Deck 20: Mineral and Energy Resources

Question 1

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

A) basins
B) monoclines
C) doubly plunging anticlines
D) domes

Answer 1

A

Question 2

Which statement is not true about joints?

A) can result from ductile deformation
B) can result from tension near fold axes
C) can result from unloading of exposed batholiths
D) can result from igneous cooling

Answer 2

A

Question 3

Which one of the following would not be a characteristic of the San Andreas fault zone?

A) sag ponds
B) steep, near vertical, dip- slip, fault scarps
C) deformed, broken, and pulverized bedrock
D) laterally offset stream channels

Answer 3

B

Question 4

Crowsnest Mountain on the Lewis thrust in Alberta is an eroded thrust- outlier called a .

A) inselberg
B) klippe
C) fenster
D) soul thrust

Question 5

What are the three types of differential stress in the Earth's lithosphere?

A) compression, shear, and tension
B) hydrostatic, lithostatic, and vibratory
C) confined, unconfined, and directed
D) upwards, downwards, and sideways

Question 6

When folding occurs, rocks situated in the hinges (on the axes) of the folds are .

A) plastically deformed and extruded down the flanks of the folds
B) crushed and compressed to make them atypically dense and tight
C) elongated and pulled apart to produce tensional joints and greater fracture porosity
D) sheared out parallel to the fold limbs

Question 7

Which one of the following stress situations results in folding of flat- lying, sedimentary strata?

A) vertically directed, extensional or stretching stresses
B) vertically oriented digital stresses
C) horizontally directed, compressive stresses
D) horizontally directed, extensional stresses

Question 8

In a normal fault .

A) the footwall block, above an inclined fault plane, moves upward relative to the other block
B) the footwall block, below an inclined fault plane, moves downward relative to the other block
C) the hanging wall block, above an inclined fault plane, moves downward relative to the other block
D) the hanging wall block, below an inclined fault plane, moves downward relative to the other block

Question 9

A horst is .

A) an inflexible square head surrounded by immovable faults
B) an uplifted block bounded by two normal faults
C) a downdropped block bounded by two reverse faults
D) an uplifted block bounded by two reverse faults

Question 10

A thrust fault is best described as .

A) a near vertical, strike- slip fault
B) a vertical, normal fault
C) a low- angle, reverse fault
D) a steeply inclined, oblique- slip fault

Question 11

A transform fault is .

A) the rift- bounding faults parallel to the axial valley on a mid- ocean ridge
B) a dip- slip fault connecting an anticline with a syncline
C) a lithospheric scale, strike- slip fault that forms the boundary between tectonic plates in shear, such as at oceanic ridge offsets
D) a reverse fault that steepens into a thrust fault

Question 12

A syncline is .

A) a paralytic drunken fold characterized by recumbent limbs
B) a fold with only one limb
C) a fold in which older flanking strata dip toward the axis
D) a fold in which the older central strata dip away from the axis

Question 13

Joints in rocks are characterized by .

A) roughly parallel fractures separating blocks that show no appreciable displacement
B) structures formed where normal and reverse faults intersect
C) small cylindrical Cannabis fossils found in the Doobie- doo sandstone
D) closely spaced, parallel faults along which the blocks have moved in opposite directions

Question 14

When do rocks deform?

A) when they are quarried or mined, otherwise they are too strong to break under natural conditions
B) whenever they are subjected to stresses or strain rates which exceed their own strength
C) after their bonds weaken when they get really old
D) only during major earthquakes

Question 15

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

A) It only happens to rocks that can bounce .
B) It is reversible or recoverable and when the stress is removed, the rocks snap back to their original shape or position.
C) It can only occur once and never happens in cycles.
D) It only occurs are very fast or high strain rates.

Question 16

A is a prominent angular ridge formed by the differential erosion of tilted, alternating hard and soft strata.

A) scarp face
B) wadi
C) hogback
D) mesa

Question 17

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

A) anticlines
B) doubly plunging synclines
C) domes
D) monoclines

Question 18

What is the cause of most earthquakes?

A) sudden movements from elastic strain release and rupture along pre- existing faults on or near to plate boundaries
B) folding deep under active mountain belts
C) nuclear weapons tests in secret underground locations
D) volcanic eruptions

Question 19

Which one of the following statements regarding rock deformation and strength is correct?

A) Rupture and plastic deformation occur when stresses and strain rates exceed the elastic limit of a material.
B) Elastic deformation is accomplished through internal flow of material.
C) Rocks undergo plastic deformation less readily as temperatures and pressures increase.
D) When rocks are subjected to stress for long time spans, very small, plastic deformations accumulate to produce large, permanent, elastic deformations.

