Exam 9: Crustal Deformation

Broad upwarps in the basement rock may deform the overlying sedimentary cover strata to generate large elliptical to circular folds called ________.

As long as it is not in a region of active faulting, the structures in the bedrock are not of major concern for buildings or engineers designing construction projects like dams or nuclear power plants.

________ are the polished and striated surfaces along a fault plane that enable geologists to infer the last sense of motion on a fault.

Which types of rocks are the easiest in which to recognize and map structures and why is this so?

A thrust fault is formed by sideways movement between blocks of rock.

Which one of the following is true for anticlines but not for synclines?

A ________ fault has little or no vertical movements of the two blocks.

There were 11 earthquakes M>6.9 on the San Andreas Fault between 1812 and 1994.On average, how many years pass between earthquakes of this size, somewhere along the fault?

The ________ in California is the boundary between the North American and Pacific lithospheric plates.

________ joints form when igneous rocks cool and develop pillar-like columns.

Quartzite or marble is more likely to exhibit brittle behaviour?

During mountain building episodes, originally flat lying sedimentary and volcanic rocks are often bent into a series of ________.

A fault is observed in a road cut, but there are no obvious rocks units to correlate on either side of the fault to determine relative movement.How else might you determine or even infer whether the hanging wall has moved up or down relative to the footwall? (Hint: Think of fossils, tectonic setting, etc.)

How does elastic deformation of rocks differ from brittle or plastic deformation?

Dip-slip faults, with steep inclinations, and a footwall that rode up over its hanging wall are called reverse faults or thrust faults?

Many oil and gas deposits and artesian bedrock aquifers occur in geologic reservoirs within structural traps.

What is the axial plane of a fold?

Most high angle reverse faults ________ in regions dominated by other types of faulting.

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. -Choose the option that does not fit the pattern.

When rock is broken and pulverized as the sides of a fault grind past each other, this generates a loosely coherent, easily moved and easily eroded material called fault ________.