NDSU GEOL 106 Final Exam Questions
with Complete Solutions Graded A+
updated
The theory of uniformitarianism is the idea that: - Answer-Geologic processes and
events of the presents can help to understands Earths past
During which interval of Precambrian time did the moon form? - Answer-Hadean
Why are Archean-age sedimentary rocks rare in the geologic record? - Answer-Most
sedimentary rocks formed during the Archean have been metamorphosed
During the Archean, the composition of the atmosphere was most similar to: - Answer-
The composition of gasses emitted by volcanoes (water, carbon dioxide, sulfuric acid)
Once established during the Archean, the rate of plate movement was: - Answer-Faster
than modern plate movement
The oldest rocks in the world, located in the Jack Hills, are found on which continent? -
Answer-Australia
In what type of crust are the oldest rocks on Earth found? - Answer-Continental crust
What types of fossils are found in Archean-age sedimentary rocks? - Answer-Single-
celled organisms
Which of the following contributed free oxygen to the atmosphere during the Proterozoic
Eon? - Answer-Photosynthesis by cyanobacteria
Refer to Figure 1.5. What is the oldest rock unit in the sequence exposed at Zion
National Park? - Answer-Cutler formation
Refer to Figure 1.8. How do we know that the layers of sedimentary rocks exposed here
were tilted at angle after they were deposited? - Answer-Principle of original
horizontality
Which of the following describes a disconformity in a sequence of rocks? - Answer-A
sedimentary rock deposited above an eroded sedimentary rock with the same bedding
angle
, Refer to Figure 1-15. What type of unconformity exists between the Tonto Group and
the Grand Canyon Supergroup rocks? - Answer-Angular unconformity
Refer to Figure 1-15. How old are the Vishnu Basement Rocks exposed in the Grand
Canyon? - Answer-1680-1840 million years old
Which of the following is true for all isotopes of an element? - Answer-They have the
same number of protons in their nucleus
Which of the following defines the half-life of a radioactive isotope? - Answer-The time
needed for half the parent isotope to decay to daughter isotopes
Which of the following is a radioactive isotope of carbon? - Answer-Carbon-14
Dendrochronology (tree-ring dating) can provide numerical ages of materials as old as: -
Answer-12,000 years
What are the longest intervals of time on the geologic timescale? - Answer-Eons
What is the current Era of geologic time? - Answer-Cenozoic
The two most abundant elements in Earth's crust are: - Answer-Silicon and Oxygen
Which of the following is NOT a mafic silicate mineral? - Answer-Quartz
The oldest crust in an ocean should be found: - Answer-As far as possible from a mid-
ocean ridge
Characteristics of convergent plate boundaries include: - Answer-Earthquakes along the
subducting plate
The direction of plate movement over geologic time scales is best indicated by: -
Answer-The formation of a linear chain of volcanic islands formed by a mantle hot spot
Magnetic stripes are well preserved in ocean crust and represent: - Answer-Seafloor
spreading and changes in the direction of Earth's magnetic field
A rock made from the shells of small marine animals, including those that form coral
reefs, would be almost completely made of: - Answer-Carbonate minerals
Conglomerates are rocks composed of: - Answer-Rock fragments larger than 2 mm
What type of sedimentary rock consists entirely of silt-sized clasts? - Answer-Siltsone
Which of the following sedimentary structures indicates the direction of current? -
Answer-Crossbedding
with Complete Solutions Graded A+
updated
The theory of uniformitarianism is the idea that: - Answer-Geologic processes and
events of the presents can help to understands Earths past
During which interval of Precambrian time did the moon form? - Answer-Hadean
Why are Archean-age sedimentary rocks rare in the geologic record? - Answer-Most
sedimentary rocks formed during the Archean have been metamorphosed
During the Archean, the composition of the atmosphere was most similar to: - Answer-
The composition of gasses emitted by volcanoes (water, carbon dioxide, sulfuric acid)
Once established during the Archean, the rate of plate movement was: - Answer-Faster
than modern plate movement
The oldest rocks in the world, located in the Jack Hills, are found on which continent? -
Answer-Australia
In what type of crust are the oldest rocks on Earth found? - Answer-Continental crust
What types of fossils are found in Archean-age sedimentary rocks? - Answer-Single-
celled organisms
Which of the following contributed free oxygen to the atmosphere during the Proterozoic
Eon? - Answer-Photosynthesis by cyanobacteria
Refer to Figure 1.5. What is the oldest rock unit in the sequence exposed at Zion
National Park? - Answer-Cutler formation
Refer to Figure 1.8. How do we know that the layers of sedimentary rocks exposed here
were tilted at angle after they were deposited? - Answer-Principle of original
horizontality
Which of the following describes a disconformity in a sequence of rocks? - Answer-A
sedimentary rock deposited above an eroded sedimentary rock with the same bedding
angle
, Refer to Figure 1-15. What type of unconformity exists between the Tonto Group and
the Grand Canyon Supergroup rocks? - Answer-Angular unconformity
Refer to Figure 1-15. How old are the Vishnu Basement Rocks exposed in the Grand
Canyon? - Answer-1680-1840 million years old
Which of the following is true for all isotopes of an element? - Answer-They have the
same number of protons in their nucleus
Which of the following defines the half-life of a radioactive isotope? - Answer-The time
needed for half the parent isotope to decay to daughter isotopes
Which of the following is a radioactive isotope of carbon? - Answer-Carbon-14
Dendrochronology (tree-ring dating) can provide numerical ages of materials as old as: -
Answer-12,000 years
What are the longest intervals of time on the geologic timescale? - Answer-Eons
What is the current Era of geologic time? - Answer-Cenozoic
The two most abundant elements in Earth's crust are: - Answer-Silicon and Oxygen
Which of the following is NOT a mafic silicate mineral? - Answer-Quartz
The oldest crust in an ocean should be found: - Answer-As far as possible from a mid-
ocean ridge
Characteristics of convergent plate boundaries include: - Answer-Earthquakes along the
subducting plate
The direction of plate movement over geologic time scales is best indicated by: -
Answer-The formation of a linear chain of volcanic islands formed by a mantle hot spot
Magnetic stripes are well preserved in ocean crust and represent: - Answer-Seafloor
spreading and changes in the direction of Earth's magnetic field
A rock made from the shells of small marine animals, including those that form coral
reefs, would be almost completely made of: - Answer-Carbonate minerals
Conglomerates are rocks composed of: - Answer-Rock fragments larger than 2 mm
What type of sedimentary rock consists entirely of silt-sized clasts? - Answer-Siltsone
Which of the following sedimentary structures indicates the direction of current? -
Answer-Crossbedding
