__Period ____Age __Mountains __Climate

CENOZOIC
>
Quaternary ........ 3 ............................... Ice age
>Tertiary ............ 70 ...... Alpine
....................................................................
Warm
MESOZOIC
.............................................................
Glaciations
>
Cretaceous ...... 135 ...... Laramide
>
Jurassic ........... 180 ................................ Warm
>Triassic ............ 255 ................................ Warm

PALEOZOIC
..............................................................
Glaciations
>Permian ............ 270 ....... Hercynian
>Carboniferous .. 350 ............................... Warm
>
Devonian .......... 400 ....... Caledonian ....... ?
>
Silurian ............. 440 ................................Warm
>Ordovician ........ 500 ...............................Warm
>Cambrian .......... 600 ......................... Glaciation
.............................................
Charnian
..................................................................... Warm

PRECAMBRIAN

>Crust formed ....
.4500

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Acknowledgment

Jerry Collette, and Nancy Wilson
are thanked for their help in setting up this site
.