Chapter 9 - Geologic Structures Flashcards
Geologic Structures
A geology student is trying to figure out if a certain strike-slip fault is a right-lateral fault or a left-lateral fault. What should he do?
DETERMINE THE DIRECTION IN WHICH THE FAR SIDE OF THE FAULT APPEARS TO HAVE MOVED
A geologist examines a series of faults in the field. In her field book, she writes “possible graben.” Which evidence would support her interpretation?
THE FAULTS IN THE AREA ARE NORMAL FAULTS
We can tell that many layers of rock on Earth have been deformed because:
THEY FORM HORIZONTAL LAYERS BUT ARE NOW FOLDED
A student is trying to figure out if a particular fracture is a joint or a fault. What question should she ask herself?
IS THERE EVIDENCE OF MOTION ALONG THE FRACTURE?
A geologist needs to measure the dip of a tilted rock layer. The dip is best defined as:
THE ANGLE THE SURFACE TILTS DOWN FROM HORIZONTAL
A geologist finds evidence that a rock has undergone thinning. Which type of stress is most likely to have caused this?
TENSIONAL STRESS
A student is writing up an interpretation of some folded rocks. Which interpretation is most accurate in terms of the language he uses?
COMPRESSIONAL STRESS CAUSED STRAIN IN THE FORM OF FOLDING
Reverse faults are caused by:
COMPRESSIVE STRESS
The strike is always measures ______ in relation to the dip.
PERPENDICULAR
Where is the most common place to find crustal extension (fault block mountains)?
DIVERGENT BOUNDARIES
Who was responsible for the origin of the terms hanging wall block and footwall block?
MINERS
Which of the following is not a type of dip-slip fault?
ADJACENT FAULT
Which of the following factors does not govern strain?
SOIL ACCUMULATION
What type of deformation is reversible?
ELASTIC DEFORMATION
What kind of boundary is known to experience shear stress?
TRANSFORM PLATE BOUNDARY
What kind of stress leads to the thinning of Earth’s crust?
TENSIONAL STRESS
Folds form primarily in which tectonic environment?
COMPRESSIONAL
A dip-slip fault is defined as a fault in which:
MOTION HAS OCCURRED GENERALLY PARALLEL TO THE HORIZONTAL ORIENTATION OF THE FAULT PLANE
Which statement accurately describes the relationship between stress and strain?
STRESS CAUSES STRAIN
