Palaeogeography and Plate Tectonics Flashcards
(75 cards)
What was the supercontinent called?
Pangaea
Who was the German researcher who first proposed that the continents used to be connected into one?
Alfred Wagner
What evidence did alfred wagner use to form his hypothesis?
The east coast of South America and West coast of Africa seemed to share a similar shape; there were also overlaps in fossilized specimens in these two regions that would not have been able to swim.
What was Wegener missing when he first suggested that there used to be a supercontinent?
He was able to show by which mechanism the Continents moved?
What is the outermost layer of the earth that consists of continents and ocean basins?
The crust
How deep is the crust?
Between 5 and 25 km deep
What is the layer of the earth that is below the crust?
The mantle
How deep is the mantle?
The mantle layer is over 2,500 km deep.
What is the uppermost portion of the mantle + the crust called?
The lithosphere
What is the layer below the lithsphere of the mantle called?
The Asthenosphere
What are the differences between the asthenosphere and the lithosphere?
The lithosphere is rigid and solid, the asthenosphere is viscous and flows
What is below the mantel in the earth? What is it made of?
The core that is made of iron and nickel
What are the two layers of the core?
The outer core which is made of molten liquid, and the inner core that is a solid ball, the inner core is estimated to be as hot as the surface of the sun
What causes currents in the asthenoshpere?
The high internal temperatures of the earth
What do the asthenosphere currents do?
They move plates/pieces of the lithosphere around causing them to move
How does the lithosphere move?
The viscous asthenosphere and currents that it experiences move the lithosphere plates, slowly overtime the lithosphere also sinks into the asthenosphere and gets heated while part of the asthenosphere gets exposed to the colder outer temperatures and solidifies
What is the movement of the Lithosphere called?
Plate Tectonics
What are the three natural events/formations that can come of two tectonic plates colliding?
Earthquakes, Volcanoes, or Mountains
What did the earth look like at the start of the triassic?
It was still a single supercontinent - Pangea
What was the name of the super ocean that coincided with pangaea?
Panthalassa
Why were dinosaurs quite similar all over the planet throughout the late Triassic and early Jurassic?
There were no major sea barriers preventing the same dinosaurs form moving and occupying all the land.
What formations porvide evidence for dinosaurs being similar in different parts of the world during the jurassic?
The Morrison Formation, The Tendaguru Formation (Tanzania) and the Lourinha Formation (Portugal)
When did the first true sauropods appear?
Late Triassic
When did sauropods surpass prosauropods in abundance and body size?
The early Jurassic