The principle that in undisturbed rock layers, the oldest rocks are on the bottom.
What is superposition?
Page 338
Each element is made of up.
What are Atoms?
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Scientists measure the amount of parent isotope and daughter isotope in a sample to material they want to date.
What is radiometric dating?
Page 348
Scientist who studies fossils.
What is Paleontologist?
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The release of energy from unstable atoms.
What is radioactivity
page 345
A piece of older rock that becomes part of a new rock.
What is inclusion?
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The name for the three different forms of hydrogen atoms.
What is Isotopes?
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Another name for radiocarbon.
What is carbon-14, or C-14
Page 348
Rising and flooding earth's continents in the past.
What is Sea Level?
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To mean the numerical age, in years, of a rock or object.
What is absolute age
page 345
Most rock-forming materials deposited in _______ layers.
What is Horizontal
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Isotopes that are unstable.
What is radioactive isotopes?
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The half-life of carbon-14.
What is 5,730 years
Page 348
Huge sheets of ice spread over parts of North America, Europe, and Asia.
What are glaciers?
Page 333
Geologists have developed accurate historical records for many geologic formations.
What is by measuring the absolute ages of rocks
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The layers of the river might ___, but their placements do not change.
What is erode?
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True or False?
Half-lifes of radioactive isotopes are only a few microseconds.
What is false?
Page 347
Radiocarbon dating is useful only for.
What is dating organic material
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Helped scientists reconstruct what the seafloor looked like.
What are Fossils and Organisms that lived in shallow oceans?
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Since the beginning of the twentieth century.
What is scientists have been able to determine the absolute ages of Rocks
Page 345
Intrudes into the rock layers forming a dike.
What is Magma?
Page 339
As time passes, more and more unstable parent isotopes decay and form stable...
What are daughter isotopes?
Page 347
As soon as U-235 is trapped in a mineral.
What is beginning to decay to lead-207 or Pb-207.
Huge teeth able to grind the coarse grasses that grew in the cold climate.
What is Mammoth?
Page 333
Radioactivity was discovered.
What is the beginning of the twentieth century
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