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Questions and Answers
Charles Lyell tried to estimate the age of the Earth through the amount of ______ exhibited by marine mollusks in a specific time system.
Charles Lyell tried to estimate the age of the Earth through the amount of ______ exhibited by marine mollusks in a specific time system.
evolution
_______: Episodes of erosion or nondeposition between layers
_______: Episodes of erosion or nondeposition between layers
Disconformity
_______: Sediment is deposited on top of eroded volcanic or metamorphic rock (indicates very long passage of time)
_______: Sediment is deposited on top of eroded volcanic or metamorphic rock (indicates very long passage of time)
Nonconformity
Another method was to estimate the rate of deposition for ______ rocks.
Another method was to estimate the rate of deposition for ______ rocks.
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Relative ages can be determined using _______'s principle of cross-cutting relationships.
Relative ages can be determined using _______'s principle of cross-cutting relationships.
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Sir Edmund Halley proposed to estimate the age of the Earth using salt content of the ______, assuming that the oceans were once non-saline.
Sir Edmund Halley proposed to estimate the age of the Earth using salt content of the ______, assuming that the oceans were once non-saline.
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Lord Kelvin estimated the age of the Earth at 24-40 million years. He proposed that the Earth has been cooling since it formed, and he calculated the rate of cooling using principles of heat ______.
Lord Kelvin estimated the age of the Earth at 24-40 million years. He proposed that the Earth has been cooling since it formed, and he calculated the rate of cooling using principles of heat ______.
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_______ is the correlation of stratigraphic units based on fossil content.
_______ is the correlation of stratigraphic units based on fossil content.
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It wasn't until Henri Becquerel discovered radioactivity in 1896 and Madame Curie isolated ______ 2 years later that people realized that the Earth had its own source of heat.
It wasn't until Henri Becquerel discovered radioactivity in 1896 and Madame Curie isolated ______ 2 years later that people realized that the Earth had its own source of heat.
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Index fossils are known as _______ because they can be used as guides for recognition of chronostratigraphic units.
Index fossils are known as _______ because they can be used as guides for recognition of chronostratigraphic units.
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The oldest rocks found so far on Earth (based on zircon grains from Australia) have been dated at 4.1-4.2 billion ______.
The oldest rocks found so far on Earth (based on zircon grains from Australia) have been dated at 4.1-4.2 billion ______.
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Trilobites are a commonly used _______ because they are easy to recognize.
Trilobites are a commonly used _______ because they are easy to recognize.
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Earth takes ________ years to cool
Earth takes ________ years to cool
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Initial atmosphere escapes into space: ________ and ________
Initial atmosphere escapes into space: ________ and ________
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Volcanic outgassing of ________ and ________ helped build atmosphere and oceans
Volcanic outgassing of ________ and ________ helped build atmosphere and oceans
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Banded iron formation rocks appeared around ________ billion years ago
Banded iron formation rocks appeared around ________ billion years ago
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Simple, single-celled forms of life appeared around ________ billion years ago
Simple, single-celled forms of life appeared around ________ billion years ago
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Cyanobacteria began producing free oxygen through ________
Cyanobacteria began producing free oxygen through ________
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Study Notes
Estimating the Age of the Earth
- Charles Lyell attempted to estimate the age of the Earth by measuring the sedimentation rates of marine mollusks.
- Unconformities occur when there are episodes of erosion or non-deposition between layers.
- Sediment deposited on top of eroded volcanic or metamorphic rock indicates a long passage of time.
Deposition Rates and Relative Ages
- Estimating the rate of deposition for sedimentary rocks can help determine the age of the Earth.
- Relative ages can be determined using Steno's principle of cross-cutting relationships.
Early Methods of Age Estimation
- Sir Edmund Halley proposed estimating the age of the Earth based on the salt content of the oceans, assuming they were once non-saline.
- Lord Kelvin estimated the age of the Earth at 24-40 million years, proposing that the Earth has been cooling since its formation.
- Kelvin calculated the rate of cooling using principles of heat conduction.
Radioactivity and Fossil Dating
- Henri Becquerel discovered radioactivity in 1896, and Madame Curie isolated radium two years later, revealing the Earth's internal heat source.
- Biostratigraphy is the correlation of stratigraphic units based on fossil content.
- Index fossils are guide fossils, used to recognize chronostratigraphic units.
Early Earth History
- The oldest rocks found on Earth, from Australia, have been dated at 4.1-4.2 billion years old.
- Trilobites are commonly used as index fossils due to their ease of recognition.
Earth's Formation and Atmosphere
- The Earth takes millions of years to cool.
- The initial atmosphere escaped into space, including helium and hydrogen.
- Volcanic outgassing of ammonia and methane helped build the atmosphere and oceans.
Early Life and Oxygen Production
- Banded iron formation rocks appeared around 3.5 billion years ago.
- Simple, single-celled life forms emerged around 3.5 billion years ago.
- Cyanobacteria began producing free oxygen through photosynthesis.
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Description
Test your knowledge on geological dating methods and isotopes with this quiz. Explore concepts such as radiometric dating, igneous rock intrusion, and the principles of geology proposed by scientists like Hutton and Lyell.
