Lecture 2 - Geologic Time Scale

Question 1

what is a stratigraphic column?

Answer 1

represents all the eras as if they were all one top of one another (not realistic tho)

Question 2

Ma / Ga

Answer 2

mega-annum (millions)

giga-annum (billions)

Question 3

how long did the HADEAN eon last for?

Answer 3

4.56Ga to 4.0Ga

Question 4

anything interesting in the Hadean?

Answer 4

oldest meteorites found @ 4.56Ga

no rock records until v end of the Hadeon

life PROBABLY originated at this time

Question 5

how long did the ARCHEAN Eon last for?

Answer 5

4.0 to 2.5Ga

Question 6

what’s special about the Archean Eon?

Answer 6

FIRST ROCK RECORD from Acasta Greiss (NW territories)

Question 7

stromatolites

Answer 7

first fossil evidence of life; a TRACE fossil (indicates activity of organism)

mound shape sediments locked into place by cyanobaterica

Question 8

cyanobacteria

Answer 8

photosynthesizable bacteria

oxygenated earth’s atmosphere

Question 9

How long did the PROTERZOIC eon last for?

Answer 9

2.5Ga to 541Ma

Question 10

anything special during Proterozoic?

Answer 10

development of eukaryotic and multicellular life forms

diversifying

mostly soft bodied organisms, fossil impressions found in sandstone (burrowing)

Question 11

Ediacaran period

Answer 11

end of the proterozoic, first point where multicellular life developed

Question 12

Cambrian explosion

Answer 12

~535Ma

bunch of fossilised life found due to the origin of hard parts

Question 13

What are the three eons in the Phanerozoic Eon?

Answer 13

Paleozoic, Mesozoic, Cenazoic

Question 14

permian extinction

Answer 14

happened in the Paleozoic

Pangaea is assembled, amount of habitat reduced

Question 15

how long did the paleozoic last?

Answer 15

541Ma to 252Ma

Question 16

what kind of things developed in the paleozoic?

Answer 16

land plants

amphibians

reptiles

Question 17

Mesozoic Era

Answer 17

201Ma to 66Ma

“Age of Reptiles”

Question 18

Cenozoic Era

Answer 18

66Ma after asteroid
“Age of Mammals”

small animals that survived

monotremes (egg laying mammals) and all other mammals

Question 19

what are the two periods of the Cenozoic?

Answer 19

tertiary (paleogene, neogene)

and then quaternery (Pleistocene, Hologene)

Question 20

K/Pg extinction

Answer 20

Cretaceous/Paleogene DINOS DIE CAUSE OF ASTEROID