Science 10 Class Notes - Earth Layers, Plate Tectonics, and Early Earth History

A set of practice flashcards covering Earth's layers, discontinuities, lithosphere/asthenosphere, plate tectonics, Pangaea, Panthalassa, and early Earth fossils as presented in the notes.

What are the four main Earth layers listed in the notes?

Crust, Mantle, Outer Core, Inner Core.

What is the Mohorovičić discontinuity?

The boundary between the crust and the mantle.

What is the Gutenberg discontinuity?

The boundary between the mantle and the outer core.

What is the Lehmann discontinuity?

The boundary between the outer core and the inner core.

What does the lithosphere consist of?

The crust and the uppermost part of the mantle.

What is the asthenosphere?

The mantle layer beneath the lithosphere made of hot, molten rocks that can deform due to convection.

What is the approximate thickness of the Earth's crust as listed in the notes?

5–70 km.

What is the approximate thickness of the mantle as listed in the notes?

About 2900 km.

What is the approximate thickness of the outer core as listed in the notes?

About 2270 km.

What is the approximate thickness of the inner core as listed in the notes?

About 1220 km.

What causes convection currents in the Earth's interior?

Heat-driven movement of mantle materials that can deform the crust, lithosphere, and mantle.

What is a divergent boundary?

A boundary where tectonic plates move apart.

What is a convergent boundary?

A boundary where tectonic plates move toward each other.

What is Pangaea?

A massive supercontinent that united nearly all Earth’s landmasses into one block.

What do the terms 'pan' and 'gaea' mean in Pangaea?

Pan means 'all' and gaea means 'Earth'.

What is Panthalassa?

The vast global ocean surrounding Pangaea; means 'all seas.'

Which fossils are cited as evidence for continental drift in the notes?

Lystrosaurus and Glossopteris.

What is Lystrosaurus?

A dog-sized burrower that evolved about 270 million years ago (used as evidence for continental drift).

What is Glossopteris?

A prevalent seed fern from the Permian and Triassic periods, used as evidence for continental drift.

Which continents were part of Pangaea according to the notes?

Africa, India, Antarctica, Australia, South America, North America, Eurasia.

What does 'Pangaea' mean?

All Earth (pan = all, gaea = Earth).

What is Panthalassa?

The vast ocean surrounding Pangaea; means 'all seas.'