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NSSCAS Geography 8233 practice questions

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Question 1Physical Geography: Atmosphere, Weather and Climate

Which gas in the atmosphere is the principal absorber of incoming ultraviolet radiation in the stratosphere?

  1. Carbon dioxide
  2. Ozone Correct answer.
  3. Water vapour
  4. Argon

Explanation

Ozone concentrated in the stratosphere absorbs most incoming ultraviolet radiation, protecting the surface and warming that layer. Carbon dioxide and water vapour absorb mainly infrared radiation, and argon is chemically inert with negligible absorption.

Question 2Physical Geography: Atmosphere, Weather and Climate

Atmospheric pressure decreases with height above sea level mainly because

  1. Density and the mass of overlying air both decrease Correct answer.
  2. The proportion of oxygen in the air rises
  3. Temperature falls steadily through the whole atmosphere
  4. Gravity becomes weaker with increasing altitude

Explanation

Pressure is the weight of overlying air, so it falls as the mass of air above and its density decrease with altitude. Gravity weakens only slightly over the troposphere, and oxygen proportion actually falls with height.

Question 3Physical Geography: Atmosphere, Weather and Climate

Which process transfers heat to the lower atmosphere primarily through the release of latent heat?

  1. Absorption of shortwave radiation by nitrogen
  2. Advection of cold air masses
  3. Conduction from the warm ground
  4. Condensation of rising water vapour Correct answer.

Explanation

When water vapour condenses in rising air, stored latent heat is released and warms the surrounding atmosphere. Conduction warms air only in a shallow layer, and nitrogen absorbs very little incoming radiation.

Question 4Physical Geography: Atmosphere, Weather and Climate

A wind blows when air moves from a region of high pressure to a region of low pressure because of

  1. The pressure gradient force Correct answer.
  2. Latent heat release
  3. The Coriolis force
  4. Frictional drag

Explanation

The pressure gradient force drives air from higher toward lower pressure and is the primary cause of wind. The Coriolis force only deflects moving air, and friction only slows it near the surface.

Question 5Physical Geography: Atmosphere, Weather and Climate

Which instrument is used to measure relative humidity directly?

  1. Hygrometer Correct answer.
  2. Barometer
  3. Campbell-Stokes recorder
  4. Anemometer

Explanation

A hygrometer, such as a wet-and-dry bulb psychrometer, measures humidity by comparing wet and dry bulb temperatures. A barometer measures pressure, an anemometer measures wind speed, and a Campbell-Stokes recorder measures sunshine duration.

Question 6Physical Geography: Atmosphere, Weather and Climate

Which cloud type is characteristic of stable air with weak vertical motion and produces steady, prolonged rain?

  1. Cirrocumulus
  2. Altocumulus castellanus
  3. Cumulonimbus
  4. Nimbostratus Correct answer.

Explanation

Nimbostratus forms in stable, layered air and produces continuous, moderate to heavy precipitation. Cumulonimbus and castellanus indicate instability with strong vertical development, while cirrocumulus is a high, thin cloud with no rain.

Question 7Physical Geography: Atmosphere, Weather and Climate

The intertropical convergence zone (ITCZ) is best described as a belt where

  1. Mid-latitude depressions form along the polar front
  2. Subtropical high pressure cells cause descending air
  3. Trade winds from each hemisphere converge and air rises Correct answer.
  4. Polar easterlies meet the westerlies and air sinks

Explanation

The ITCZ marks the convergence of the northeast and southeast trade winds near the thermal equator, where warm moist air rises. Sinking air occurs in the subtropical highs, and the polar front lies at higher latitudes.

Question 8Physical Geography: Atmosphere, Weather and Climate

Which term describes the boundary between two air masses of contrasting temperature and humidity?

  1. Isobar
  2. Front Correct answer.
  3. Isotherm
  4. Jet stream

Explanation

A front is the transition zone where two air masses of different density meet, often producing cloud and precipitation. Isotherms and isobars are map lines of equal temperature and pressure, and a jet stream is a fast upper-air current.

Question 9Physical Geography: Atmosphere, Weather and Climate

In the Northern Hemisphere, the Coriolis force deflects moving air to the

  1. Direction of the pressure gradient
  2. Right of its direction of motion Correct answer.
  3. Centre of the nearest low pressure
  4. Left of its direction of motion

Explanation

Because of the Earth's rotation, moving air in the Northern Hemisphere is deflected to the right of its path, producing anticlockwise flow around lows. Southern Hemisphere deflection is to the left.

