Geologic Timescale

Question 1

What is the guiding principle in the study of the Earth’s history? It states that the present is the key to the past.

Answer 1

Uniformitarianism

Question 2

Fossils are deposited in the sedimentary layers of rocks. True or False

Answer 2

True

Question 3

New sedimentary rock layers are almost always flat. True or False

Answer 3

True

Question 4

Sedimentary rocks are not formed from fragments of other types of rocks. True or false

Answer 4

False

Question 5

This is used to determine whether an object or event is older or younger than other objects

Answer 5

Relative Dating

Question 6

What kind of principle of relative dating states that sedimentary rocks are originally formed in Horizontal layers.?

Answer 6

Law of original horizontality

Question 7

Horizontality occurs in an area of land that is forced to bend. True or False

Answer 7

True

Question 8

What kind of principle of relative dating states that rock layers above are younger than the ones below it?

Answer 8

Law of superposition

Question 9

What kind of principle of relative dating states that any rock or fault that cuts across other rocks is younger than those it cuts across?

Answer 9

Principles of cross-cutting relationship

Question 10

What kind of principle of relative dating states that new forms in regions of separation?

Answer 10

Idea of unconformities

Question 11

These are surfaces of erosions that separate younger rocks from older ones.

Answer 11

Unconformities

Question 12

The method of measuring the absolute age of an event or object.

Answer 12

Absolute dating

Question 13

To determine the absolute ages of rocks and fossils, what does scientists analyzes?

Answer 13

Isotopes of radioactive elements

Question 14

These are atoms of the same element that have similar number of protons but different numbers of neutrons.

Answer 14

Isotopes

Question 15

What do you call unstable isotopes in which they break down into stable isotopes or other elements?

Answer 15

Radioactive

Question 16

What do you call an unstable radioactive isotope?

Answer 16

Parent isotope

Question 17

What do you call a stable isotope produced by the radioactive decay?

Answer 17

Daughter isotope

Question 18

The more daughter material there is, the older the rock. True or False

Answer 18

True

Question 19

Time needed for half of a sample of a radioactive substance to undergo radioactive decay

Answer 19

Half-life

Question 20

A method achieved by determining the absolute age of a sample based on the ratio of parent material to daughter material.

Answer 20

Radiometric dating

Question 21

A kind of radiometric that uses potassium-40, which has a half-life of 1.25 billion years

Answer 21

potassium-argon

Question 22

A kind of radiometric that uses uranium-238, which has a half-life of 4.5 billion years

Answer 22

uranium-lead

Question 23

A kind of radiometric that uses rubidium-87, which has a half-life of 49 billion years

Answer 23

rubidium-strontium

Question 24

A kind of radiometric that is used mainly for dating things that lived within the last 50,000 years, which has a half-life of 5,730 years.

Answer 24

carbon-14

Question 25

The remnant of any ancient animal or plant that has been preserved in crystallize rocks

Answer 25

fossils

Question 26

The age of the fossil is not equal to the age of the rock from where it is found. True or False

Answer 26

False

Question 27

The system used to related stratigraphy and time to any geologic events

Answer 27

Geologic Timescale

Question 28

Who was given a title as "the Father of Stratigraphy"?

Answer 28

Nicholas Steno

Question 29

What eon did the vast bulk of the Earth's history occurred?

Answer 29

Precambrian

Question 30

What eon is considered as the "chaotic eon"?

Answer 30

Hadean

Question 31

The eon or period when Earth became warm but the atmosphere contained only methane

Answer 31

Archean

Question 32

The eon when the atmosphere began to have oxygen

Answer 32

Proterozoic

Question 33

An era where fossils of marine invertebrates were formed in sedimentary rocks

Answer 33

Paleozoic

Question 34

An era where marine life forms developed shells

Answer 34

Middle Paleozoic

Question 35

The period where animals began to breathe air as amphibians came out of the sea

Answer 35

Devonian

Question 36

An era where reptiles started to appear like dinosaurs

Answer 36

Late Paleozoic

Question 37

The era that was marked by the breakup of the major landmasses

Answer 37

Mesozoic

Question 38

The era where mountains are uplifted and new life forms appeared

Answer 38

Cenozoic