Paleozoic climate

From Palaeos.org

Jump to: navigation, search
m (added wikilinks)
(redirect)
 
Line 1: Line 1:
-
{{Paleozoic}}
+
#redirect [[Paleozoic]]
-
 
+
-
The [[Early Cambrian]] climate was probably moderate at first, becoming warmer over the course of the [[Cambrian]], as the second-greatest sustained sea level rise in the [[Phanerozoic]] got under way.  However, as if to offset this trend, [[Gondwana]] moved south with considerable speed, so that by the [[Ordovician]] west Gondwana ([[Africa]] and [[South America]]) was centered near  the South Pole.  The Early Paleozoic climate was also strongly zonal, with the result that the "climate", in an abstract sense became warmer, but the living space of most organisms of the time - the continental shelf marine environment - became steadily colder.  However, [[Baltica]] (Northern Europe and Russia) and [[Laurentia]] (eastern North America and Greenland) remained in the tropical zone, while [[China]] and [[Australia]] lay in waters which were at least temperate.  The Early Paleozoic ended, rather abruptly, with the short, but apparently severe, [[Late Ordovician]] Ice Age.  This cold spell caused the second-greatest mass extinction of Phanerozoic time. 
+
-
 
+
-
The Middle Paleozoic was a time of considerable stability.  Sea levels had dropped coincident with the Ice Age, but slowly recovered over the course of the [[Silurian]] and [[Devonian]].  The slow merger of Baltica and Laurentia, and the northward movement of bits and pieces of Gondwana created numerous new regions of relatively warm, shallow sea floor.  As plants took hold on the continental margins, oxygen levels increased and carbon dioxide dropped, although much less dramatically.  The north-south temperature gradient also seems to have moderated, or [[metazoa]]n life simply became hardier, or both.  At any event, the far southern continental margins of [[Antarctica]] and West Gondwana became increasingly less barren.  The Devonian ended with a series of turnover pulses which killed off much of Middle Paleozoic vertebrate life, without noticeably reducing species diversity overall.
+
-
 
+
-
The Late Paleozoic was a time which has left us a good many unanswered questions.  The [[Mississippian]] Epoch began with a spike in atmospheric oxygen, while carbon dioxide plummeted to unheard-of lows.  This destabilized the climate and led to one, and perhaps two, ice ages during the [[Carboniferous]].  These were far more severe than the brief Late Ordovician Ice; but, this time, the effects on world biota were inconsequential.  By the [[Cisuralian]], both oxygen and carbon dioxide had recovered to more normal levels.  On the other hand, the assembly of [[Pangea]] created huge arid inland areas subject to temperature extremes.  The [[Lopingian]] is associated with falling sea levels, increased carbon dioxide and general climatic deterioration, culminating in the devastation of the end-[[Permian]] extinction. 
+
-
 
+
-
 
+
-
<center>[[image:Palaeos logo small.gif|Palaeos com page]]<br>'''[http://www.palaeos.com/Paleozoic/Paleozoic.htm Palaeos com - Paleozoic]'''</center>
+
-
 
+
-
 
+
-
ATW041218.  Text public domain.  No rights reserved.
+

Latest revision as of 06:12, 18 November 2009

Personal tools