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Evidences of Continental Drift
This theory has been proposed, rejected and accepted over a period of time.
However, there are several evidences that can help prove that this theory is actually
correct.
✦ There is fossilized evidence of primitive flora and fauna found on continents that
have drifted far apart. Fossils of Lystrosaurus have been found in India, South Africa
and Australia while those of Mesosaurus have been found in Western countries of
Africa and Brazil. Fossils of predecessors of Ostriches, which are prominently found
in Africa, have been found in India. Similarly, paleontologists have found fossils of
primitive marsupials in western India. In present day, marsupials are prominently
found only in Australia.
✦ On a closer look, one can find a matching geology on the parallel continents.
One can find a similar geological trend on the western coast of Africa and eastern
coast of South America. Similarly, one can observe a continuity in the mountain
ranges from northern United States till Scandinavia.
✦ A polar ice cap pertaining to the carboniferous period is speculated to have
covered the southern tip of supercontinent Pangaea. Even today, scientists can find
primitive glacial deposits of this same ice cap scattered on different continents.
✦ A careful study reveals a continuity in location of coal mines located in Siberia
and North America.
The Odyssey of Himalayas
The Himalayas are the youngest mountain ranges on Earth. They are the best
evidence to prove that the theory is correct. The tallest peak in the world, Mt.
Everest, is situated in the Himalayas. It is located at a height of 8848 mts.
India is considered to be a part of the Indo-Australian tectonic plate. The theory
states that India and Madagascar were a single landmass about 70 to 80 million
years ago. At some point of time, this tectonic plate broke into two sections. A
smaller section called Madagascar remained near the eastern coast of Africa, while a
bigger section of India moved upwards towards the Eurasian tectonic plate. As per
the continental drift theory, the Indian tectonic plate collided with the Eurasian
tectonic plate approximately 10 million years ago. The impact of this collision,
uplifted the metamorphic and sedimentary rocks of both the tectonic plates, thereby
forming the Himalayan ranges. Geographically, the Himalayas are termed as fold
mountains. A proof of this hypothesis is that the rocks found at the summit of Mt
Everest are categorized as marine limestone. The Indo-Australian tectonic plate is
still in motion, thereby increasing the height of Himalayas by approximately 5 mm
per year. On account of this, the Himalayan region is often quoted to be seismically
active, making it earthquake prone.
PERMIAN STAGE:
This stage took place approximately 225 million years ago.
During this stage, a major portion of Pangaea was a single landmass, while rest of
the Earth's surface was made of oceans. Theory states that the Pacific ocean was on
the western coast of this supercontinent, while the Tethys ocean was on the Eastern
coast.
The drifting process might have started around this time.
TRIASSIC STAGE:
This stage took place around 200 million years ago. According to the theory, two
major landmasses were formed from the drifting process.
A single landmass called Laurasia, consisting of present day North America, Europe
and Asia, was located in the north.
To the south, there was the other landmass, which was called Gondwanaland. This
supercontinent consisted of the present day South America, Africa, India, Antarctica
and Australia.
JURASSIC STAGE:
This is the third stage which is estimated to have happened about 150 million years
ago.
By then, the landmass of Laurasia is expected to have been segregated, with the
continent of North America moving towards the west and the continent of Eurasia
moving towards the east.
Gondwanaland might have split into four sections. These sections include a
conjoined (present day) South America and Africa along with Antarctica, Australia
and present day India.
CRETACEOUS STAGE:
This stage is estimated to have taken place approximately 65 million years ago.
By then, the drifting process had made way for creation of the Atlantic Ocean in
between the western and eastern landmasses.
The continents of South America and Africa are estimated to have drifted apart at
this stage. The Indian tectonic plate or the present day India is expected to have
drifted northwards and collided with the Eurasian tectonic plate during this stage.
PRESENT DAY:
This is the current stage, with seven distinct continents on face of the Earth, namely,
Asia, Africa, Europe, North America, South America, Australia and Antarctica. There
are also five oceans on the face of the Earth, namely the Pacific ocean, the Atlantic
ocean, the Indian ocean, the Arctic ocean and the Antarctic ocean.
Even today, the drifting process is still on, with the continents of Europe and North
America shifting away from one another at the rate of almost 4 cm per year. In the
next millions of years, a new supercontinent is likely to be formed with North
America joining Asia from the eastern side and so on.