Changes

According to secular [[geology]], there have been several Ice Ages, the oldest being 2.3 [[billion]] years ago, and the most recent finishing around 11,500 years ago.<ref name="WBE" /><ref name="CAB">Batten, 2007</ref>

According to secular [[geology]], there have been several Ice Ages, the oldest being 2.3 [[billion]] years ago, and the most recent finishing around 11,500 years ago.<ref name="WBE" /><ref name="CAB">Batten, 2007</ref>

a theory first proposed by [[Louis Agassiz]] to explain anomalies such as the existence of the [[Great Lakes]].<ref>[http://earthguide.ucsd.edu/virtualmuseum/climatechange2/02_1.shtml Discovery of the Great Ice Age]</ref><ref>Aber, James S., [http://academic.emporia.edu/aberjame/histgeol/agassiz/agassiz.htm Jean Louis Rodolphe Agassiz]</ref>  The theory suggests that there were one or more

The theory was first proposed by [[Louis Agassiz]] to explain anomalies such as the existence of the [[Great Lakes]].<ref>[http://earthguide.ucsd.edu/virtualmuseum/climatechange2/02_1.shtml Discovery of the Great Ice Age]</ref><ref>Aber, James S., [http://academic.emporia.edu/aberjame/histgeol/agassiz/agassiz.htm Jean Louis Rodolphe Agassiz]</ref>   

Earth and rock worn and smoothed by ice sheets, along with U-shaped [[valley]]s and termination deposition debris, are the main evidences for an Ice Age, and there is evidence of such [[glacier|glaciation]] covering northern [[Europe]] (including most of [[Britain]]), most of [[Canada]], and into the northern parts of eastern half of the [[United States]].<ref Name="WBE">Ice Age, World Book Encyclopedia 2000 CD ROM</ref>

Earth and rock worn and smoothed by ice sheets, along with U-shaped [[valley]]s and termination deposition debris, are the main evidences for an Ice Age, and there is evidence of such [[glacier|glaciation]] covering northern [[Europe]] (including most of [[Britain]]), most of [[Canada]], and into the northern parts of eastern half of the [[United States]].<ref Name="WBE">Ice Age, World Book Encyclopedia 2000 CD ROM</ref>