Question 20

When do rocks succumb to ductile deformation?

A) on the rims of meteorite impact craters
B) in fault zones with intermittent high strain rates
C) at great depth under active mountain belts with high confining pressure and low strain rates or prolonged strain
D) at shallow depth, at low confining pressure, and low temperature

Question 21

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

A) San Andreas strike- slip fault
B) Queen Charlotte- Fairweather right- lateral strike- slip fault
C) Moine thrust fault
D) Garlock left- lateral strike- slip fault

Question 22

Which one of the following is consistent with deformation by folding?

A) The crust is thinned.
B) The crust is stretched and elongated.
C) Horizontal distance perpendicular to fold axes is lengthened.
D) Horizontal distance is shortened perpendicular to fold axes.

Question 23

A _ _ is a planar fracture in rock along which there has been no displacement .

A) shear zone
B) joint
C) transformed crack
D) monocline

Question 24

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

A) folded anticlines and synclines
B) heaves and sags
C) box pleats
D) horsts and grabens

Question 25

Normal and reverse faults are characterized mainly by .

A) horizontal slip
B) dip slip
C) camisole slip
D) strike slip

Question 26

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

A) occur where tectonic stresses frequently switch back an forth
B) occur in local zones of crustal extension
C) exist at the very largest scales and delineate the edges of most major mountain belts
D) are small and accommodate local displacements of a few metres

Question 27

A deeply eroded, structural basin would exhibit .

A) older strata at the edges of a basin dip away from a central, horizontal, fold axis
B) outcrops of the oldest strata in the centre of the basin
C) inward dipping strata oriented in roughly circular, outcrop patterns
D) strata dipping outward away from the centre of the basin

Question 28

The Michigan geologic map shows older Precambrian crystalline metamorphic rocks, surrounding Paleozoic marine strata (in roughly circular patterns), surrounding a central core area of Carboniferous rocks. What is this structure?

A) a klippe
B) a basin
C) a dome
D) a recumbent horst

Question 29

Belts of in layered sedimentary rocks are evidence for horizontal compression and shortening.

A) tight folds
B) strike- slip faults
C) normal faults
D) horsts and grabens

Question 30

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?

A) 165 years
B) 16.5 years
C) 1.65 years
D) 1650 years

Question 31

A graben is characterized by .

A) a hanging wall block that has moved down between two normal faults
B) a footwall block that has moved down between two reverse faults
C) a hanging wall block that has moved up between two reverse faults
D) a footwall block that has moved up between two normal faults

Question 32

are planar extensional structures which thin the crust in response to horizontally directed, tensional stresses.

A) Thrust faults
B) Normal faults
C) Anticlines
D) Reverse faults

Question 33

Which is not evidence of former structural deformation or major tectonic forces that affected rocks of continental interiors?

A) extensive, flat lying younger beds disconformably overlying older strata
B) massively folded metamorphic rock units with structures that resemble putty
C) faults which juxtapose vastly different rock types like deep lower crustal granites and fluvial deposits containing coal beds
D) extinct marine fossils found hundreds of metres above sea level in tilted strata in the mountains

Question 34

Brittle deformation would be favoured over plastic deformation in which of the following conditions?

A) warmer temperatures and high confining pressures
B) shallow depths
C) high confining pressures
D) cooler temperatures and low confining pressures

Question 35

How wide is the San Andreas Fault Zone at its northern and southern ends?

A) 10 km
B) 5 km
C) >100 km
D) <1 km

Question 36

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 .

A) slickensides
B) gouge
C) grot
D) breccia

Question 37

In thrust faulting, .

A) the crust is shortened and thickened
B) horizontal, tensional stresses drive the deformation
C) grabens develop on the footwall block
D) the hanging wall block slips downward along the thrust fault

Question 38

A reverse fault is one in which .

A) the block above the fault plane has moved backwards with respect to the other block
B) one block has moved downward and the other moved horizontally along a vertical fault
C) the hanging wall block has moved up relative to the footwall block along an inclined fault
D) both blocks have moved horizontally in opposite directions along an inclined fault

Question 39

Name two landforms or distinctive landscape features that mark the trace of the San Andreas Fault.

A) long straight escarpments, narrow ridges, and sag ponds
B) chevron folds with a northwesterly plunge on the eastern side of the fault
C) hot springs and active geyser fields in central California
D) artichoke fields that have been stretched to 10 times their initial width perpendicular to the fault

Question 40

Since the San Andreas fault started moving about 29 million years ago it has moved a total distance of 560 kilometres. How many centimetres does it move per year on average?