Question 10Physical Geography: Atmosphere, Weather and Climate

A parcel of air at 20 degrees Celsius with a dew point of 12 degrees Celsius is forced to rise. Using a dry adiabatic lapse rate of 10 degrees Celsius per kilometre, at approximately what height will condensation begin?

  1. 200 m
  2. 2000 m
  3. 1200 m
  4. 800 m Correct answer.

Explanation

The air must cool from 20 to 12 degrees Celsius, a drop of 8 degrees, before reaching its dew point. At the dry adiabatic lapse rate of 10 degrees Celsius per kilometre, this requires about 0.8 km, or 800 m.

Question 11Physical Geography: Atmosphere, Weather and Climate

A station reports a wind blowing from the northwest. Toward which compass direction is the air moving?

  1. Northeast
  2. Southwest
  3. Southeast Correct answer.
  4. Northwest

Explanation

Wind direction is named by the direction from which the wind blows, so a northwesterly wind travels toward the southeast. The other options confuse the source direction with the destination or rotate it incorrectly.

Question 12Physical Geography: Atmosphere, Weather and Climate

A cold front passing a station is typically associated with

  1. Clear skies and rising temperature
  2. A long period of gentle stratiform rain
  3. Persistent fog with little wind
  4. A short burst of heavy showery rain and a temperature fall Correct answer.

Explanation

At a cold front, steeply rising warm air behind the advancing cold air produces narrow bands of intense cumuliform rain, followed by cooler air. Prolonged gentle rain is typical of a warm front.

Question 13Physical Geography: Atmosphere, Weather and Climate

Why does an anticyclone generally bring settled, dry weather in summer?

  1. Rapid uplift produces tall cumulonimbus clouds
  2. Surface winds converge strongly and rise
  3. Descending air suppresses cloud formation Correct answer.
  4. Frontal systems are drawn into its centre

Explanation

In an anticyclone, air subsides and warms adiabatically, reducing relative humidity and inhibiting cloud development. Convergence and uplift occur in cyclones, not anticyclones.

Question 14Physical Geography: Atmosphere, Weather and Climate

The rain shadow effect on a mountain range occurs because

  1. Air gains moisture as it descends the leeward slope
  2. Cold air sinks on the windward side and prevents rain
  3. Both slopes receive equal orographic rainfall
  4. Air cools and loses moisture on the windward slope, then warms and dries on the leeward slope Correct answer.

Explanation

Air forced over the windward slope cools adiabatically, condenses and drops precipitation; descending the leeward slope it warms and its relative humidity falls. This produces a dry leeward zone called a rain shadow.

Question 15Physical Geography: Atmosphere, Weather and Climate

Which condition is required for the formation of radiation fog on a clear autumn night?

  1. High daytime temperatures and strong convection
  2. Strong winds and unstable air
  3. Rapid nocturnal cooling of moist air near the surface Correct answer.
  4. A passing cold front with heavy showers

Explanation

Radiation fog forms when the ground cools rapidly by longwave emission on clear nights, chilling the air above to its dew point. Strong winds mix the air and prevent the stable, shallow cooling needed.

Question 16Physical Geography: Atmosphere, Weather and Climate

The greenhouse effect warms the lower atmosphere because greenhouse gases

  1. Block the passage of shortwave radiation from the Sun
  2. Reflect incoming solar radiation back to space
  3. Absorb outgoing longwave radiation and re-emit it in all directions Correct answer.
  4. Increase the proportion of oxygen in the atmosphere

Explanation

Greenhouse gases absorb infrared radiation emitted by the Earth's surface and re-emit part of it downward, warming the lower atmosphere. They are largely transparent to incoming shortwave radiation.

Question 17Physical Geography: Atmosphere, Weather and Climate

A weather map shows isobars closely packed together. This indicates

  1. The absence of any pressure difference
  2. Light and variable winds
  3. A steep pressure gradient and strong winds Correct answer.
  4. An anticyclone with calm conditions

Explanation

Closely spaced isobars mean pressure changes rapidly over a short distance, producing a strong pressure gradient force and hence strong winds. Widely spaced isobars indicate gentle gradients and light winds.

Question 18Physical Geography: Atmosphere, Weather and Climate

Which sequence correctly orders the layers of the atmosphere from the surface upward?

