Pangaea Supercontinent

Panthalassa- Ancient Super Ocean

245 million years ago Pangaea was the supercontinent that existed and is Greek for “all Earth”. Panthalassa was the super ocean of this time. Notice that none of the lands had ice on them. The majority of the land mass was centered around the equator.

Pangaea Breakup into Laurasia and Gondwanaland

180 million years ago Because of continental drift (tectonic plate shifting) Pangaea gradually broke apart forming Laurasia and Gondwana. Laurasia being the northern hemisphere and Gondwana being the southern hemisphere.

Continental Drift of Pangaea

65 million years ago By this time the continents had drifted into the basic form they are today.

Why are similar plant and animal fossils found on different continents?

65 million years ago But how were the continents able to drift apart being as heavy as they are? Our land masses seem rather solid and inflexible.

6 Layers of our Earth Continental Crust- land on which we live. Lighter than oceanic crust. Oceanic Crust- land under the oceans. Heavier than the continental crust because of the ocean water pressure on top of it and the heavy metals that get washed into it with no way out. Lithosphere- Made of continental/oceanic crust and land in depth from the surface to about 60 miles deep. It is a rigid land structure.

6 Layers of our Earth Asthenosphere- is area of Earth that is made up of molten lava and is considered to be plastic (not totally molten or totally solid). Lies from 60 miles to 430 miles below the Earth’s surface. Mesosphere- is the area of the Earth that is from 430 miles to 1800 miles below the surface. It is rigid.

6 Layers of our Earth Outer Core- is the area of the Earth that is from 1800 miles to 3200 miles below the surface. It is liquid. Inner Core- is the area of the Earth that is from 3200 miles to 3963 miles(center of the Earth). It is rigid and is made mostly of iron and nickel.

Plate Tectonic Theory States the Earth’s lithosphere is divided up into tectonic plates that move around on top of the Asthenosphere. All tectonic plates come in contact with other tectonic plates in areas called boundaries. There are three types of boundaries.

Plate Tectonic Theory Convergent boundary- two tectonic plates crash together. This is how mountains of the Himalayas and the Andes were formed. Divergent boundary- two tectonic plates pull apart from one another. This is how the Mid-Atlantic Ridge was formed. Transform boundary- two tectonic plates slide past each other. This is an example of the San Andreas Fault is California.