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

study of fossils

Question 4

relative dating

Answer 4

any method of determining whether an event or object 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 n years

Question 6

superposition

Answer 6

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 proton 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 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 or an organism preserved by geological process

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

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

extinction on a mass scale

Question 16

Jurassic period

Answer 16

second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 million years ago, following the Triassic Period and preceding the Cretaceous Period. During the Jurassic Period, the supercontinent Pangaea split apart

Question 17

Cretaceous period

Answer 17

characterized by the greatest development and subsequent extinction of dinosaurs and the advent of flowering plants and modern insects

Question 18

Devonian period

Answer 18

spanning 60 million years from the end of the Silurian, 419.2 million years ago (Mya), 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 name for the time in which we live. It spans the two most recent geologic epochs, the Pleistocene and the Holocene. Fossils from the Holocene epoch are like the animals living today, whereas Pleistocene fossils are much like living animals but with some differences.

Question 20

Permian period

Answer 20

geologic period and system which spans 46.7 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic period 251.902 Mya