lecture 1 brief history of earth

Question 1

when and how did earth form

Answer 1

4.56 billion years ago through rapid condensation of a dust cloud that circulated around the young sun

Question 2

when are the oldest rocks on the earths surface from

Answer 2

4.3 billion years ago

Question 3

when did the moon form and earths core seperate

Answer 3

4510Ma

Question 4

what was the atmosphere 4510Ma

Answer 4

N2 H2O CO2

Question 5

how old are the oldest lunar rocks

Answer 5

4470Ma

Question 6

when was the hadean eon and what was it like

Answer 6

4600Ma to 4000Ma

hot fiery, earth is formed here, evidence of some liquid water and a felsic crust

Question 7

when was the earliest evidence of water erosion (showing presence of hydrosphere)

Answer 7

3800Ma

Question 8

how was the hydrosphere started

Answer 8

outgassing of volcanos

Question 9

when where the microfossils of the earliest primative bacteria from

Answer 9

3500Ma

Question 10

what did the first primative bacteria cause?

Answer 10

the start of the rise in atmospheric oxygen

Question 11

what where the earliest primative bacteria

Answer 11

hypothermic chemoautotrophs

Question 12

what did rocks found from 3500Ma show

Answer 12

geo dynamo is operational as rocks showed similar magnetism to today

Question 13

when where the first banded iron formations formed?

Answer 13

2700Ma

Question 14

when was continental formation complete

Answer 14

2500Ma

Question 15

when was the archean eon and what was it like

Answer 15

4000Ma to 2500Ma

crust cooled continent formed, single celled organisms emerged

Question 16

when did the first multicellular organisms come about

Answer 16

580Ma

Question 17

what also occured with the first multicelular organisms

Answer 17

oxygen reached 21% of the atmosphere

Question 18

what and when was the “evolutionary big bang”?

Answer 18

542Ma

8 new branches of the animal kingdom formed

Question 19

when where the first organisms with shells around

Answer 19

542Ma

Question 20

when were the first land animals

Answer 20

420Ma

Question 21

when was the proterozoic eon and what was it like

Answer 21

2500Ma to 541Ma

oxygen but not a lot of life

Question 22

when were the earliest flowering plants

Answer 22

125Ma

Question 23

when were the first hominoids

Answer 23

5Ma

Question 24

when were the first homosapiens

Answer 24

0.2Ma

Question 25

when is the phanerozoic eon and what is it like

Answer 25

541Ma to now

we are in it, there is life, started with cambrian explosion

Question 26

when were the five mass extinctions (followed by evolutionary radiation)

Answer 26

434Ma
359Ma
251MA
200Ma
65Ma

Question 27

what is gravitational diferentiation

Answer 27

the transformation of random chunks of premordial matter into a body ehosr interior is divided into concentric layers that differ from one another chemicahally and physically