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GEO01 CO6
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GEO01 CO6
GEO01 CO6
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1
Question
What was the accepted age of the Earth prior to the 19th century based on Western culture?
Answer
6,000 years based on biblical beliefs.
2
Question
What is the Principle of Uniformitarianism?
Answer
The principle that geologic features can be explained through present day processes and that it requires vast amounts of time. It states that 'the present is the key to the past.'
3
Question
Who is known as the Father of Geology?
Answer
James Hutton.
4
Question
Define numerical age in geology.
Answer
Numerical age is the actual age given in years or other units of time.
5
Question
Define relative time in geology.
Answer
Relative time is the sequence in which events took place.
6
Question
What is a formation in geology?
Answer
A body of rock of considerable thickness with recognizable characteristics allowing it to be distinguished from adjacent rock layers.
7
Question
What is the principle of original horizontality?
Answer
The principle that beds of sediment deposited in water are initially formed as horizontal or nearly horizontal layers.
8
Question
What does the principle of superposition state?
Answer
In an undisturbed sequence of sedimentary or volcanic rocks, layers get younger from bottom to top.
9
Question
What does the principle of lateral continuity state?
Answer
Original horizontal layers extend laterally until they taper or thin at their edges.
10
Question
Explain cross-cutting relationships in geology.
Answer
A disrupted pattern is older than the cause of the disruption; intrusions and faults are younger than the rocks they cut through.
11
Question
What are baked contacts in geology?
Answer
Contacts between igneous intrusions and surrounding rocks where the surrounding rocks have experienced contact metamorphism.
12
Question
What are inclusions in geology?
Answer
Fragments embedded in host rock that are older than the host rock.
13
Question
Define unconformities in geology.
Answer
Unconformities are surface contacts that represent a gap in the geologic record.
14
Question
What is a disconformity?
Answer
A disconformity is an unconformity contact that separates beds that are parallel to one another.
15
Question
What is an angular unconformity?
Answer
An angular unconformity is an unconformity contact that separates a younger layer above from a lower layer that is tilted.
16
Question
Define nonconformity in geology.
Answer
A nonconformity is an unconformity in which an erosional surface on plutonic or metamorphic rock has been covered by younger sedimentary or volcanic rock.
17
Question
What is correlation in geology?
Answer
Correlation is the determination of the time equivalency of rock units.
18
Question
What is isotopic dating?
Answer
Isotopic dating puts absolute values, for example, millions of years, on the ages of rocks and geologic time periods.
19
Question
What is radioactive decay?
Answer
The spontaneous nuclear change of isotopes with unstable nuclei.
20
Question
Define half-life in the context of isotopic dating.
Answer
Half-life is the time it takes for a given amount of radioactive isotope to be reduced by half.
21
Question
What is radiocarbon dating?
Answer
Radiocarbon dating evaluates the ratio of carbon-12 to carbon-14 and is used to date objects up to 40,000 years old.
22
Question
What does the geologic time scale represent?
Answer
The geologic time scale is a worldwide relative time scale that subdivides geologic time based on fossil assemblages and time.
23
Question
What does the Precambrian represent in geologic time?
Answer
The Precambrian represents 87% of geologic time and is divided into three eons: Hadean, Archean, and Proterozoic.
24
Question
When was the Earth created according to James Ussher?
Answer
James Ussher proposed that the Earth was created in 4004 B.C. based on the Bible.
25
Question
What is the significance of the Great Ordovician Biodiversification Event (GOBE)?
Answer
The GOBE occurred 40 million years after the Cambrian Explosion, leading to diversification at various taxonomic levels.
26
Question
What are index fossils?
Answer
Index fossils, also known as guide fossils or indicator fossils, are used to define boundaries in the geologic time scale and for the time correlation of strata.
27
Question
What characteristics must a good index fossil have?
Answer
1. Short geologic range 2. Widespread distribution 3. Facies independence 4. Distinctive and easily recognized form 5. Preservable hard parts 6. Abundance.
28
Question
What is absolute dating in geology?
Answer
Absolute dating is a method for measuring geologic time directly in terms of a specific number of years.
29
Question
Describe the process of alpha decay.
Answer
Alpha decay involves the emission of an alpha particle consisting of two protons and two neutrons, reducing the mass number by four and the atomic number by two.
30
Question
What happens during beta decay?
Answer
In beta decay, a beta particle or electron is emitted; the mass number remains unchanged while the atomic number increases by one.