Continental Drift Theory | Geography for UPSC 2024 (Pre & Mains) PDF Download

 Page 1


 
CONTINENTAL DRIFT THEORY: 
INTRODUCTION: 
Continental drift describes one of the earliest ways geologists 
thought continents moved over time. Today, the theory of continental drift has 
been replaced by the science of plate tectonics.  
 
The speculation that continents might have 'drifted' was first put forward by 
Abraham Ortelius in 1596. The concept was independently and more fully 
developed by Alfred Wegener in 1912, but his theory was rejected by many for 
lack of any motive mechanism. 
  
The theory of continental drift is most associated with the scientist Alfred 
Wegener. In the early 20th century, Wegener published a paper explaining his 
theory that the continental landmasses were “drifting” across the Earth, 
sometimes plowing through oceans and into each other. He called this 
movement continental drift.  
  
Continental Drift Theory (Alfred Wegener, 1922) 
According to Wegener, all the continents formed a single continental mass, a 
mega ocean surrounded.  The super continent was named PANGAEA, which 
meant all earth. The mega-ocean was called PANTHALASSA, meaning all 
water. He argued that, around 200 million years ago, the super continent, 
Pangaea, began to split. Pangaea first broke into two large continental masses 
as Laurasia and Gondwanaland forming the northern and southern components 
respectively with Tethys sea . Subsequently, Laurasia and Gondwanaland 
continued to break into various smaller continents that exist today. 
Evidence in support of Continental Drift 
Physical Features 
The shorelines of Africa and South America facing each other have a 
remarkable and unmistakable match, especially, the bulge of Brazil fits into 
the Gulf of Guinea.Greenland seems to fit in well with Ellesmere and Baffin 
islands. The west coast of India, Madagascar and Africa seem to have been 
Page 2


 
CONTINENTAL DRIFT THEORY: 
INTRODUCTION: 
Continental drift describes one of the earliest ways geologists 
thought continents moved over time. Today, the theory of continental drift has 
been replaced by the science of plate tectonics.  
 
The speculation that continents might have 'drifted' was first put forward by 
Abraham Ortelius in 1596. The concept was independently and more fully 
developed by Alfred Wegener in 1912, but his theory was rejected by many for 
lack of any motive mechanism. 
  
The theory of continental drift is most associated with the scientist Alfred 
Wegener. In the early 20th century, Wegener published a paper explaining his 
theory that the continental landmasses were “drifting” across the Earth, 
sometimes plowing through oceans and into each other. He called this 
movement continental drift.  
  
Continental Drift Theory (Alfred Wegener, 1922) 
According to Wegener, all the continents formed a single continental mass, a 
mega ocean surrounded.  The super continent was named PANGAEA, which 
meant all earth. The mega-ocean was called PANTHALASSA, meaning all 
water. He argued that, around 200 million years ago, the super continent, 
Pangaea, began to split. Pangaea first broke into two large continental masses 
as Laurasia and Gondwanaland forming the northern and southern components 
respectively with Tethys sea . Subsequently, Laurasia and Gondwanaland 
continued to break into various smaller continents that exist today. 
Evidence in support of Continental Drift 
Physical Features 
The shorelines of Africa and South America facing each other have a 
remarkable and unmistakable match, especially, the bulge of Brazil fits into 
the Gulf of Guinea.Greenland seems to fit in well with Ellesmere and Baffin 
islands. The west coast of India, Madagascar and Africa seem to have been 
 
joined. North and South America on one side and Africa and Europe on the 
other fit along the mid-Atlantic ridge. The Caledonian and Hercynian 
mountains of Europe and the Appalachians of USA seem to be one continuous 
series. 
Rocks of Same Age Across the Oceans 
The radiometric dating methods developed in the recent period have facilitated 
correlating the rock formation from different continents across the vast ocean. 
The belt of ancient rocks of 2,000 million years from Brazil coast matches 
with those from western Africa.  The earliest marine deposits along the 
coastline of South America and Africa are of the Jurassic age. This suggests 
that the ocean did not exist prior to that time. 
Distribution of Fossils 
When identical species of plants and animals adapted to living on land or in 
fresh water are found on either side of the marine barriers, a problem arises 
regarding accounting for such distribution.  The observations that Lemurs 
occur in India, Madagascar and Africa led some to consider a contiguous 
landmass “Lemuria” linking these three landmasses.  Mesosaurus was a small 
reptile adapted to shallow brackish water.  The skeletons of these are found 
only in two localities : the Southern Cape province of South Africa and Iraver 
formations of Brazil. The two localities presently are 4,800 km apart with an 
ocean in between them. 
Botanical Evidence 
Presence of glossopteris vegetation in carboniferous rocks of India, Australia, 
South Africa, Falkland Islands (Overseas territory of UK), Antarctica, etc. can 
be explained on the basis of the fact that parts were linked in the past. 
Tillite deposits 
It is the sedimentary rock formed out of deposits of glaciers. The Gondwana 
system of sediments from India is known to have its counter parts in six 
different landmasses of the Southern Hemisphere. 
Page 3


