Continent Locations in the Past and Present

Question

The maps show the locations of continents at different times in Earth’s past.

There are five maps of the Earth's continents. The first map, labeled '250 million years ago', shows the continents joined together. The second map, labeled '200 million years ago', shows a small gap between the northern and central continents and another small gap between the central and southern continents. The third map, labeled '145 million years ago', shows the continents moving further apart. The fourth map, labeled '65 million years ago', shows a further separation between South America and Africa. The fifth map shows the continent locations at present day.

Constructed Response Question
This map shows the present-day locations of some of the continents. The shaded sections in South America and Africa represents two areas where similar sequences and ages of rocks are present.

A. Explain why similar rock sequences and ages support the claim that the continents have moved over time.

Similar rock sequences and ages across continents provide strong evidence for the continental drift, which shows that continents were once connected and have since moved apart.

Constructed Response Question
B. Look at the map of the location of continents 200 million years ago. Based on the map, identify which continent would be the most likely place to find rock sequences and ages similar to these, and explain why.

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Answer 1

B. Based on the map of the continents 200 million years ago, the continent that would be the most likely place to find rock sequences and ages similar to those in South America and Africa is the continent of Antarctica.

The reason for this similarity lies in the theory of continental drift, which posits that all continents were once joined together in a supercontinent known as Pangaea. At that time, the landmasses that would become South America, Africa, and parts of Antarctica were physically connected. As the continents drifted apart, they retained some geological features, including similar rock sequences and ages.

Specifically, the rock formations in South America and Africa are often found to have matching characteristics, such as mineral composition, fossil types, and the timing of geological events. Given that Antarctica was also once adjacent to both South America and Africa, it is very likely that the rock sequences there share similarities due to their shared geological history before the continents separated.