A) 5.18 cm/yr
B) 0.518 cm/yr
C) 0.193 cm/yr
D) 1.93 cm/yr

Question 41

The outer flanks of the Colorado Plateau are marked by a series of displaying a narrow zone of steeply inclined beds that flatten out to form elevated upland areas.

A) overturned anticlines
B) imbricate thrust faults
C) recumbent synclines
D) monoclines

Question 42

What kind of faults occur where the crust is being compressed?

A) chronic
B) normal
C) reverse and thrust
D) strike slip

Question 43

are the products of horizontally directed, tensional stresses.

A) Reverse faults
B) Thrust faults
C) Crustal thickening
D) Normal faults

Question 44

Name the three basic types of geologic structures associated with crustal deformation?

Question 45

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

A) oblique- slip
B) dip- slip
C) strike- slip
D) stick- shift

Question 46

In a fault, the hanging wall block moves up over the footwall block.

A) normal
B) strike slip
C) detachment
D) reverse or thrust

Question 47

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

A) Some may be asymmetric and some may have plunging axes.
B) After erosion, the younger strata are exposed along the axial region of the fold.
C) The deeper strata are buckled upward along the fold axis.
D) The limbs dip or are inclined towards the fold axis.

Question 48

What kind of stress creates most fold belts?

A) shear
B) compressional
C) decompressional
D) tensile

Question 49

In detail, the elegant fold and flow patterns developed in deformed rock are achieved by .

A) a single application of a complex set of stresses
B) an ongoing combined effect of: distortion, sliding, and rotation of individual mineral grains
C) very rapid application of two or more strains
D) Earth's "Great Laundress"

Question 50

When measuring the orientation of a planar structure in rocks the dip direction is measured

A) backwards
B) at 90 degrees
C) parallel
D) sideways

Question 51

Considering the largest earthquakes to occur along the San Andreas Fault, which was the most damaging?

A) 1906 San Francisco
B) 1994 Northridge
C) 1857 Fort Tejon
D) 1952 Kern County

Question 52

Most crustal deformation occurs in active tectonic zones .

A) along plate margins
B) deep within old plate interiors
C) at the base of sedimentary basins
D) in thick piles of unconsolidated sedimentary strata

Question 53

A thrust fault has .

A) a shallow inclination less than 45° and a hanging wall that slid down relative to the footwall
B) a steep inclination more than 45° and a hanging wall that rode up over the footwall
C) slickensides parallel to its strike
D) a shallow inclination less than 45° and a hanging wall that rode up over the footwall

Question 54

When an overturned fold lies on its side it is called .

A) wasted
B) recumbent
C) lazy
D) reclining

Question 55

The Great Rift Valley of East Africa is characterized by .

A) mainly transform faulting along zones connecting the rift with the Red Sea
B) a belt of anticlinal and synclinal folding formed by Africa's collision with Madagascar
C) a valley formed from a series of grabens, nearly 6000 km long and flanked by tilted horsts, formed mainly by normal faulting as East Africa begins to split apart
D) mainly thrust faulting as Africa collides with Arabia

Question 56

Vertical displacements along dip- slip faults can produce long low breaks in the landscape or cliffs called , that can show the relative sense of motion across the fault.

A) strike hurdles
B) fault scarps
C) hanging walls
D) dipsy- doodles

Question 57

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

A) Backward
B) Columnar
C) Offset
D) Reverse

Question 58

When does permanent rock deformation occur?

A) only after it comes to be located on a plate margin
B) once its elastic limit is surpassed
C) once it is completely lithified and becomes inflexible
D) when it goes on a real bender

Question 59

During major earthquakes, instantaneous displacements of occur across pre- existing faults.

A) a few metres
B) a few millimetres
C) a few kilometres
D) a few thousand kilometres

Question 60

Which one of the following best describes the geology of the Black Hills region in South Dakota?

A) a large graben deeply eroded by Pleistocene glaciers
B) an elongate upwarped dome between the Cheyenne and Belle Fourche Rivers, flanked by hogbacks of the Dakota Sandstone and cored by older crystalline igneous and metamorphic rocks
C) an eroded syncline with Cretaceous and Tertiary younger, sedimentary strata in the axial region, and older, metamorphic rocks around the margins
D) a basin filled with folded, sedimentary rocks and thick Precambrian coal beds

Question 61

Name two examples of manmade construction or engineering works which require knowledge of, and adaption to, bedrock structures and associated zones of weakness?

Question 62

List two familiar substances that exhibit brittle behaviour and two other substances that exhibit ductile behaviour under ordinary strain rates (conditions).