Earth Science - Unit 8 Review

Question 1

Geologists finds identical index fossils in Arizona and Utah. What can she infer?

Accepted Answer

The rock layers are the same age

Question 2

Carbon - 14 is used to date ______ rocks because its half-life is _________.

Accepted Answer

young; 5730 years

Question 3

When did Pangea break apart?

Accepted Answer

Mesozoic Era

Question 4

Why do scientists use relative and absolute age?

Accepted Answer

Scientists may not always be able to find absolute age

Question 5

What discovery could change the geological time scale?

Accepted Answer

Discovery of new fossils

Question 6

Which statement BEST describes one rule for determining relative age of a rock layer?

Accepted Answer

A fault is always younger than the rock it cuts through

Question 7

Into which units is the geologic time scale subdivided?

Accepted Answer

eras and periods

Question 8

What do geologists MOSTLY study to develop the geologic time scale?

Accepted Answer

rock layers and index fossils

Question 9

Which is NOT a way in which rock layers can be disturbed?

Accepted Answer

superposition

Question 10

What were Earth's earliest multicellular organisms?

Accepted Answer

invertebrates

Question 11

Fossil 2 is 300 myo. Layer M is 400 myo. So Fossil 3 likely lived 350 myo.

Accepted Answer

True

Question 12

Be able to name and describe the Great Dying

Accepted Answer

Marked end of the Paleozoic Era, Preventing photosynthesis and increase of CO2 in the oxygen., Caused by volcanic eruptions blocking out sunlight, Reduced oxygen levels & high temp killed 90 % ocean and 70% of land species

Question 13

Half-life's are used to find a rocks

Accepted Answer

Absolute Age

Question 14

Which term describes the time it takes for half of a radioactive element's atoms to decay?

Accepted Answer

half-life

Question 15

A geologist finds an area of undisturbed sedimentary rock. The _____ layers is most likely the oldest.

Accepted Answer

lowest

Question 16

Reptiles came before flowering plants

Accepted Answer

True

Question 17

The geologic time scale is a record of _______ and _______.

Accepted Answer

geologic events, life forms

Question 18

Which of the following conclusions can geologists draw about a limestone rock layer based on the law of superposition?

Accepted Answer

It is younger than the sandstone layer below it

Question 19

What is NOT a reason geologists need the time scale?

Accepted Answer

It helps learn about recent events

Question 20

Potassium - 40 is used to date ______ rocks because its half-life is _________.

Accepted Answer

ancient; 1.3 billion years

Question 21

The first birds evolved during the _________.

Accepted Answer

Mesozoic Era

Question 22

What can you conclude about relative age of Fossils 1 and 2?

Accepted Answer

Fossil 2 is older

Question 23

Which of the following is NOT true about the relative ages of the rock?

Accepted Answer

Layers D, H, and J are the same age

Question 24

How do geologists use radioactive dating in developing the geologic time scale?

Accepted Answer

to determine the absolute age of rocks

Question 25

Which term describes a gap in the geologic record that occurs when sedimentary rocks cover an eroded surface?

Accepted Answer

unconformity

Question 26

Radioactive dating is a method used by geologists to determine the ______ age of rocks

Accepted Answer

Absolute

Question 27

Which time period has the LEAST amount of fossils?

Accepted Answer

Precambrian Time

Question 28

Which of the following is true about the relative ages of the rock?

Accepted Answer

Layer M is the oldest

Question 29

Which would NOT be included in picture of Devonian period?

Accepted Answer

Birds

Question 30

Which of the following is an index fossil?

Accepted Answer

Fossil 2

Question 31

When did continents move to current positions?

Accepted Answer

Cenozoic Era

Question 32

When did Pangea form?

Accepted Answer

Paleozoic Era

Question 33

What are index fossils?

Accepted Answer

widely distributed, Fossils found in sedimentary rock layers, lasting for a short time geologically

Question 34

Which event occurred in the Cenozoic era?

Accepted Answer

spread of mammals

Question 35

List rock layers form oldest to youngest

Accepted Answer

1, 2, A, 3, B, 4, C

Question 36

Why are index fossils useful?

Accepted Answer

They help scientists match and date rock layers, even if they are far apart or spread out, Rock layers with same index fossils are same age

Earth Science - Unit 8 Review

Questions 36

Earth Science - Unit 8 Review

Questions 36