Sooooddeeeee Cat Flashcards
uniformitarianism
the principle that states that geological process that occurred in the past can be explained by processes in the present
catastrophism
a principle that states that geological changes occur suddenly
paleontology
the study of fossils
relative dating
any method of determining whether an event or object is older or younger than other events or objects
absolute dating
any method of measuring the age of and event or object in years
superposition
the principle that states that younger rocks are above older rocks
isotope
an atom that has the same number of protons as other atoms of the same element do but a different amount of protons
radioactive decay
the process in which a radioactive isotope tends to break down into a stable isotope of the same or other element
half-life
the time needed for half of a sample of a radioactive substance to undergo radioactive decay
fossil
the remains or physical evidence of an organism preserved by geological processes
trace fossil
a fossilized mark that is formed in soft sediment by the movement of an animal
mold
a mark or cavity made in a sedimentary surface shell or other body
cast
a type of fossil that forms when sediments fill in the cavity left by a decomposed organism
unconformity
a break in the geoligic recor created when rock layers are erode or when sediment is not deposited for a long period of time
mass extinction
is a widespread and rapid decrease in the amount of life on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms.
