Palaeomap and Climate of Different Ages and Reconstruction of the Past Climates, Study Guides, Projects, Research of Geology

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Seminar on

“Palaeomap and climate of different

ages and reconstruction of the past

climates”

CONTENTS

INTRODUCTION

MAPS OF DIFFERENT AGES AND

THEIR CLIMATES

MAJOR ICE AGES

RECONSTRUCTION OF THE

PAST CLIMATES

CONCLUSION

MAPS OF DIFFERENT AGES AND THEIR

CLIMATES

PRECAMBRIAN

Hadean : harsh

terresterial environment,

low oxygen(1%), high

CO2(10%).

Archean : no free oxygen,

reducing condition,

composed of methane,

CO2 and H. like the

present day Venus and

Jupiter

Proterozoic : oxygen rich

i.e from reducing to

oxygenated. Warm

conditions replaced by an

Ice Age, might have

covered the whole earth

PALAEOZOIC ERA

Cambrian Period

Gondwanaland;

Located near the

south pole, covered

by glaciers

North America,

Europe, Siberia and

Asia were all

separate.

Warm and arid in early

part.

Atmospheric oxygen

attains the present

levels, generating an

ozone shield.

Evidence of arid

climate: cambrian of

Silurian Period

North America and

Europe joined by the

end of the Silurian.

The Siberian/Asian

continent was

converging on Europe.

The North

America/Europe

continent began to

approach

Gondwanaland.

Generally warm and

possible dry climate.

Aridity evident by halite

pseudomorphs and salt

Devonian Period

Continued approach of

North America towards

Gondwanaland.

N. America, Europe,

Asia and Siberia were

beginning to form a

second supercontinent:

Laurasia.

Arid climate, aridity

suggested by an

abundance of red beds,

evaporites.

Permian Period

Asia collides with

Europe to form the Ural

Mountains.

One large

supercontinent (called

Pangea) forms with the

merging of Laurasia

and Gondwanaland.

mass extinction

possibly due to ocean

cooling or fluctuating

due to ice sheet.,

reduced aquatic

environments due to

Pangaea forming, ash

from large volcanic

Mesozoic era

Triassic period

All landmass

concentrated into

one-Pangaea,

surrounded by oceans

-Panthalassa

The Triassic climate

was generally hot and

dry, forming typical

red bed sandstones

and evaporites.

Cretaceous Period

Small land masses on

the subducting Pacific

Plate collided with

North America.

Warm climate, mean

global temperature

may have been 6 to 8

degrees higher then

today.

Cenozoic Era

North & South

America, Australia

and Antarctica

spread away from

Pangea, further

opening the Atlantic

Ocean.

Africa collided with

Europe; India collided

with Asia.

The early Cenozoic

was another period

of mountain building

in the Rocky

Mountains.

Over all this time there were other changes taking place:

Variation in O2 levels in the atmosphere

Variation in carbon dioxide

Major ice ages