Fossil record

Question 1

uniformitarianism

Answer 1

A principle that states that geologic processes that occurred in the past can be explained by current geologic processes.

Question 2

catastrophism

Answer 2

A principle that states that geologic change occurs suddenly.

Question 3

paleontology

Answer 3

the scientific study of fossils.

Question 4

relative dating

Answer 4

any method of determining whether 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 rock lie above older rocks if the layers have not been disturbed.

Question 7

isotope

Answer 7

an atom that has the same number or protons or the same atomic number as other atoms of the same element do but that has a different number of neutrons.

Question 8

radioactivity 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 a sample of a radioactive substance to undergo radioactivity decay.

Question 10

fossil

Answer 10

the remains or physical evidence or an organism preserved by geological process.

Question 11

trace fossil

Answer 11

a fossilized mark that id 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

When a lot of animals go extinct at once.

Question 16

Jurassic period

Answer 16

was a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago.

Question 17

Cretaceous period

Answer 17

is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago.

Question 18

Devonian period

Answer 18

is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, 419.2 million years ago.

Question 19

Quaternary period

Answer 19

is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy.

Question 20

Permian period

Answer 20

is a geologic period and system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago.