APSC 151 Midterm Questions
And Answers
Physical geology
✓✓✓✓~ Study of the Earth's composition, structure, and the processes that shape it.
Historical geology
✓✓✓✓~ A major division of geology that deals with the origin of Earth and its development
through time. Usually involves the study of fossils and their sequence in rock beds.
Engineering geology
✓✓✓✓~ The application of the geologic sciences to engineering practice
Hydrology
✓✓✓✓~ Study of surface water
Groundwater
✓✓✓✓~ Water that fills the cracks and spaces in underground soil and rock layers
Catastrophism
,✓✓✓✓~ A principle that states that geologic change occurs suddenly (by catastrophe)
Uniformitarianism
✓✓✓✓~ A principle that geologic processes that occurred in the past can be explained by
current geologic processes
Absolute age dating
✓✓✓✓~ Method that enables scientists to determine the actual age of certain rocks and
other objects
Radiometric dating
✓✓✓✓~ Dating using decay of radioactive isotopes to calculate the age of a rock or mineral
Relative dating
✓✓✓✓~ Placing rocks and events in a chronological sequence
Law of superposition
✓✓✓✓~ The geologic principle that states that in horizontal layers of sedimentary rock,
each layer is older than the layer above it and younger than the layer below it.
Principle of fossil succession
,✓✓✓✓~ Fossil organisms succeed one another in a definite and determinable order, and
any time period can be recognized by its fossil content.
Principle of original horizontality
✓✓✓✓~ The principle that states that layers of sediment are generally deposited in a
horizontal or nearly horizontal position.
Principle of cross-cutting relations
✓✓✓✓~ if one geologic feature cuts across another, the feature that has been cut is older
Unconformity
✓✓✓✓~ A break in the geologic record created when rock layers are eroded or when
sediment is not deposited for a long period of time (nondeposition)
Plate tectonics
✓✓✓✓~ A theory stating that the earth's surface is broken into plates that move.
Continental drift
✓✓✓✓~ The hypothesis that states that the continents once formed a single landmass,
broke up, and drifted to their present locations
Paleomagnetics
, ✓✓✓✓~ Uses magnetic directions recorded in rocks to determine the latitude at which the
rocks were formed (magnetic field is preserved in cooling lava)
Geomagnetic reversals
✓✓✓✓~ A change in the Earth's magnetic field resulting in a switch in polarity
Lithosphere
✓✓✓✓~ The rigid outer part of the earth, consisting of the crust and upper mantle.
Hot spot
✓✓✓✓~ A volcanically active area of Earth's surface far from a tectonic plate boundary. If
the crust moves, the rising mantle plume can form a chain of volcanoes
Converging plate boundary
✓✓✓✓~ A plate boundary where two plates move toward each other.
Subduction zone
✓✓✓✓~ The site at which an oceanic plate is sliding under a continental plate.
Diverging plate boundary
And Answers
Physical geology
✓✓✓✓~ Study of the Earth's composition, structure, and the processes that shape it.
Historical geology
✓✓✓✓~ A major division of geology that deals with the origin of Earth and its development
through time. Usually involves the study of fossils and their sequence in rock beds.
Engineering geology
✓✓✓✓~ The application of the geologic sciences to engineering practice
Hydrology
✓✓✓✓~ Study of surface water
Groundwater
✓✓✓✓~ Water that fills the cracks and spaces in underground soil and rock layers
Catastrophism
,✓✓✓✓~ A principle that states that geologic change occurs suddenly (by catastrophe)
Uniformitarianism
✓✓✓✓~ A principle that geologic processes that occurred in the past can be explained by
current geologic processes
Absolute age dating
✓✓✓✓~ Method that enables scientists to determine the actual age of certain rocks and
other objects
Radiometric dating
✓✓✓✓~ Dating using decay of radioactive isotopes to calculate the age of a rock or mineral
Relative dating
✓✓✓✓~ Placing rocks and events in a chronological sequence
Law of superposition
✓✓✓✓~ The geologic principle that states that in horizontal layers of sedimentary rock,
each layer is older than the layer above it and younger than the layer below it.
Principle of fossil succession
,✓✓✓✓~ Fossil organisms succeed one another in a definite and determinable order, and
any time period can be recognized by its fossil content.
Principle of original horizontality
✓✓✓✓~ The principle that states that layers of sediment are generally deposited in a
horizontal or nearly horizontal position.
Principle of cross-cutting relations
✓✓✓✓~ if one geologic feature cuts across another, the feature that has been cut is older
Unconformity
✓✓✓✓~ A break in the geologic record created when rock layers are eroded or when
sediment is not deposited for a long period of time (nondeposition)
Plate tectonics
✓✓✓✓~ A theory stating that the earth's surface is broken into plates that move.
Continental drift
✓✓✓✓~ The hypothesis that states that the continents once formed a single landmass,
broke up, and drifted to their present locations
Paleomagnetics
, ✓✓✓✓~ Uses magnetic directions recorded in rocks to determine the latitude at which the
rocks were formed (magnetic field is preserved in cooling lava)
Geomagnetic reversals
✓✓✓✓~ A change in the Earth's magnetic field resulting in a switch in polarity
Lithosphere
✓✓✓✓~ The rigid outer part of the earth, consisting of the crust and upper mantle.
Hot spot
✓✓✓✓~ A volcanically active area of Earth's surface far from a tectonic plate boundary. If
the crust moves, the rising mantle plume can form a chain of volcanoes
Converging plate boundary
✓✓✓✓~ A plate boundary where two plates move toward each other.
Subduction zone
✓✓✓✓~ The site at which an oceanic plate is sliding under a continental plate.
Diverging plate boundary
