Geology Deformation Flashcards
List three (3) rock structures that are associated with deformation?
Differential, compressional, and tensional
“What is rock deformation? How might a rock body change during deformation?”
a rock’s reaction to stress, which can cause a rock to change its shape or position; a rock may bend or fold during deformation.
“Contrast compressional and tensional stresses.”
Tensional stresses act to pull the rock apart; compressive stresses act to force rock particles inward and closer to one another.
“Compare stress and strain.”
stress is the internal force, and strain is the physical effect of that force on the object.
“Describe elastic deformation.”
when stress is imposed on rock it deformed, when released it returns to its original shape.
“How is brittle deformation different from ductile deformation?”
Brittle deformation occurs when rock is broken apart and is no longer coherent,
ductile deformation occurs when rock is bent and cannot revert to its original shape.
“List and describe the four factors that affect rock strength.”
temperature, confining pressure, rock type, and time.
“Distinguish between anticline and synclines, domes and basins, anticlines and domes.”
In anticline, rocks arch upward. A three-dimensional anticline is a dome. In a syncline, rocks arch downward. A three-dimensional syncline is a basin.
“What is the hanging wall block? Footwall block?”
The hanging wall block is the rock surface immediately above a fault and Footwall block is the rock surface below the fault.
“Contrast the movement that occurs along normal faults and reverse faults. What type of stress is indicated by each fault?”
Normal fault is when the hanging wall block moves down relative to the footwall block. Tensional stress. Reverse fault is when the hanging wall block moves up relative to the footwall block. Compressional stress.
“What type of faults are associated with fault block mountains?”
Fault-block mountains are associated with normal faults that flatten or merge with a regional-scale, low-angle fault at depth.
“How are joints different from faults?”
In contrast to faults, joints are smaller and they can occur in almost all kinds of rock formations
“Which of the three tyoes of plate boundaries does normal faulting predominate?” Thrust Faulting? Strike-Slip faulting?”
divergent boundaries
“What are two measurements used to establish the orientation of deformed strata? Distinguish between them.”
Strike and dip. Strike is the compass direction while dip is the angle of inclination.
“What is an outcrop?”
a rock formation that is visible on the surface
