Geological Timescale

Question 1

record of the life forms and geological events in Earth’s history

Answer 1

Geological time scale

Question 2

scientists developed the time scale by studying what?

Answer 2

rock layers and fossils

Question 3

helps determine the absolute divisions in the time scale

Answer 3

Radioactive dating

Question 4

largest sections are called?

Answer 4

eons

Question 5

eons are divided into?(the 2nd largest section)

Answer 5

eras

Question 6

are divided “periods”

Answer 6

eras

Question 7

are divided into “epochs”

Answer 7

periods

Question 8

what are the two eons

Answer 8

Cryptozoic eon and Phanerozoic eon

Question 9

what are the major eras?

Answer 9

archean, proterozoic,pleozoic,mesoozoic,cenozoic

Question 10

How is time divided?

Answer 10

because a major organism went extinct in each section.

Question 11

540-4600 mya, oldest and longest

Answer 11

cryptozoic eon

Question 12

2500-4600 mya, earliest plants

Answer 12

archean era

Question 13

540-2500 mya, glaciations

Answer 13

proterozoic era

Question 14

540 mya - present, divided into three eras

Answer 14

paleozoic era, mesozoic era, cenozoic era

Question 15

middle life

Answer 15

mesozoic era

Question 15

past life

Answer 15

paleozoic era

Question 16

present life

Answer 16

cenozoic era

Question 17

570-250 mya, divided into 6 periods, organisms had hard parts

Answer 17

paleozoic era

Question 18

250-65 mya, time of reptiles

Answer 18

mesozoic era

Question 19

65 mya to present, development of mordern mammals

Answer 19

cenozoic era

Question 20

two periods in cenozoic ersa

Answer 20

tertiary and quarternary

Question 21

reptiles were formed

Answer 21

carboniferous period

Question 22

largest mass extinction

Answer 22

permian

Question 23

first birds and mammals were formed

Answer 23

jurassic

Question 24

beginning of cenozoic era, all dinosaurs and half of the other plants and animals went extinct

Answer 24

cretaceous

Question 25

humans evolved

Answer 25

quarternary period

Question 26

negative image of an organism, shells

Answer 26

molds

Question 27

when a mold is filled in

Answer 27

casts

Question 28

converted into stone

Answer 28

petrified

Question 29

preserved

Answer 29

original remains

Question 30

carbon impression in sedimentary rocks

Answer 30

carbon film

Question 31

record the movements and behaviors of the organism

Answer 31

trace

Question 32

small organsim trapped in amber, hardened plant sap

Answer 32

unaltered preservation

Question 33

hard parts are dissolved and replaced by other minerals, like calcite, silica, pyrite, or iron

Answer 33

Replacement

Question 33

Hard parts are converted to more stable minerals or small crystals turn into larger crystals

Answer 33

Recrystalization

Question 34

does not tell the exact age

Answer 34

relative dating

Question 34

two ways to measure the age of a fossil

Answer 34

relative dating and absolute dating