fossil record chapter 6 Flashcards
what is the geologic process that that shapes the earth in past and now
uniformitarianism
it states that geologic occurs suddenly
catastrophism
what is scientific study of fossils
paleontology
it is method that you use to determamining weather event or object older or younger than other events or objects.
relative dating
the any method of measuring the age of things in years
- absolute dating
states younger rock lie above older rocks if not been disturbed
superposition
atom with same number of protons,atomic number as atoms of the same element do but that has a differnt number neutron make atomic mass
isotope
the way in which radioactive isotope tends to break down into a stable isotope of the same element or another.
radioactive decay
the time needed for half of a sample of a radioactive substance to undergo radioactive decay
half-life
the physical remains of something buried and saved
fossil
the mark that is formed in soft sediment by animal moving
trace fossil
the mark made in rock by a shell or other body
mold
a type of fossil that forms when sediments fill in the cavity left by a decomposed organism
cast
a break in the geologic record created when rock layers are eroded or when sediment is not deposited for long period of time.
unconformity
the death of almost everything
mass extinction