 
CONTINENTAL DRIFT THEORY: 
INTRODUCTION: 
Continental drift describes one of the earliest ways geologists 
thought continents moved over time. Today, the theory of continental drift has 
been replaced by the science of plate tectonics.  
 
The speculation that continents might have 'drifted' was first put forward by 
Abraham Ortelius in 1596. The concept was independently and more fully 
developed by Alfred Wegener in 1912, but his theory was rejected by many for 
lack of any motive mechanism. 
  
The theory of continental drift is most associated with the scientist Alfred 
Wegener. In the early 20th century, Wegener published a paper explaining his 
theory that the continental landmasses were “drifting” across the Earth, 
sometimes plowing through oceans and into each other. He called this 
movement continental drift.  
  
Continental Drift Theory (Alfred Wegener, 1922) 
According to Wegener, all the continents formed a single continental mass, a 
mega ocean surrounded.  The super continent was named PANGAEA, which 
meant all earth. The mega-ocean was called PANTHALASSA, meaning all 
water. He argued that, around 200 million years ago, the super continent, 
Pangaea, began to split. Pangaea first broke into two large continental masses 
as Laurasia and Gondwanaland forming the northern and southern components 
respectively with Tethys sea . Subsequently, Laurasia and Gondwanaland 
continued to break into various smaller continents that exist today. 
Evidence in support of Continental Drift 
Physical Features 
The shorelines of Africa and South America facing each other have a 
remarkable and unmistakable match, especially, the bulge of Brazil fits into 
the Gulf of Guinea.Greenland seems to fit in well with Ellesmere and Baffin 
islands. The west coast of India, Madagascar and Africa seem to have been 
 
joined. North and South America on one side and Africa and Europe on the 
other fit along the mid-Atlantic ridge. The Caledonian and Hercynian 
mountains of Europe and the Appalachians of USA seem to be one continuous 
series. 
Rocks of Same Age Across the Oceans 
The radiometric dating methods developed in the recent period have facilitated 
correlating the rock formation from different continents across the vast ocean. 
The belt of ancient rocks of 2,000 million years from Brazil coast matches 
with those from western Africa.  The earliest marine deposits along the 
coastline of South America and Africa are of the Jurassic age. This suggests 
that the ocean did not exist prior to that time. 
Distribution of Fossils 
When identical species of plants and animals adapted to living on land or in 
fresh water are found on either side of the marine barriers, a problem arises 
regarding accounting for such distribution.  The observations that Lemurs 
occur in India, Madagascar and Africa led some to consider a contiguous 
landmass “Lemuria” linking these three landmasses.  Mesosaurus was a small 
reptile adapted to shallow brackish water.  The skeletons of these are found 
only in two localities : the Southern Cape province of South Africa and Iraver 
formations of Brazil. The two localities presently are 4,800 km apart with an 
ocean in between them. 
Botanical Evidence 
Presence of glossopteris vegetation in carboniferous rocks of India, Australia, 
South Africa, Falkland Islands (Overseas territory of UK), Antarctica, etc. can 
be explained on the basis of the fact that parts were linked in the past. 
Tillite deposits 
It is the sedimentary rock formed out of deposits of glaciers. The Gondwana 
system of sediments from India is known to have its counter parts in six 
different landmasses of the Southern Hemisphere. 
 
