Assignment 7 - Mountain Building The two different sides of a dip-slip fault are called ________. a. the highwall and the low valley b. the dingwall and the dongwall c. the boothill and the hanging valley d. the footwall and the hanging wall Belts of ________ in layered sedimentary rocks are evidence for horizontal compression and shortening. a. normal faults b. strike-slip faults c. horsts and grabens d. tight folds In a normal fault ________. a. the hanging wall block, above an inclined fault plane, moves downward 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, below an inclined fault plane, moves downward relative to the other block d. the footwall block, above an inclined fault plane, moves upward relative to the other block What kind of faults occur where the crust is being compressed? a. normal b. chronic c. reverse and thrust d. strike slip A thrust fault is best described as ________. a. a low-angle, reverse fault b. a vertical, normal fault c. a steeply inclined, oblique-slip fault d. a near vertical, strike-slip fault Normal and reverse faults are characterized mainly by ________. a. dip slip b. strike slip c. thrust slip d. horizontal slip Which one of the following stress situations results in folding of flat-lying, sedimentary strata? a. horizontally directed, compressive stresses b. vertically oriented compressive stresses c. horizontally directed, extensional stresses d. vertically directed, extensional stresses When do rocks succumb to ductile deformation? a. on the rims of meteorite impact craters b. at shallow depth, at low confining pressure, and low temperature c. at great depth under active mountain belts with high confining pressure and low strain rates or prolonged strain d. in fault zones with intermittent high strain rates A thrust fault has ________. a. (X) a shallow inclination less than 45° and a hanging wall that slid down relative to the footwall b. (x) a shallow inclination less than 45° and a hanging wall that rode up over the footwall c. slickensides parallel to its strike d. a steep inclination more than 45° and a hanging wall that rode up over the footwall What are the three types of differential stress in the Earth's lithosphere? a. compression, shear, and tension b. hydrostatic, lithostatic, and vibratory c. upwards, downwards, and sideways d. confined, unconfined, and directed When an overturned fold lies on its side it is called ________. a. reclining b. lazy c. sideways d. recumbent A horst is ________. a. a downdropped block bounded by two reverse faults b. an uplifted block bounded by two normal faults c. an inflexible square head surrounded by immovable faults d. an uplifted block bounded by two reverse faults Broad upwarps in the basement rock may deform the overlying sedimentary cover strata to generate large elliptical to circular folds called ________. a. domes b. monoclines c. anticlines d. doubly plunging synclines In a ________ fault, the hanging wall block moves up over the footwall block. a. detachment b. normal c. strike slip d. reverse or thrust A graben is characterized by ________. a. a footwall block that has moved down between two reverse faults b. a hanging wall block that has moved down between two normal faults c. a footwall block that has moved up between two normal faults d. a hanging wall block that has moved up between two reverse faults A(n) ________ fault has little or no vertical movements of the two blocks. a. oblique-slip b. strike-slip c. down-slip d. dip-slip When measuring the orientation of a planar structure in rocks the dip direction is measured ________ to the strike. a. backwards b. opposite c. parallel d. at 90 degrees Strike-slip faults are caused by ___ acting on the crust. a. compresional stress b. shear stress c. folding stress d. tensional stress ________ are the products of horizontally directed, tensional stresses. a. Normal faults b. Reverse faults c. Strike-slip faults d. Thrust faults
