geologic eras

Question 1

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

Answer 1

• precambrian
• paleozoic
• mesozoic
• cenozoic

Question 2

when was the canadian shield formed?

Answer 2

the precambrian era

Question 3

when were the appalachian mountains formed?

Answer 3

the paleozoic era

Question 4

when were the rocky and innuitian mountains formed?

Answer 4

the mesozoic era

Question 5

when were the rocky mountains completely formed?

Answer 5

the cenozoic era

Question 6

how long ago was the precambrian era?

Answer 6

4600-570 million years ago

Question 7

how long ago was the paleozoic era?

Answer 7

570-245 million years ago

Question 8

how long ago was the mesozoic era?

Answer 8

245-66 million years ago

Question 9

how long ago was the cenozoic era?

Answer 9

66 million years ago-present

Question 10

when were the first single organisms evolved?

Answer 10

the precambrian era

Question 11

when were the first multi-celled organisms evolved?

Answer 11

the precambrian era

Question 12

when were the first plants and animals evolved?

Answer 12

the paleozoic era

Question 13

when were the first fish, insects and amphibians evolved?

Answer 13

the paleozoic era

Question 14

when did the first mammals and birds evolve?

Answer 14

the mesozoic era

Question 15

when did the first flowering plants evolve?

Answer 15

the mesozoic era

Question 16

when did modern mammals take over the earth?

Answer 16

the cenozoic era

Question 17

when did the human age begin?

Answer 17

the cenozoic era

Question 18

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

Answer 18

the precambrian era

Question 19

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

Answer 19

the paleozoic era

Question 20

when were shallow seas inside north america?

Answer 20

the mesozoic era

Question 21

when did earth first have a stabilized atmosphere?

Answer 21

the mesozoic era

Question 22

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

Answer 22

the mesozoic era

Question 23

when did pangaea break up?

Answer 23

the cenozoic era

Question 24

when do ice ages occur, currently?

Answer 24

about every 100 000 years