Evidence of Plate Tectonics/ Theories

Question 1

Describe a timeline of the main people/ process involved in tectonic theories?

Answer 1

1600’s World Maps were created of the Atlantic ocean and it became clear that South America and Western Africa were once connected. FRANCIS BACON

1912- ALFRED WEGNER proposed and published continental drift theory, based on Pangea

1950- Submarines used to track the ocean floor- Mid Atlantic Ridge discovered

1960’s- Harry Hammond Hess= “The History of The Ocean Basins”= sea floor spreading and continental drift

Question 2

What is palaeomagnetism?

Answer 2

The study of the changes in the Earth’s magnetic field over time.

Approx. every 4000 years the magnetic field has a polarity reversal= “stripes” as it moves from N to S poles.

Question 3

How does sea floor spreading/ palaeomagnetism take place?

Answer 3

This is the alternating Polarity of rocks

IRON particles in lava which are magnetic are erupted and they align with the earth’s magnetic field= STRIPES

Question 4

What Geological Evidence is there of Plate Movements?

Answer 4

Continental Fit- the “jig-saw fit of South America and West Africa
Areas where geological structures match across the African and Arabian plates
The discovery of late carboniferous glacial deposits in South America.

Question 5

What Biological Evidence is there of plate movements?

Answer 5

Fossil remains of the Mesosaurous in both South America and Southern Africa= unlikely they migrated across the Atlantic

Fossil brachiopods found in Indian Limestone are comparable with similar ones found in Australia