geologic eras Flashcards Preview

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Flashcards in geologic eras Deck (24)
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1
Q

what are the four eras, from the past to the present

A
  • precambrian
  • paleozoic
  • mesozoic
  • cenozoic
2
Q

when was the canadian shield formed?

A

the precambrian era

3
Q

when were the appalachian mountains formed?

A

the paleozoic era

4
Q

when were the rocky and innuitian mountains formed?

A

the mesozoic era

5
Q

when were the rocky mountains completely formed?

A

the cenozoic era

6
Q

how long ago was the precambrian era?

A

4600-570 million years ago

7
Q

how long ago was the paleozoic era?

A

570-245 million years ago

8
Q

how long ago was the mesozoic era?

A

245-66 million years ago

9
Q

how long ago was the cenozoic era?

A

66 million years ago-present

10
Q

when were the first single organisms evolved?

A

the precambrian era

11
Q

when were the first multi-celled organisms evolved?

A

the precambrian era

12
Q

when were the first plants and animals evolved?

A

the paleozoic era

13
Q

when were the first fish, insects and amphibians evolved?

A

the paleozoic era

14
Q

when did the first mammals and birds evolve?

A

the mesozoic era

15
Q

when did the first flowering plants evolve?

A

the mesozoic era

16
Q

when did modern mammals take over the earth?

A

the cenozoic era

17
Q

when did the human age begin?

A

the cenozoic era

18
Q

when did cratons (large land masses) form due to volcanic activity?

A

the precambrian era

19
Q

when was most of north america covered in warm, shallow seas?

A

the paleozoic era

20
Q

when were shallow seas inside north america?

A

the mesozoic era

21
Q

when did earth first have a stabilized atmosphere?

A

the mesozoic era

22
Q

when did large reptiles dominate the earth until a major extinction event?

A

the mesozoic era

23
Q

when did pangaea break up?

A

the cenozoic era

24
Q

when do ice ages occur, currently?

A

about every 100 000 years