Fossil record Flashcards
uniformitarianism
the theory that changes in the earth’s crust during geological history have resulted from the action of continuous and uniform processes.
catastrophism
the theory that changes in the earth’s crust during geological history have resulted chiefly from sudden violent and unusual events.
paleontology
the scientific study of life in the geologic past, based on examination of fossilized remains
relative dating
we determine which things are older or younger based on their relationships
absolute dating
measure the physical properties of an object itself and use these measurements to calculate its age
superposition
measure the physical properties of an object itself and use these measurements to calculate its age
isotope
each of two or more forms of the same element that contain equal numbers of protons but different numbers
radioactive decay
the process in which a radioactive atom spontaneously gives off radiation in the form of energy or particles to reach a more stable state
half-life
the time taken for the radioactivity of a specified isotope to fall to half its original value.
fossil
the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
trace fossil
a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
mold
a hollow container used to give shape to molten or hot liquid material (such as wax or metal) when it cools and hardens.
cast
cause (light or shadow) to appear on a surface.
unconformity
a surface of contact between two groups of unconformable strata.
mass extinction
An extinction event is a widespread and rapid decrease in the biodiversity on Earth.
