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ESC1000 Chapter 11 - Geologic Time
Geologist who first attempted to explain how landscapes form and developed the concept of catastrophism.
fossils of stomach stones
Theory which proposed that Earth's various landscapes had been created by a series of fast-acting catastrophic events
Geologist who developed the principle of Uniformitarianism, considered the father of modern geology.
Principle that the present is the key to the past, and that by understanding modern processes, we can also understand ancient ones.
Dates that only show what is younger or older than what.
Dates that give an age as a number (in years).
law of superposition
Key principles in relative dating: __________; principle of original horizontality, principle of cross cutting relations, unconformities, fossil succession
Process whereby solid parts of an organism are dissolved away and replaced by mineral deposits.
Ratio of parent (P) to daughter (D) in an isotope that has experienced four half lives.
principle of original horizontality
Key principles in relative dating: law of superposition; __________, principle of cross cutting relations, principle of inclusions, unconformities, fossil succession
casts and molds
Process whereby a structure is completely dissolved away and the void left behind is filled with mineral deposits at a later time.
50,000 or less
Age of items than can be accurately aged using radiocarbon dating.
less, much less
Radiometric dating gets ______accurate as it gets older, because there is _______ parent material left to measure.
fossils of poo.
principle of cross cutting relations
Key principles in relative dating: law of superposition; principle of original horizontality, __________, principle of inclusions, unconformities, fossil succession
Percentage of the Earth's existence that is included in the Precambrian era
Key principles in relative dating: law of superposition; principle of original horizontality, principle of cross cutting relations, principle of inclusions, unconformities, __________
Key principles in relative dating: law of superposition; principle of original horizontality, principle of cross cutting relations, __________, fossil succession, principle of inclusions.
Three types of unconformaties: __________, disconformity, nonconformity
Three types of unconformaties: nonconformity, __________, angular unconformity
Three types of unconformaties: disconformity, __________, angular unconformity
bacteria, jellyfish, worms
Three types of organisms (in alphabetical order) that existed during the end of the Precambrian geological era.
Law which states that in undeformed sedimentary strata, the oldest rocks will be on the bottom and youngest will be on the top.
Percent of the Earth's existence over which the fossil records is mostly spread.
Number of years ago that the Phanerozoic geological era began.
Fossils that are used to determine absolute ages.
The geological eon in which there is an explosion of fossils.
Ratio of parent (P) to daughter (D) in an isotope that has experienced two half lives.
Age of invertebrates, fishes and amphibians
Principle that sediments are generally deposited in horizontal layers, and those that are not have gone through some sort of deformation.
the length of time taken for half of a parent isotope to decay to the daughter isotope. Is fixed for each isotope.
Age of the reptiles and dinosaurs
Less common type of fossil preservation, such as footprints, burrows and gastroliths.
cross cutting relations
Principle which states that faults and intrusions are younger than the rocks that they are found in.
Principle which states that if a mass of rock contains fragments of an adjacent rock body, the mass containing the inclusions must be younger.
Ratio of parent (P) to daughter (D) in an isotope that has experienced three half lives.
have a short geological range
Three characteristics of index fossils: 1) easy to identify, 2) widespread, 3) ___________.
Break in the rock record, created by periods of non-deposition or erosion
Unconformity where layers of strata are parallel, but they are separated by a period of non-deposition or erosion.
Unconformity where tilted or folded strata are overlain by horizontal strata.
Age of the Earth in years.
unconformity where sedimentary rocks are on top of igneous or metamorphic rocks.
the average rate of decay of an isotope.
Age of the mammals
easy to identify
Three characteristics of index fossils: 1) ___________, 2) widespread, 3) have a short geological range.
Methods of relative dating: correlating geologic columns and __________
correlating geologic columns
Methods of relative dating: __________and index fossils
Three characteristics of index fossils: 1) easy to identify, 2) ___________, 3) have a short geological range.
Ratio of parent (P) to daughter (D) in an isotope that has experienced one half life.
Matching rocks of similar type and age in different localities to build a more complete geologic column.
Use of radioactive isotopes in rocks to determine their absolute age.
Using carbon-14 to date things from the recent prehistoric past.
name of the geological period that takes up the bulk of the earth's existence.
Principle which states that fossil organisms succeed each other in a definite order, thus rocks that contain them can also be arranged in a definite order.
Types of fossilization processes: casts and molds, ________, replacement, amber, traces.
Types of fossilization processes: petrification, amber, ________, casts and molds, traces.
casts and molds
Types of fossilization processes: replacement, ________, amber, petrification, traces.
Types of fossilization processes: replacement, traces, petrification, casts and molds, ________.
Types of fossilization processes: amber, ________, petrification, replacement, casts and molds.
Process whereby tiny voids in bones and part of the organism are filled by mineral deposits
Paleozoic, Mesozoic, Cenozoic
Eras of the Phanerozoic in chronological order