  1. Troposphere, stratosphere, mesosphere, thermosphere Correct answer.
  2. Troposphere, mesosphere, stratosphere, thermosphere
  3. Stratosphere, troposphere, thermosphere, mesosphere
  4. Mesosphere, troposphere, stratosphere, thermosphere

Explanation

The atmosphere is layered, from the surface upward, as troposphere, stratosphere, mesosphere and thermosphere. Each layer is separated by a pause where the temperature trend reverses.

Question 19Physical Geography: Atmosphere, Weather and Climate

The dominant cause of the seasonal variation in solar radiation received at a mid-latitude location is

  1. Variations in atmospheric carbon dioxide
  2. The rotation of the Earth on its axis
  3. Changes in the Sun's energy output
  4. The tilt of the Earth's axis relative to its orbital plane Correct answer.

Explanation

The 23.5 degree axial tilt changes the angle of incoming solar radiation and day length through the year, producing seasons. Solar output and carbon dioxide vary too little, and rotation causes day and night rather than seasons.

Question 20Physical Geography: Atmosphere, Weather and Climate

A parcel of unsaturated air at 15 degrees Celsius rises 500 m at the dry adiabatic lapse rate (10 degrees Celsius per kilometre). If the environmental lapse rate is 6 degrees Celsius per kilometre, the air is

  1. Neutral, because the two lapse rates are equal
  2. Conditionally unstable, because the parcel reaches saturation
  3. Unstable, because the parcel cools slower than the environment
  4. Stable, because the parcel cools faster than the environment Correct answer.

Explanation

The rising parcel cools at 10 degrees Celsius per kilometre while the surrounding air cools at only 6 degrees Celsius per kilometre. The parcel becomes colder and denser than its surroundings, so it resists further uplift and the air is stable.

Question 21Physical Geography: Atmosphere, Weather and Climate

Which combination of factors most strongly favours the development of a tropical revolving storm (hurricane)?

  1. Cold ocean currents and strong upper-level winds
  2. Sea surface temperatures above 26 degrees Celsius, high humidity and weak vertical wind shear Correct answer.
  3. Descending air and high surface pressure
  4. High latitude and a strong polar front

Explanation

Tropical storms require warm ocean water above about 26 degrees Celsius to supply latent heat, abundant moisture, and low vertical wind shear so the vertical column stays organised. Cold water and strong shear disrupt development.

Question 22Physical Geography: Atmosphere, Weather and Climate

A station at 2000 m records a temperature of 5 degrees Celsius. Assuming a normal environmental lapse rate of 6.5 degrees Celsius per kilometre, what is the approximate sea-level temperature?

  1. 18 degrees Celsius Correct answer.
  2. 8 degrees Celsius
  3. 23 degrees Celsius
  4. 13 degrees Celsius

Explanation

Descending 2 km at 6.5 degrees Celsius per kilometre warms the air by about 13 degrees. Adding this to the 5 degrees Celsius at 2000 m gives approximately 18 degrees Celsius at sea level.

Question 23Physical Geography: Atmosphere, Weather and Climate

During the day, a coastal sea breeze develops because

  1. The sea heats faster than the land, creating onshore flow
  2. The land heats faster than the sea, creating lower pressure over land and onshore flow Correct answer.
  3. Cold air sinks over the land and flows out to sea
  4. Both land and sea heat equally, producing no pressure difference

Explanation

Land has a lower specific heat capacity, so it warms more quickly than the sea by day. Air over the land rises, lowering surface pressure and drawing cooler air inland from the sea as a sea breeze.

Question 24Physical Geography: Atmosphere, Weather and Climate

A city centre is consistently warmer at night than the surrounding countryside mainly because

  1. Cities receive more direct solar radiation than the countryside
  2. Rural areas have higher humidity and absorb more heat
  3. Urban surfaces and buildings store and release heat, and anthropogenic heat is added Correct answer.
  4. Urban areas have stronger winds that warm the air

Explanation

Concrete and tarmac absorb and re-radiate heat, buildings reduce longwave loss, and human activities release heat, producing the urban heat island. Rural humidity and reduced urban wind do not explain the warmth.

Question 25Physical Geography: Atmosphere, Weather and Climate

Which pressure system is associated with subsiding air, divergence at the surface and generally clear skies?

  1. A tropical depression
  2. A frontal trough
  3. A low-pressure system
  4. An anticyclone Correct answer.

Explanation

An anticyclone is a region of high pressure where air descends, diverges at the surface and suppresses cloud formation, giving settled weather. Descending air warms adiabatically, reducing relative humidity and limiting condensation.

