To justify his continental drift theory, Alfred Wegner Marshalled an impressive amount of evidence, facts and opinions, most of which have proved too true to be denied.  Other researchers have added on the amount of evidence.

Geometrical fitting (jig – saw /visual fit).

The present of continental margins is such that most of the continents have geometric shapes that would fit into each of forced close.  Thus jig – saw fit of continents were at one time together forming Pangea but they merely split to other parts eg fitting the Eastern coast  of South America in the West Africa.

 Geological similarities.

Similarity on rocks is another evidence used to justify continental drift.  There are remarkable similarities between rocks found in different landmasses of the southern continents.  In Africa the rocks of Ghana and Cameroon  share common characteristics with those of Brazil on South America.  It therefore suggests that those areas were once  of the same continent.  This evidences constituents what is commonly known as “matching geology”.

Presence of fold mountains.

This seems to suggest that continents have been moving towards each other because when the tectonic plates collide with other,  land masses on them may  fold and lead to the formation of fold mountains.  Atlas and Alps ranges, Himalayas in India due to collision of the Indian Sub continent and the Laurasia rock.

Paleotological Evidence(Historical Fossils).

The existence of historical fossils and other rock types where climatic conditions do not favour theory  formation also suggests that continental drift took place.  The following are the examples: In the Greenland, there is coral rock development while develops only on tropical regions with warm conditions.

In the same way, rocks of Greenland, there are Lichans and swamps of tropical trees embedded within the rocks.  There are also bones of tropical animals in the rocks all of which prove that Green land could be in the tropical region but later lifted.

Furthermore, the existence of Petroleum, coal and other organic minerals in the extreme Northern Hemisphere as an indication of continental drift.  This is because coal, petroleum are meant for tropical areas.

Vegetation.

The similarity of the vegetation and animals in different continents, which seem to have been attached to each other suggests the occurrence  of continental drift, eg the Brazilian tropical rainforests and the Congo basin.  Rain forests also suggest that those regions must have been attached together one time.

Occurrence of Laterite.

The occurrence of Laterite on North America and certain parts of Europe shows that those regions once upon a time enjoyed tropical  climatic conditions which were conducive for the formation of Laterites.

Dwyka Tillites:

Studies from Palaeclimatology have provided further evidence that justifies continental drift.  This is in convection with glacial deposits.  Dwyka Tillites are the glacial carboniferous rocks are found on many parts of the former Gondwanaland which proves that these continents were once together.

Palaegmanetism evidence.

Palemagnetism refers to the ancient or fossils  magnetism on rocks.  It is established  from the geological laboratory that research or rocks of the earth crust which are always magnetized by the earth’s magnetic field at the time of  formation.  They show real North and  South.

Magnetic Field Reversals

In 1963, British scientists Fred J. Vine and Drummond H. Matthews combined their observations of the marine magnetic anomalies with the concept of reversals of the earth’s magnetic field. They proposed that the marine magnetic anomalies were a “tape recording” of the spreading of the ocean floor as the earth’s magnetic field reversed its direction. At the same time, other geophysicists were studying lava flows from many parts of the world to see how these flows revealed the record of reversals of the direction of the earth’s magnetic field. These studies showed that nearly four reversals have occurred over the past 5 million years. The concept of magnetic field reversals was a breakthrough that explained the magnetic polarity switches seen in seafloor spreading as well as the concept of similar magnetic patterns in the rocks used to demonstrate continental drift.

However when Pangea split up, the rock changed position and the direction of the magnetic north of the individual pieces of rock changed.

Sea floor spreading evidence:

Research has sown that most sea floors are expanding and many oceans and seas are becoming bigger.  This is probably because of the movement of continents eg the Red sea enlarged to 300 km wide in the 200 million years.  The ocean ridges on the middle oceans are reported to be expanding eg the Great Atlantic ridge is said to be expanding  and the Atlantic ocean’s enlarging

Expansion of the E. African Rift valley and the Jordan Valley.

The E. African rift valley is expanding proving that continents are in the state of motion as a result of compressional and tensional forces within the earth’s crust.  About 1000 million years the rift valley was not there.  It widens at a rate of about 2 – 3 cm/ year.

Similarity of oil beds.

It has been found out that the oil beds of Brazil are the same as those of Angola .  This has been an indicator that Angola and Brazil the must have been one geological unit with common oil beds that drifted apart from each other carrying along with it once shared oil beds  among others

Criticisms of evidence of continental drift.

Some researchers have given different views discrediting the contribution of Wegner and people who contributed to the theories of continental drift.  They argue that:

1.     The spreading of ocean floors might be because of continuous erosion of the mainland, which makes the oceans appear as if they are expanding.

2.     The similarity in the rocks might because of the same climatic conditions eg Equatorial climatic for the case of Brazil and Congo.

3.     The presence of coral rock on different continents and the existence of identical vegetation on different continents might be because f the increasing world temperatures.

4.     The presence of glacial tillites material on the Congo Basin and the Karoon basin might be because there existed very high mountains on those regions and they were covered by snow.  But with time, snow was eroded down those mountains through glaciation leaving behind glacial deposits.

5.     The above criticisms show that there are some weaknesses on theories of Wegner.  However some are real and therefore the theory should not be under estimated.