GEOGRAPHY
CONTINENTAL DRIFTING
The term continental drifting refers to aparent movement of large land mass relatively to each other from there poler postions to there prese day positions .
There were many theories that were put forword by did geographers and according to them all continnts arw static in nature .
The term continent refers to a large mass of land that is srounded by large water bodies
The term ocean it refers to large mass of land that srounds the land .
A Theory. This is a statement or group of statement with arguement and evidences which tries to explain aparticular act or an event . There werw many theories that were put forword which tries to explaine CONTINETAL DRIFTIMG
THE TYLER’S THEORY.
This rtheory was put forword by American geologist called Tyler in 1910.
According to him ,ther were two large land masses and these were the LAURNSIA and GUDWANALAND .
According to Lauransia was located Northwords near the north pole and the gundwanaland was located near the south pole.
These two land masses started moving mear the equator and during there movement, qreas with high resistance remained and turned in to continents while areas with less resistance were turned in to depressions which were later filled with water hence forming oceans .
Tayler went a head and explained the cause of this movement that during the pre–corombia period ( many million years ago ) the moon came close to the Earth exerting it’s gravitations on it which caused the movement of lauransia and gundwana from there poler position towords the equator .
Tylar went a head and explained that ALPs in Switzerland and the Atlas in North America were formed due collution between Lauransia and Gudwanaland .
However Tyler’s theory was rejected by Geograhers because Tyler dis not explain for the formation of other fold mountains and geologists agreed that diagreed that however close the moon come to earth, it can not cause movement of these huge land masses hence proved technically imposible .
TH ALFRED WEGENER’S THEORY
This theory was put foword by A German climatographer and Geophysist Alfred Wegener and was advanced in 1912 to 1916.
According to him during the pre–corombian period (250million years ), there was one large land mass called PANGEA which was located in the south near the south pole
The Pangea was sorounded by large expenses of water bodies and this was the PATHERANTHER
ILLUSTRATION
Accordind to to wegener during the masozic erababout (180 million years) the pangea cracked and broken in to two large land masses and these land masses ther the lauransia and gundwanaland .
The Lauransia drifted north words and the gundwanaland remained ith the south these two large land masses were seperated by a narrow sea called the sea of Tethy.
ILLUETRATION.
Accordind to awegener , during the creto ceous period (135 millionyears) the Laurasia split to form the northern continets of North America ,Eurasia ,green land .
In the south the gundwanaland also split to form the south continets of Africa, South America ,Austrelia Antactica .
In the North ,North America drited west words away from Eurasia , the Eurasia alao drifted east words to combine with Asia .
In the south South America moved west words away from Africa and then North words to combine with North America . Africa remained in the south Austrelia moved northwords away from Atactic and the east wards to combime with India.
Weginer went a head and expained the cause of the drifting as a centrifugal force / Gravitational forces
WEAKNESS IN WEGENER’S THEORY
Wegener was a climatologist and a geophysist but not a Geologist so he had no business concerning Geomephology and many Geologist under minded his skills because he had not gone any training concerning with methology.
Wegener never bathered to explaine the cause of this centrifugal force / gravitation force.
The Geologists agreed that the centrifugal forces that exerted on earth is much time small to caused drifting of such land masses .
The geologist sugested that if the forces werw real the continets would be moving now qnd there is no external force which can exert on earth and cause continetal drifting .
The fold mountains were formed as a result of compressional forces which led to folding of young fold blocks but not as wegener stated un the theory .
However a credit is give to wegener because is theory resulted in to much research concerning continental drifting .that much of the information concerning continetal drifting resulted from wegener’ theory .
EVIDENCES TO JUSTIFY CONTINETAL DRIFTING .
G M M G S S G P L C
