Vocab
These organisms are single-celled autotrophs made of silica
What are diatoms?
Hydrothermal vents are also sometimes called this
What are deep sea hot springs?
Continental shelf makes up approximately this percentage of total ocean area
What is 7%?
Hydrothermal vents were discovered in this year
What is 1977?
A continental shelf ends at this point
What is a shelf break?
The supercontinent Laurasia consisted of:
What is 1) North America and 2) Asia?
Give an example of an active continental margin
What is 'the west coast of the US, the west coast of South America?'
These are described as boundaries between oceanic and continental crust
What are continental margins?
These are microscopic heterotrophs with shells made of calcium carbonate
What are Foraminiferans?
These organisms are single-celled heterotrophs with shells made of silica
What are Radiolarians?
This type of sediment is derived from the chemical and physical breakdown of rocks
What is lithogenous sediment?
This type of sediment is made up of microfossils
What is biogenous sediment?
The supercontinent Gondwana was made up of:
What are 1) S. America, 2) Africa, 3) India, 4) Australia, 5) Antarctica?
These are single-celled autotrophs made up of calcium carbonate plates
What are Coccolithophorids?
This part of the continental margin can be thought of as an underwater river delta made of sediment
What is the continental rise?
What are 1) continental shelf, 2) continental slope, and 3) continental rise?
These areas are where trenches are formed
What are convergent boundaries/subduction zones?
Briefly explain what a continental slope is
What is 'a continental slope can be thought of as the edge of a continent; begins at shelf break and extends to the sea floor; usually very steep?'
Compare what occurs when two continental plates collide versus two ocean plates
What is 'when two continental plates collide, a mountain range forms; when two oceanic plates collide, many things can happen including formation of a trench, volcanoes, earthquakes, etc?'
At regular intervals, mid-ocean ridges are displaced by this
What are 'transform faults?'
Briefly explain how hydrothermal vents form?
What is 'near mid-ocean ridges, seawater slowly percolates down through the crust through cracks and pores; the water is heated by the magma below and picks up many minerals/nutrients in this chemical heating (especially sulfates); this water is then forced through the crust back to surface at approx 750 F - when this water hits the much cooler ocean water, these minerals precipitate out of solution and form the chimney structures associated with hydrothermal vents?'
If sea floor is always being created, why does the size of the Earth not increase?
What is 'because as sea floor is being created, it is also being destroyed/subducted at approximately the same rate?'
Briefly explain why marine sediments are important clues to the past
What is 'because marine sediments tell us about the climate conditions and natural history of earth at points during the past - allows us to reconstruct a lot of our planet's history?'
List and briefly explain the three major types of plate boundaries
What are 1) convergent boundaries - plates colliding; 2) divergent boundaries - plates moving away from each other, 3) transform boundaries - plates moving past each other?
What is different/significant about lithogenous sediments
What is 'they only come from continental crust so they give us a very specific way to reconstruct earth's terrestrial history?'