other major lakes of Canada, and Hudson 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.		The 1.8–1.6 million years of the Quaternary represents the time during which recognizable 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. 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 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 (and return to salt water) 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 Great Lakes and other major lakes of Canada, and Hudson 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.

-	The [[climate]] was one of periodic glaciations with continental glaciers moving as far from the poles as 40 degrees latitude. Few major new animals [[evolution\|evolved]], again presumably because of the short—in geologic terms—duration of the period. There was a major extinction of large mammals in Northern areas at the end of the Pleistocene Epoch. Many forms such as [[saber-toothed cat]]s, [[mammoth]]s, [[mastodon]]s, [[glyptodon]]ts, etc., became [[extinction\|extinct]] worldwide. Others, including [[horse]]s, [[camel]]s and [[cheetah]]s became extinct in [[North America]].	+	The [[climate]] was one of periodic glaciations with continental glaciers moving as far from the poles as 40 degrees latitude. Few major new animals [[evolution\|evolved]], again presumably because of the short—in geologic terms—duration of the period. There was a major extinction of large mammals in Northern areas at the end of the Pleistocene Epoch. Many forms such as [[saber-toothed cat]]s, [[mammoth]]s, [[mastodon]]s, [[glyptodon]]ts, etc., became [[extinction\|extinct]] worldwide. Others, including [[horse]]s, [[camel]]s and [[cheetah]]s became extinct in [[North America]].

	==Quaternary glaciation==		==Quaternary glaciation==
	{{main\|Quaternary glaciation}}		{{main\|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 2.58 Ma and continues to the present-day.	+	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 2.58 Ma and continues to the present-day.

	===Last glaciation===		===Last glaciation===
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	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.		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.

-	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). During the Quaternary period, mammals, flowering plants, and insects dominated the land.	+	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). During the Quaternary period, mammals, flowering plants, and insects dominated the land.

	==References==		==References==

User:Louisvillefossiler

2012-05-15T20:27:18Z

New user account

User talk:101.98.128.11

2012-05-15T20:18:19Z

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	I think I just had a heart attack upon seeing that specimen. WHERE ARE THE PARAMEDICS?!?		I think I just had a heart attack upon seeing that specimen. WHERE ARE THE PARAMEDICS?!?
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		+	Axolotls you say???????
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		+	What size tank do you keep them in, and what's the water temperature? [http://www.multiverses.wikia.com/wiki/X The End Will Begin] <small>([[User:Styracosaurus Rider\|Confront the catalyst]])</small> or <small>{[[User talk:Styracosaurus Rider\|face the inevitable]]}</small> 20:18, May 15, 2012 (UTC)

User talk:Styracosaurus Rider

2012-05-13T05:29:46Z

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	And do you even USE the Fossil Forum anymore?		And do you even USE the Fossil Forum anymore?
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		+	And if it wouldn't be too much trouble, could you please take a photo of all your dinosaur material? Please try to fit it all in a single photograph. :)

Brachyopidae

2012-05-09T00:55:45Z

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	{{Taxobox		{{Taxobox
	\|name = Brachyopidae		\|name = Brachyopidae
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	*''[[Xenobrachyops]]''		*''[[Xenobrachyops]]''
	}}		}}
-	'''Brachyopidae''' is an [[extinct]] [[family]] of [[Temnospondyl]] amphibians.	+	'''Brachyopidae''' is an [[extinct]] [[family]] of [[Temnospondyl]] amphibians.

	==References==		==References==

Fossil Wiki - Recent changes [en]

Quaternary

User:Louisvillefossiler

User talk:101.98.128.11

User talk:Styracosaurus Rider

Brachyopidae