Question 26Physical Geography: Atmosphere, Weather and Climate

Which type of rainfall is produced when moist air is forced to rise over a mountain barrier?

  1. Frontal rainfall
  2. Convectional rainfall
  3. Orographic rainfall Correct answer.
  4. Cyclonic rainfall

Explanation

Orographic rainfall occurs when relief forces moist air to ascend, cooling it adiabatically until condensation and precipitation follow. The leeward side then experiences a rain shadow.

Question 27Physical Geography: Atmosphere, Weather and Climate

A parcel of air at sea level has a temperature of 25 degrees Celsius and a dew point of 15 degrees Celsius. Using a dry adiabatic lapse rate of 10 degrees Celsius per kilometre, at approximately what height will condensation begin if the air is forced to rise?

  1. 500 metres
  2. 2500 metres
  3. 1500 metres
  4. 1000 metres Correct answer.

Explanation

The air must cool by 10 degrees Celsius to reach its dew point of 15 degrees Celsius. At 10 degrees Celsius per kilometre, that requires about one kilometre of ascent, so condensation begins near 1000 metres.

Question 28Physical Geography: Atmosphere, Weather and Climate

Which statement best explains why relative humidity typically rises during the night in a humid lowland area?

  1. Air temperature falls toward the dew point while water vapour content stays nearly constant Correct answer.
  2. The absolute amount of water vapour in the air increases rapidly after sunset
  3. Evaporation from the ground increases as the ground cools
  4. Surface pressure falls, allowing the air to hold more water vapour

Explanation

Relative humidity is the ratio of actual vapour content to the saturation capacity at that temperature. Overnight cooling lowers the saturation capacity while the vapour content changes little, so relative humidity rises toward 100 per cent.

Question 29Physical Geography: Atmosphere, Weather and Climate

A weather station reports a temperature of 18 degrees Celsius with a dew point of 17 degrees Celsius and a slow overnight fall in temperature under clear skies and light winds. Which outcome is most likely by dawn?

  1. Radiation fog forming in the lowest layers Correct answer.
  2. Deep convective cumulonimbus developing
  3. The dew point falling well below the air temperature
  4. A rapid rise in relative humidity accompanied by strong gusty winds

Explanation

With the air temperature already close to the dew point, slight nocturnal cooling under clear skies and light winds will bring the air to saturation near the ground. This produces radiation fog, which typically forms in calm, clear anticyclonic conditions.

Question 30Physical Geography: Atmosphere, Weather and Climate

A tropical revolving storm intensifies while its central pressure falls and upper-level outflow strengthens. Which combination best explains this intensification?

  1. Release of latent heat from condensation over warm water, with efficient upper-level divergence Correct answer.
  2. Strong vertical wind shear together with cool sea-surface temperatures
  3. Subsidence in the eye together with increased surface friction over land
  4. Advection of cold, dry continental air into the storm core

Explanation

Latent heat released by condensation in towering cumulonimbus warms the core and lowers central pressure, while efficient upper-level outflow removes rising air and sustains the circulation. Warm ocean surfaces above about 27 degrees Celsius supply the necessary moisture and energy.

Question 31Physical Geography: Landforms, Tectonics and Drainage

At a divergent plate boundary where oceanic lithosphere is pulling apart, which landform is produced directly at the boundary itself?

  1. A deep ocean trench
  2. A fold mountain chain
  3. A mid-ocean ridge with a central rift valley Correct answer.
  4. A volcanic island arc

Explanation

Where two oceanic plates move apart, magma rises to fill the gap and solidifies, building a broad ridge. Extension at the crest produces the central rift valley, so the ridge and rift form together at the boundary.

Question 32Physical Geography: Landforms, Tectonics and Drainage

Which type of plate boundary is associated with shallow-focus earthquakes but neither volcanic activity nor significant mountain building?

  1. Continental-continental convergent boundary
  2. Oceanic-continental convergent boundary
  3. Oceanic-oceanic divergent boundary
  4. Transform boundary Correct answer.

Explanation

At a transform boundary plates slide horizontally past one another, so crust is neither created nor destroyed. Friction and stick-slip movement generate shallow earthquakes, but no magma is produced and no crust is shortened.

Question 33Physical Geography: Landforms, Tectonics and Drainage

A river flows from a highland source to the sea. Which change in its long profile is normally expected downstream?