At the base the system has thick Tillite indicating extensive and prolonged 
glaciation. Counter parts of this succession are found in Africa, Falkland 
Island, Madagascar, Antarctica and Australia besides India. 
Overall resemblance of the Gondwana type sediments clearly demonstrates 
that these landmasses had remarkably similar histories. 
Placer Deposits 
Rich placer deposits of gold are found on the Ghana coast (West Africa) but 
the source (gold bearing veins) are in Brazil and it is obvious that the gold 
deposits of the Ghana are derived from the Brazil plateau when the two 
continents lay side by side. 
Force for Continental Drift 
Force for Drifting Wegener suggested that the movement responsible for the 
drifting of the continents was caused by pole-fleeing force and tidal force. The 
polar-fleeing force relates to the rotation of the earth. You are aware of the fact 
that the earth is not a perfect sphere; it has a bulge at the equator. This bulge is 
due to the rotation of the earth. The second force that was suggested by 
Wegener—the tidal force—is due to the attraction of the moon and the sun that 
develops tides in oceanic waters. Wegener believed that these forces would 
become effective when applied over many million years. However, most of 
scholars considered these forces to be totally inadequate. 
According to Wegener, the drift is still continuing. 
 
Drawbacks of Continental Drift Theory 
Wegener failed to explain why the drift began only in Mesozoic era and not 
before. 
The theory doesn’t take oceans into consideration. 
Proofs heavily depend on assumptions and are very general in nature. 
Page 4


 
CONTINENTAL DRIFT THEORY: 
INTRODUCTION: 
Continental drift describes one of the earliest ways geologists 
thought continents moved over time. Today, the theory of continental drift has 
been replaced by the science of plate tectonics.  
 
The speculation that continents might have 'drifted' was first put forward by 
Abraham Ortelius in 1596. The concept was independently and more fully 
developed by Alfred Wegener in 1912, but his theory was rejected by many for 
lack of any motive mechanism. 
  
The theory of continental drift is most associated with the scientist Alfred 
Wegener. In the early 20th century, Wegener published a paper explaining his 
theory that the continental landmasses were “drifting” across the Earth, 
sometimes plowing through oceans and into each other. He called this 
movement continental drift.  
  
Continental Drift Theory (Alfred Wegener, 1922) 
According to Wegener, all the continents formed a single continental mass, a 
mega ocean surrounded.  The super continent was named PANGAEA, which 
meant all earth. The mega-ocean was called PANTHALASSA, meaning all 
water. He argued that, around 200 million years ago, the super continent, 
Pangaea, began to split. Pangaea first broke into two large continental masses 
as Laurasia and Gondwanaland forming the northern and southern components 
respectively with Tethys sea . Subsequently, Laurasia and Gondwanaland 
continued to break into various smaller continents that exist today. 
Evidence in support of Continental Drift 
Physical Features 
The shorelines of Africa and South America facing each other have a 
remarkable and unmistakable match, especially, the bulge of Brazil fits into 
the Gulf of Guinea.Greenland seems to fit in well with Ellesmere and Baffin 
islands. The west coast of India, Madagascar and Africa seem to have been 
 
joined. North and South America on one side and Africa and Europe on the 
other fit along the mid-Atlantic ridge. The Caledonian and Hercynian 
mountains of Europe and the Appalachians of USA seem to be one continuous 
series. 
Rocks of Same Age Across the Oceans 
The radiometric dating methods developed in the recent period have facilitated 
correlating the rock formation from different continents across the vast ocean. 
The belt of ancient rocks of 2,000 million years from Brazil coast matches 
with those from western Africa.  The earliest marine deposits along the 
coastline of South America and Africa are of the Jurassic age. This suggests 
that the ocean did not exist prior to that time. 
Distribution of Fossils 
When identical species of plants and animals adapted to living on land or in 
fresh water are found on either side of the marine barriers, a problem arises 
regarding accounting for such distribution.  The observations that Lemurs 
occur in India, Madagascar and Africa led some to consider a contiguous 
landmass “Lemuria” linking these three landmasses.  Mesosaurus was a small 
reptile adapted to shallow brackish water.  The skeletons of these are found 
only in two localities : the Southern Cape province of South Africa and Iraver 
formations of Brazil. The two localities presently are 4,800 km apart with an 
ocean in between them. 
Botanical Evidence 
Presence of glossopteris vegetation in carboniferous rocks of India, Australia, 
South Africa, Falkland Islands (Overseas territory of UK), Antarctica, etc. can 
be explained on the basis of the fact that parts were linked in the past. 
Tillite deposits 
It is the sedimentary rock formed out of deposits of glaciers. The Gondwana 
system of sediments from India is known to have its counter parts in six 
different landmasses of the Southern Hemisphere. 
 
