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Geological Time

QuestionAnswer
Fossil the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
Index Fossil a fossil that is useful for dating and correlating the strata in which it is found.
Permineralized remains a process of fossilization in which mineral deposits form internal casts of organisms
Molds & casts Molds and casts are three dimensional and preserve the surface contours of the organism.
Original remains Fossils are formed when minerals in groundwater replace materials in bones and tissue, creating a replica in stone of the original organism or of their tracks.
Trace fossils a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
Relative age 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
Superposition Superposition is a principle of quantum theory that describes a challenging concept about the nature and behavior of matter and forces at the sub-atomic level.
Horizontally parallel to the plane of the horizon
Absolute age the true age of a rock or fossil
Half-life the time taken for the radioactivity of a specified isotope to fall to half its original value
Isotopes 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
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
Geologic time a system of chronological measurement that relates stratigraphy to time, and is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships between events that have occurred throughout Earth's history.
Eon an indefinite and very long period of time, often a period exaggerated for humorous or rhetorical effect.
Era a long and distinct period of history with a particular feature or characteristic.
Period a length or portion of time.
Epoch a period of time in history or a person's life, typically one marked by notable events or particular characteristics.
Pangaea a hypothetical supercontinent that included all current land masses, believed to have been in existence before the continents broke apart during the Triassic and Jurassic Periods.
Trilobite an extinct marine arthropod that occurred abundantly during the Paleozoic era
Precambrian of, relating to, or denoting the earliest eon, preceding the Cambrian period and the Phanerozoic eon.
Mesozoic Era The Mesozoic Era includes the Triassic, Jurassic, and Cretaceous Periods and is characterized by the development of flying reptiles, birds, and flowering plants and by the appearance and extinction of dinosaurs
Cenozoic Era The most recent era of geologic time, from about 65 million years ago to the present
Created by: Ian Schrogie