  1. The gradient decreases and the channel becomes wider and deeper Correct answer.
  2. The gradient decreases while sediment calibre increases
  3. The gradient stays constant while discharge falls
  4. The gradient increases and the channel becomes narrower

Explanation

Downstream, discharge rises as tributaries join, so the channel enlarges to carry the water. At the same time the long profile flattens as the river approaches base level, giving a gentler gradient in the lower course.

Question 34Physical Geography: Landforms, Tectonics and Drainage

Which process is the main way a river erodes a bedrock channel by grinding rock fragments against the bed and banks?

  1. Attrition
  2. Solution
  3. Hydraulic action
  4. Abrasion Correct answer.

Explanation

Abrasion is the mechanical wear caused by sediment carried by the river scraping and scouring the channel. The load acts like sandpaper on the bedrock, smoothing and deepening the channel over time.

Question 35Physical Geography: Landforms, Tectonics and Drainage

Which feature is formed by the deposition of material where a river enters a standing body of water and its velocity suddenly falls?

  1. A delta Correct answer.
  2. A gorge
  3. A waterfall
  4. A meander

Explanation

When a river meets a lake or the sea, its velocity drops abruptly and its competence falls. The load is deposited at the mouth, and repeated deposition builds a delta out into the water body.

Question 36Physical Geography: Landforms, Tectonics and Drainage

Which rock type forms from the cooling and solidification of magma or lava?

  1. Bioclastic limestone
  2. Igneous rock Correct answer.
  3. Sedimentary rock
  4. Metamorphic rock

Explanation

Igneous rocks crystallise from molten material, either below the surface as intrusive bodies or at the surface as lava flows. Cooling rate controls crystal size, giving coarse or fine textures.

Question 37Physical Geography: Landforms, Tectonics and Drainage

Which type of weathering dominates in a hot, humid tropical climate?

  1. Chemical weathering, especially hydrolysis Correct answer.
  2. Frost shattering
  3. Pressure release from unloading
  4. Salt crystallisation

Explanation

High temperatures and abundant moisture speed up chemical reactions, and hydrolysis of silicate minerals is especially rapid. Warmth acts as a catalyst and water supplies the reactants, so chemical weathering outpaces mechanical processes.

Question 38Physical Geography: Landforms, Tectonics and Drainage

Which glacial process produces a U-shaped valley?

  1. Deposition of till at the ice margin
  2. Abrasion and plucking by a valley glacier Correct answer.
  3. Vertical incision by a meltwater stream
  4. Chemical solution of limestone by glacial meltwater

Explanation

A glacier erodes its bed by abrasion, where rock embedded in the ice grinds the floor and sides, and by plucking of loosened blocks. These processes widen and deepen the valley, giving the characteristic U-shaped cross-profile.

Question 39Physical Geography: Landforms, Tectonics and Drainage

A geologist finds a bed of rounded pebbles cemented together with sand. Which interpretation of this rock is most reasonable?

  1. It is a chemical precipitate formed by evaporation of seawater
  2. It is an intrusive igneous rock that cooled slowly at depth
  3. It is a metamorphic rock formed by contact metamorphism
  4. It is a clastic sedimentary rock deposited in a high-energy environment such as a river or beach Correct answer.

Explanation

Rounded clasts indicate material that was transported and abraded before deposition, and cementation binds the grains into clastic sedimentary rock. Rounding and coarse grain size point to a relatively high-energy fluvial or coastal setting.

Question 40Physical Geography: Landforms, Tectonics and Drainage

At a destructive plate margin where oceanic lithosphere meets continental lithosphere, what sequence of features is expected inland from the boundary?

  1. Transform fault, then linear ridge
  2. Mid-ocean ridge, then abyssal plain
  3. Rift valley, then block mountains
  4. Trench, then volcanic mountain chain on the continental side Correct answer.

Explanation

The denser oceanic plate subducts, creating a deep trench at the boundary. Melting of the descending slab generates magma that rises through the continental plate, producing a volcanic mountain chain set back from the trench.

Question 41Physical Geography: Landforms, Tectonics and Drainage

A drainage basin has steep slopes, thin soils, sparse vegetation and intense summer storms. Which stream hydrograph response is most likely?

  1. A short lag time and a high peak discharge Correct answer.
  2. A long lag time and a low peak discharge
  3. A long lag time and a high baseflow
  4. A short lag time and a low peak discharge

Explanation

Steep slopes and thin soils allow rapid overland flow, and sparse vegetation removes little water by interception. Storm rainfall therefore reaches the channel quickly, producing a short lag and a high peak.

