fossil record

Question 1

uniformitarianism

Answer 1

a principle that 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

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

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

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

Question 12

mold

Answer 12

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

Question 13

cast

Answer 13

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

Question 14

unconformity

Answer 14

surface of contact between two groups of unconformable strata

Question 15

mass extinction

Answer 15

widespread and rapid decrease in biodiversity on earth

Question 16

jurassic period

Answer 16

geologic time and system that spanned 56 million years from the end of the triassic period

Question 17

cretaceous period

Answer 17

last and longest segment of the Mesozoic period

Question 18

devonian period

Answer 18

geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian

Question 19

Quaternary period

Answer 19

divided into two epochs: the Pleistocene (2.588 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today)

Question 20

permian period

Answer 20

geologic period and 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