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 rocks lie above older rocks if the layers have not been disturbed

Question 7

isotope

Answer 7

one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behavior but with different atomic masses and physical properties. Every chemical element has one or more isotopes.

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 a different element

Question 9

half-life

Answer 9

the time needed for half of a sample of a radioactive sub stance 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. This is usually defined as about 75% of the world’s species being lost in a ‘short’ amount of geological time

Question 16

jurrassic period

Answer 16

145 million years ago, reptiles were the dominant animals

Question 17

cretaceous period

Answer 17

dinosaurs were dominant animals, 145 to 66 million years ago.

Question 18

Devonian period

Answer 18

419.2 million years ago to 358.9 million years ago,dominant animal was fish

Question 19

Quaternary period

Answer 19

mammoth was the dominant animal,2.58 million years ago.

Question 20

permian period

Answer 20

298 million years ago - 251 million years ago,the therapsids were the dominant animal.