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Test 2

Which one of the following statements concerning foci and epicenters is correct?
The epicenter is at the surface directly above the focus where the earthquake initiates.
What are the two main criteria for identifying and naming igneous rocks?
texture and composition
What are the two main criteria for identifying and naming sedimentary rocks?
texture and composition
What are the two main criteria for identifying and naming metamorphic rocks?
texture and composition
The __________ is the idea or concept that ancient life forms succeeded each other in a definite, regular pattern and that the contained assemblage of fossils can determine geologic ages of strata?
principle of faunal succession
Which one of the following statements is correct?
S waves travel through solids and P waves travel through liquids.
What fundamental concept states that in a horizontal sequence of conformable sedimentary strata, each higher bed is younger than the bed below it?
law of superposition
__________ have the highest velocities.
Primary waves
Which of the following geologic observations would not bear directly on working out the sequence of geologic events in an area?
the feldspar and quartz contents of a granite
On a typical seismogram, __________ will show the highest amplitudes (largest deflections).
surface waves
Which two Paleozoic, geologic, time-scale periods used in North America are combined into the Carboniferous period in Europe and elsewhere?
Mississippian; Pennsylvanian
The __________ magnitude scale is a measure of the energy released, but does not directly measure the extent of building damage.
The radioactive isotopes uranium-238, uranium-235 eventually decay to different, stable, daughter isotopes of __________, each with a well-known half-life.
Approximately how much more energy is released in a 6.5 Richter magnitude earthquake than a magnitude 5.5?
32 times
A syncline is __________.
a fold in which the beds dip toward the axis
What are the smaller magnitude quakes that follow a major earthquake?
__________ are the products of horizontally directed, tensional stresses.
Normal faults
A __________ fault has little or no vertical movements of the two blocks.
strike slip
Jointing in rocks is characterized by __________.
roughly parallel fractures in rocks that show no displacement
in a __________ fault, the hanging wall block moves up with respect to the footwall block.
in thrust faulting, __________.
the crust is shortened and thickened