Earth's Story and Those Who First Listened

Question 1

uniformitarianism

Answer 1

a principle that states geologic processes that occurred in the past can be explained by the current geologic process

Question 2

catastrophism

Answer 2

a principle that states geologic change occurs suddenly

Question 3

paleontology

Answer 3

the scientific study of fossils

Question 4

relative dating

Answer 4

any method of determining an event or object is older or younger than other events or objects

Question 5

absolute dating

Answer 5

any method of measuring the age of an event or object in years

Question 6

superposition

Answer 6

a principle that states that younger rocks lie above older rocks if the layer have not been disturbed

Question 7

Isotope

Answer 7

an atom that has the same number of protons ( or the same atomic number) as the other atoms of the same element do but that has a different number of neurons ( and thus a different atomic mass)

Question 8

radioactive decay

Answer 8

the process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element

Question 9

half-life

Answer 9

the time needed for half of a sample of a radioactive substance to undergo radioactive decay

Question 10

fossil

Answer 10

the remains or physical evidence of an organism preserved by geological processes

Question 11

trace fossil

Answer 11

a fossilized mark that is formed in soft sediment by the movement of an animal.

Question 12

Mold

Answer 12

a mark or cavity made in a sedimentary surface by a shell or other body

Question 13

Cast

Answer 13

a type of fossil that forms when sediments fill in the cavity left by a decomposed organism

Question 14

unconformity

Answer 14

a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time

Question 15

mass extinction

Answer 15

A mass extinction event is when species vanish much faster than they are replaced.

Question 16

Jurassic period

Answer 16

The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period, approximately 145 Mya/the Jurassic Period truly was a time in which the reptiles ruled Earth.

Question 17

Cretaceous period

Answer 17

The Cretaceous is a geological period that lasted from about 145 to 66 million years ago. dinosaurs were the dominant land animals during the Cretaceous Period

Question 18

Devonian period

Answer 18

Cartilaginous fish such as sharks and rays were common by the late Devonians. The Devonian is a geologic period and system of the Paleozoic, spanning 60.3 million years from the end of the Silurian, 419.2 million years ago, to the beginning of the Carboniferous, 358.9 Mya. It is named after Devon, England, where rocks from this period were first studied.

Question 19

Quaternary period

Answer 19

The Quaternary Period is the third and last of the three periods of the Cenozoic Era. You and I are living in this period, which began only 2.58 million years ago. … The Quaternary Period is divided into two epochs, from youngest to oldest: the Holocene and Pleistocene. We are living in the Holocene/enormous herbivores

Question 20

Permian period

Answer 20

Two important groups of animals dominated the Permian landscape: Synapsids and Sauropsids. The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic Period 251.902 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era.