At the base the system has thick Tillite indicating extensive and prolonged 
glaciation. Counter parts of this succession are found in Africa, Falkland 
Island, Madagascar, Antarctica and Australia besides India. 
Overall resemblance of the Gondwana type sediments clearly demonstrates 
that these landmasses had remarkably similar histories. 
Placer Deposits 
Rich placer deposits of gold are found on the Ghana coast (West Africa) but 
the source (gold bearing veins) are in Brazil and it is obvious that the gold 
deposits of the Ghana are derived from the Brazil plateau when the two 
continents lay side by side. 
Force for Continental Drift 
Force for Drifting Wegener suggested that the movement responsible for the 
drifting of the continents was caused by pole-fleeing force and tidal force. The 
polar-fleeing force relates to the rotation of the earth. You are aware of the fact 
that the earth is not a perfect sphere; it has a bulge at the equator. This bulge is 
due to the rotation of the earth. The second force that was suggested by 
Wegener—the tidal force—is due to the attraction of the moon and the sun that 
develops tides in oceanic waters. Wegener believed that these forces would 
become effective when applied over many million years. However, most of 
scholars considered these forces to be totally inadequate. 
According to Wegener, the drift is still continuing. 
 
Drawbacks of Continental Drift Theory 
Wegener failed to explain why the drift began only in Mesozoic era and not 
before. 
The theory doesn’t take oceans into consideration. 
Proofs heavily depend on assumptions and are very general in nature. 
 
Forces like buoyancy, tidal currents and gravity are too weak to be able to 
move continents. This is illogical because for these factors to be able to cause 
a drift of such a magnitude, they will have to be millions of times stronger 
 
Coastlines are a temporary feature and are liable to change. Several other 
combinations of fitting in of landforms could be attempted. 
Similar sorts of  vegetation is also found in the northern parts like Afghanistan, 
Iran and Siberia and other  unrelated parts of the world. 
Rocks of same age and similar characteristics are found in other parts of the 
world too. 
CONCLUSION 
Modern theories (PT) accept the existence of Pangaea and related landmasses 
but give a very different explanation to the causes of drift. 
 
CONVECTIONAL CURRENT THEORY 
 Arthur Holmes in 1930s discussed the possibility of convection currents 
operating in the mantle portion. These currents are generated due to 
radioactive elements causing thermal differences in the mantle portion. 
Holmes argued that there exists a system of such currents in the entire mantle 
portion.  
Wherever rising limbs of these currents meet, oceanic ridges are formed on the 
sea floor and wherever the failing limbs meet, trenches are formed. 
 
 
 
 
 
 
Page 5


 
CONTINENTAL DRIFT THEORY: 
INTRODUCTION: 
Continental drift describes one of the earliest ways geologists 
thought continents moved over time. Today, the theory of continental drift has 
been replaced by the science of plate tectonics.  
 
The speculation that continents might have 'drifted' was first put forward by 
Abraham Ortelius in 1596. The concept was independently and more fully 
developed by Alfred Wegener in 1912, but his theory was rejected by many for 
lack of any motive mechanism. 
  
The theory of continental drift is most associated with the scientist Alfred 
Wegener. In the early 20th century, Wegener published a paper explaining his 
theory that the continental landmasses were “drifting” across the Earth, 
sometimes plowing through oceans and into each other. He called this 
movement continental drift.  
  
Continental Drift Theory (Alfred Wegener, 1922) 
According to Wegener, all the continents formed a single continental mass, a 
mega ocean surrounded.  The super continent was named PANGAEA, which 
meant all earth. The mega-ocean was called PANTHALASSA, meaning all 
water. He argued that, around 200 million years ago, the super continent, 
Pangaea, began to split. Pangaea first broke into two large continental masses 
as Laurasia and Gondwanaland forming the northern and southern components 
respectively with Tethys sea . Subsequently, Laurasia and Gondwanaland 
continued to break into various smaller continents that exist today. 
Evidence in support of Continental Drift 
Physical Features 
The shorelines of Africa and South America facing each other have a 
remarkable and unmistakable match, especially, the bulge of Brazil fits into 
the Gulf of Guinea.Greenland seems to fit in well with Ellesmere and Baffin 
islands. The west coast of India, Madagascar and Africa seem to have been 
 
