Question

haping Earth



Scientists claim that all of the land on Earth was once one continent named Pangea (Pangaea). The current shape and location of the continents is a direct result of the movement of the tectonic plates, upon which the continents and oceans sit. The movement of the plates shifted land masses, which has resulted in the location of the continents today. The diagram shows the movement of the continents over time.







Tectonic plate boundaries are the locations where two plates meet. Plate boundaries can be located on coastlines, such as the west coast of the North American and South American plates. Plate boundaries can be located in the middle of oceans, like in the Pacific plate. Plate boundaries can also occur over land, like the Eurasian plate. The diagram shows the seven major tectonic plates.







Convection currents in Earth's mantle cause the lithosphere (plates) to move. At the border of two plates, the plates can move in different ways: together, apart, or alongside each other. When continental plates slowly collide with one another, mountains can be formed. When plates slide past or alongside one another, an earthquake can occur.



When plates move apart, new oceanic crust is formed when magma escapes where the plates separate. Oceanic ridges are formed where the magma escapes and cools. The diagram shows the formation of an oceanic ridge.







When plates move together, one can slide under or over the other. The oceanic plate is more dense than the continental plate so it sinks below. This can form an oceanic trench as shown.







Geologists have discovered that rocks in the Appalachian Mountains of North America are the same as the rocks in the Caledonian Mountains of Europe.

Which TWO things do the rocks provide evidence of in terms of the geologic understanding of Earth?


Plate motions have occurred in the past.


Ocean currents have moved rocks over time.


Rocks from the same geologic time period are the same.


Sections from different continents were once connected.


Certain types of rocks can only be found in certain environments

Answer 1

- Plate motions have occurred in the past.
- Sections from different continents were once connected.

Explanation: identical rock sequences on separate continents indicate those landmasses were once joined and later moved apart by plate tectonics.