How can we help?

You can also find more resources in our Help Center.

62 terms

ESC1000 Chapter 11 - Geologic Time

STUDY
PLAY
James Usher
Geologist who first attempted to explain how landscapes form and developed the concept of catastrophism.
gastroliths
fossils of stomach stones
catastrophism
Theory which proposed that Earth's various landscapes had been created by a series of fast-acting catastrophic events
James Hutton
Geologist who developed the principle of Uniformitarianism, considered the father of modern geology.
uniformitarianism
Principle that the present is the key to the past, and that by understanding modern processes, we can also understand ancient ones.
relative
Dates that only show what is younger or older than what.
absolute
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
replacement
Process whereby solid parts of an organism are dissolved away and replaced by mineral deposits.
1:15
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.
coprolites
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
88
Percentage of the Earth's existence that is included in the Precambrian era
fossil succession
Key principles in relative dating: law of superposition; principle of original horizontality, principle of cross cutting relations, principle of inclusions, unconformities, __________
unconformities
Key principles in relative dating: law of superposition; principle of original horizontality, principle of cross cutting relations, __________, fossil succession, principle of inclusions.
angular unconformity
Three types of unconformaties: __________, disconformity, nonconformity
disconformity
Three types of unconformaties: nonconformity, __________, angular unconformity
nonconformity
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.
superposition
Law which states that in undeformed sedimentary strata, the oldest rocks will be on the bottom and youngest will be on the top.
last 12
Percent of the Earth's existence over which the fossil records is mostly spread.
540 million
Number of years ago that the Phanerozoic geological era began.
index
Fossils that are used to determine absolute ages.
Phanerozoic
The geological eon in which there is an explosion of fossils.
1:3
Ratio of parent (P) to daughter (D) in an isotope that has experienced two half lives.
Paleozoic
Age of invertebrates, fishes and amphibians
original horizontality
Principle that sediments are generally deposited in horizontal layers, and those that are not have gone through some sort of deformation.
half life
the length of time taken for half of a parent isotope to decay to the daughter isotope. Is fixed for each isotope.
Mesozoic
Age of the reptiles and dinosaurs
trace fossils
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.
inclusions
Principle which states that if a mass of rock contains fragments of an adjacent rock body, the mass containing the inclusions must be younger.
1:7
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) ___________.
unconformity
Break in the rock record, created by periods of non-deposition or erosion
disconformity
Unconformity where layers of strata are parallel, but they are separated by a period of non-deposition or erosion.
angular unconformity
Unconformity where tilted or folded strata are overlain by horizontal strata.
4.6 billion
Age of the Earth in years.
non-conformity
unconformity where sedimentary rocks are on top of igneous or metamorphic rocks.
half life
the average rate of decay of an isotope.
Cenozoic
Age of the mammals
easy to identify
Three characteristics of index fossils: 1) ___________, 2) widespread, 3) have a short geological range.
index fossils
Methods of relative dating: correlating geologic columns and __________
correlating geologic columns
Methods of relative dating: __________and index fossils
widespread
Three characteristics of index fossils: 1) easy to identify, 2) ___________, 3) have a short geological range.
1:1
Ratio of parent (P) to daughter (D) in an isotope that has experienced one half life.
correlation
Matching rocks of similar type and age in different localities to build a more complete geologic column.
radiometric dating
Use of radioactive isotopes in rocks to determine their absolute age.
radiocarbon dating
Using carbon-14 to date things from the recent prehistoric past.
Precambrian
name of the geological period that takes up the bulk of the earth's existence.
fossil succession
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.
petrification
Types of fossilization processes: casts and molds, ________, replacement, amber, traces.
replacement
Types of fossilization processes: petrification, amber, ________, casts and molds, traces.
casts and molds
Types of fossilization processes: replacement, ________, amber, petrification, traces.
amber
Types of fossilization processes: replacement, traces, petrification, casts and molds, ________.
traces
Types of fossilization processes: amber, ________, petrification, replacement, casts and molds.
petrification
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