joined. North and South America on one side and Africa and Europe on the 
other fit along the mid-Atlantic ridge. The Caledonian and Hercynian 
mountains of Europe and the Appalachians of USA seem to be one continuous 
series. 
Rocks of Same Age Across the Oceans 
The radiometric dating methods developed in the recent period have facilitated 
correlating the rock formation from different continents across the vast ocean. 
The belt of ancient rocks of 2,000 million years from Brazil coast matches 
with those from western Africa.  The earliest marine deposits along the 
coastline of South America and Africa are of the Jurassic age. This suggests 
that the ocean did not exist prior to that time. 
Distribution of Fossils 
When identical species of plants and animals adapted to living on land or in 
fresh water are found on either side of the marine barriers, a problem arises 
regarding accounting for such distribution.  The observations that Lemurs 
occur in India, Madagascar and Africa led some to consider a contiguous 
landmass “Lemuria” linking these three landmasses.  Mesosaurus was a small 
reptile adapted to shallow brackish water.  The skeletons of these are found 
only in two localities : the Southern Cape province of South Africa and Iraver 
formations of Brazil. The two localities presently are 4,800 km apart with an 
ocean in between them. 
Botanical Evidence 
Presence of glossopteris vegetation in carboniferous rocks of India, Australia, 
South Africa, Falkland Islands (Overseas territory of UK), Antarctica, etc. can 
be explained on the basis of the fact that parts were linked in the past. 
Tillite deposits 
It is the sedimentary rock formed out of deposits of glaciers. The Gondwana 
system of sediments from India is known to have its counter parts in six 
different landmasses of the Southern Hemisphere. 
 
At the base the system has thick Tillite indicating extensive and prolonged 
glaciation. Counter parts of this succession are found in Africa, Falkland 
Island, Madagascar, Antarctica and Australia besides India. 
Overall resemblance of the Gondwana type sediments clearly demonstrates 
that these landmasses had remarkably similar histories. 
Placer Deposits 
Rich placer deposits of gold are found on the Ghana coast (West Africa) but 
the source (gold bearing veins) are in Brazil and it is obvious that the gold 
deposits of the Ghana are derived from the Brazil plateau when the two 
continents lay side by side. 
Force for Continental Drift 
Force for Drifting Wegener suggested that the movement responsible for the 
drifting of the continents was caused by pole-fleeing force and tidal force. The 
polar-fleeing force relates to the rotation of the earth. You are aware of the fact 
that the earth is not a perfect sphere; it has a bulge at the equator. This bulge is 
due to the rotation of the earth. The second force that was suggested by 
Wegener—the tidal force—is due to the attraction of the moon and the sun that 
develops tides in oceanic waters. Wegener believed that these forces would 
become effective when applied over many million years. However, most of 
scholars considered these forces to be totally inadequate. 
According to Wegener, the drift is still continuing. 
 
Drawbacks of Continental Drift Theory 
Wegener failed to explain why the drift began only in Mesozoic era and not 
before. 
The theory doesn’t take oceans into consideration. 
Proofs heavily depend on assumptions and are very general in nature. 
 
Forces like buoyancy, tidal currents and gravity are too weak to be able to 
move continents. This is illogical because for these factors to be able to cause 
a drift of such a magnitude, they will have to be millions of times stronger 
 
Coastlines are a temporary feature and are liable to change. Several other 
combinations of fitting in of landforms could be attempted. 
Similar sorts of  vegetation is also found in the northern parts like Afghanistan, 
Iran and Siberia and other  unrelated parts of the world. 
Rocks of same age and similar characteristics are found in other parts of the 
world too. 
CONCLUSION 
Modern theories (PT) accept the existence of Pangaea and related landmasses 
but give a very different explanation to the causes of drift. 
 
CONVECTIONAL CURRENT THEORY 
 Arthur Holmes in 1930s discussed the possibility of convection currents 
operating in the mantle portion. These currents are generated due to 
radioactive elements causing thermal differences in the mantle portion. 
Holmes argued that there exists a system of such currents in the entire mantle 
portion.  
Wherever rising limbs of these currents meet, oceanic ridges are formed on the 
sea floor and wherever the failing limbs meet, trenches are formed.