Science Vocab Chapter 9 Flashcards
Fossils
The remains, imprints, or traces of prehistoric organisms
Permineralized remains
Fossils in which the spaces inside are filled with minerals from groundwater
Carbon Film
A silhouette of the original organism
Mold
a cavity in the rock
Cast
a copy of the original object
Index Fossils
The remains of species that existed on earth for relatively short periods of time
Principle of Superposition
The principle that in undisturbed layers of rock, the oldest rocks are on the bottome, and the rocks become progressively younger towords the top
Relative Age
something’s age in comparison to the ages of other things
Unconformities
Gaps in rock sequence
Absolute Age
The age, in years, of a rock or other object
Radioactive decay
The process of breaking down
Half-life
The time it takes for half of the atoms in an isotope to decay
Radiometric Dating
The process of measuring the ratio of a parent isotope to daughter product in a mineral, and knowing the half life
Uniformitarianism
The principle that earth processes occuring today are similliar to the ones that happened in the past
