CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Pakistan's northern mountain building is strongly related to:
A. Indian-Eurasian plate convergence
B. Atlantic ridge spreading
C. Nazca subduction
D. Pacific hotspot volcanism
Correct Answer: A
The collision of India with Eurasia drives tectonics of the Himalaya-Karakoram region.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Plate tectonics explains the global distribution of:
A. Many earthquakes, volcanoes and mountain belts
B. Only rainfall
C. Only deserts
D. Only soils
Correct Answer: A
These major geologic phenomena cluster systematically at plate interactions.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Fracture zones beyond active transform segments are:
A. Inactive scars recording past transform motion
B. Subduction trenches
C. Continental rifts
D. Volcanic arcs
Correct Answer: A
They continue across oceanic plates beyond the actively slipping transform.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Transform faults offset segments of:
A. Mid-ocean ridges
B. Only rivers
C. Only mountain summits
D. Political boundaries
Correct Answer: A
Oceanic transform faults commonly connect displaced spreading-ridge segments.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Magnetic reversals mean that Earth's magnetic field:
A. Has switched polarity repeatedly
B. Has always pointed the same way
C. Disappears every day
D. Controls plate boundaries
Correct Answer: A
Geologic records show repeated normal and reversed polarity intervals.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Paleomagnetism helps reconstruct plate motions because rocks can record:
A. Past magnetic-field orientation
B. Past rainfall exactly
C. Only fossil colour
D. River discharge
Correct Answer: A
Magnetic remanence preserves information on latitude, rotation and reversals.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Ophiolites are interpreted as fragments of:
A. Oceanic lithosphere emplaced on continents
B. River terraces
C. Continental coal seams
D. Glacial moraines
Correct Answer: A
Ophiolite sequences expose oceanic crust and upper mantle on land.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Accretionary prism forms from:
A. Sediments scraped from a subducting plate
B. Lava at a ridge axis
C. Glacial ice
D. Wind-blown sand only
Correct Answer: A
Sediments may be off-scraped and deformed at a trench.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Back-arc basins may form:
A. Behind volcanic arcs in subduction settings
B. Only in continental interiors
C. Only at passive margins
D. At river deltas
Correct Answer: A
Extension behind an arc can create back-arc spreading basins.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Aulacogen commonly refers to:
A. A failed arm of a rift system
B. An active trench
C. A volcanic cone
D. A mineral deposit
Correct Answer: A
Aulacogens are abandoned or failed rift branches.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
A triple junction is where:
A. Three plate boundaries meet
B. Three rivers meet
C. Three continents share a capital
D. Three minerals crystallize
Correct Answer: A
Plate-boundary systems can intersect at triple junctions.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Post-glacial rebound is an example of:
A. Isostatic adjustment
B. Sea-floor spreading
C. Transform faulting
D. Chemical weathering
Correct Answer: A
Removal of ice load permits previously depressed crust to rise.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Isostasy refers to:
A. Gravitational equilibrium of lithosphere floating on denser mantle
B. Earth's magnetic reversal
C. Ocean salinity
D. Weathering rate
Correct Answer: A
Crustal blocks adjust vertically according to thickness and density.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
An active continental margin is commonly associated with:
A. A plate boundary
B. No tectonic activity
C. Only coral reefs
D. A stable craton
Correct Answer: A
Active margins coincide with subduction or transform tectonics.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
A passive continental margin is generally:
A. Not a plate boundary
B. A subduction zone
C. A transform fault
D. A mid-ocean ridge
Correct Answer: A
Passive margins lie within a plate, away from active plate boundaries.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Convection in the mantle:
A. Contributes to plate-motion dynamics
B. Occurs only in the crust
C. Stops all plate motion
D. Is identical to river flow
Correct Answer: A
Mantle heat transfer and flow are part of the plate-tectonic system.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Ridge push is related to:
A. Gravitational sliding away from elevated ridges
B. Subduction trench suction only
C. Ocean tides
D. Earth's magnetic field
Correct Answer: A
Elevated young lithosphere at ridges contributes to outward gravitational force.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Slab pull refers to:
A. Gravity-driven sinking of a dense subducting plate
B. Wind stress on plates
C. River erosion
D. Rotation of Earth alone
Correct Answer: A
Negative buoyancy of a descending slab exerts an important plate-driving force.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Subduction preferentially consumes:
A. Dense oceanic lithosphere
B. Buoyant continental crust
C. Atmosphere
D. River sediment only
Correct Answer: A
Cooling oceanic lithosphere becomes dense enough to descend.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Oldest oceanic crust is generally found:
A. Farther from mid-ocean ridges
B. At ridge axes
C. Only at hotspots
D. At river mouths
Correct Answer: A
Oceanic crust ages progressively away from spreading centers.