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Changing Earth

TermDefinition
Mold Fossils A fossil formed when an animal, plant, or other organism dies and is covered by sediment.
Cast Fossils A cast fossil preserves the impression of the hard parts of an organism
Carbon Film fossil an organism outline of a fossil
Trace Fossil a fossil of a footprint, trail, burrow, or other trace of an animal
Preserved Remains remains of a prehistoric creature preserved in something like a rock,amber or ice
Catastrophism idea that conditions and organisms on Earth change in quick , violent events
Uniformitarianism states that geologic processes that occur today are similar to those that have occurred in the past
stratigraphy the branch of geology that studies the order and relative age of rock/soil layers on Earth.
law of superposition states that the youngest layers of Earth are located on the surface and as you go deeper into the Earth, the layers get older.
relative age is a way of describing how old something is not by using numbers but by using a comparison.
index fossil fossil of an organism that was alive for only a short period of time, were abundant and widespread geographically; scientists can use these to assign dates to rock layers
absolute age the numerical age in years of an object
radiometric dating process to determine absolute age of an object isotopes break down into other isotopes and particles
halflife time it takes for half the atoms of an isotope to decay
Created by: irobinson