Fossil Record Flashcards
fossils
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 branch of science concerned with fossil animals and plants.
relative dating
The geologic age of a fossil organism, rock, or geologic feature or event defined relative to other organisms, rocks, or features or events rather than in terms of years.
absolute dating
to give rocks an actual date, or date range, in number of years.
superposition
When two waves occupy the same point, superposition occurs. … Constructive interference is when two waves superimpose and the resulting wave has a higher amplitude than the previous waves. Destructive interference is when two waves superimpose and cancel each other out, leading to a lower amplitude.
isotope
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
radioactive decay
The spontaneous transformation of an unstable atomic nucleus into a lighter one, in which radiation is released in the form of alpha particles, beta particles, gamma rays, and other particles. The rate of decay of radioactive substances such as carbon 14 or uranium is measured in terms of their half-life .
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 distinctive and typical style, form, or character.
cast
an object made by shaping molten metal or similar material in a mold.
unconformity
a surface of contact between two groups of unconformable strata.
mass extinction
The extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt.
