Terre + Espace

Question 1

how are sedimentary layers formed?

Answer 1

the deposits of sediments in a body of water that slowly become sedimentary rocks and slowly gain layers.

Question 2

how can you tell if a layer of sediment is from the same time

Answer 2

color, similar/same mineral, size of particles.

Question 3

what is the “law” of sedimentary layers? what is it called?

Answer 3

superposition = the newer rocks are always deposited ON TOP of older rocks.

Question 4

what is the most recent mass extinction. what happened?

Answer 4

in the cretaceous period a HUGE meteor made contact with earth, causing lots of dust in the air and stopped sunlight which led to a much lower climat and no photosynthesis. the caused the extinction of dinosaurs , animals, vegetal life and half of marine life.

Question 5

what is the second most recent mass extinction. what happened?

Answer 5

in the ‘trias’ period volcanic activity caused the release of huge amounts of C02 and methane, leading to global warming and the disappearance of big amphibians and 20% of marine species.

Question 6

what is the third most recent mass extinction. what happened?

Answer 6

in the permien period large amount of volcanic eruptions caused the release of a lot of C02 in the air, leading to global ASWELL as a meteorite that hit earth. this caused the extinction of 70% of terrestrial species as well as 90% of marine species. = largest extinction in the world.

Question 7

what is the fourth most recent extinction. what happened?

Answer 7

in the devonian period an ocean glaciation killed 70% of marine species.

Question 8

what is the fifth most recent extinction. what happened?

Answer 8

in the ordovician period, an ocean glaciation as well as the explosion of a star caused the extinction of 70% of marine species.

Question 9

what are the conditions favorable to life?

Answer 9

1. is comprised of cells
2. responds to stimuli
3. preforms exchanges with its middle
4. thinks and develops
5. uses energy
6. reproduces
7. adapts to change.

Question 10

what is a fossil?

Answer 10

trace of life conserved in the earth’s crust

Question 11

what is the process of forming a fossil?

Answer 11

1 - body falls into water
2 - soft tissu decomposes
3 - the rest are petrified by dissolved minerals
4 - the rests are covered by sediments
5 - after ‘lithification’ of sediments, the rests become rock also, a rock in the shape of the body.

Question 12

what are the four types of fossils?

Answer 12

• petrified (rock)
• molded (the rock is formed around or in the rests, which decomposes after)
• trapped (rests are trapped in amber/ice, protected from decomposing
• prints (in mud that solidifies)