Question 42Physical Geography: Landforms, Tectonics and Drainage

A meander on a river floodplain is examined in cross-section. Which pattern of flow and deposition is expected?

  1. Uniform flow across the channel with equal erosion on both banks
  2. Fastest flow near the outer bank with erosion, and deposition on the inner bank forming a point bar Correct answer.
  3. Fastest flow near the inner bank with erosion, and deposition on the outer bank
  4. Slowest flow near the outer bank with deposition of coarse gravel

Explanation

Centrifugal force and secondary circulation push the fastest flow toward the outer bank, where erosion undercuts the bank and creates a river cliff. The slower water on the inner bank cannot carry as much load, so deposition builds a point bar.

Question 43Physical Geography: Landforms, Tectonics and Drainage

Which combination of conditions produces the most rapid chemical weathering of granite?

  1. Hot, arid climate with strong evaporation
  2. Cool, wet climate with seasonal frost
  3. Warm, wet climate with abundant rainfall and high temperature Correct answer.
  4. Cold, dry climate with frequent freezing

Explanation

Chemical weathering needs water as a reactant and warmth to speed reaction rates, so a hot humid climate maximises hydrolysis and solution. Cold or dry conditions slow these reactions even where some moisture is present.

Question 44Physical Geography: Landforms, Tectonics and Drainage

A river's discharge is measured as 12 m³/s and its channel cross-sectional area is 8 m². What is the mean velocity?

  1. 0.67 m/s
  2. 1.5 m/s Correct answer.
  3. 96 m/s
  4. 4 m/s

Explanation

Discharge equals cross-sectional area multiplied by mean velocity, so velocity equals discharge divided by area. Dividing 12 m³/s by 8 m² gives 1.5 m/s.

Question 45Physical Geography: Landforms, Tectonics and Drainage

Which statement best explains why a river deposits its load where its channel emerges from a steep mountain front onto a plain?

  1. The gradient and velocity fall, reducing competence and capacity Correct answer.
  2. Discharge increases sharply as tributaries join at the mountain front
  3. The river water becomes more acidic and dissolves its load
  4. The gradient rises, increasing the river's ability to carry sediment

Explanation

Leaving the steep uplands, the river loses gradient and its velocity falls, which lowers both competence and capacity. The load can no longer be transported and is deposited as an alluvial fan.

Question 46Physical Geography: Landforms, Tectonics and Drainage

Which feature is a direct result of glacial deposition rather than glacial erosion?

  1. A roche moutonnée
  2. A terminal moraine Correct answer.
  3. A cirque
  4. A hanging valley

Explanation

A terminal moraine is a ridge of unsorted till dumped at the maximum extent of an advancing glacier. It is built by deposition of debris carried at the ice front.

Question 47Physical Geography: Landforms, Tectonics and Drainage

A limestone region shows a cave system, sinking streams and dry valleys. Which combination of processes best accounts for these features?

  1. Abrasion by glacial ice moving over the limestone
  2. Carbonation solution along joints, enlarging underground drainage routes Correct answer.
  3. Deposition of till blocking surface channels
  4. Frost shattering of the limestone surface

Explanation

Rainwater with dissolved carbon dioxide forms weak carbonic acid, which dissolves calcium carbonate along joints and bedding planes. Enlarged fissures become cave systems, surface streams sink underground and valleys are left dry.

Question 48Physical Geography: Landforms, Tectonics and Drainage

Which sequence correctly orders the processes that transform loose sand into a clastic sedimentary rock?

  1. Cementation, weathering, deposition
  2. Deposition, compaction, cementation Correct answer.
  3. Metamorphism, deposition, compaction
  4. Compaction, melting, crystallisation

Explanation

Sediment is first deposited, then buried and compacted as overburden pressure reduces pore space. Mineral cement precipitated from groundwater then binds the grains into solid rock.

Question 49Physical Geography: Landforms, Tectonics and Drainage

A fold has its oldest exposed rocks in the centre and the strata dip away from the axis on both sides. Which structure is described?

  1. A thrust fault
  2. A syncline
  3. An anticline Correct answer.
  4. A normal fault

Explanation

In an anticline the strata arch upward, so erosion of the crest exposes the oldest beds in the core. The limbs dip outward away from the fold axis.

Question 50Physical Geography: Landforms, Tectonics and Drainage

Which evidence would best support the interpretation that a valley was occupied by a glacier rather than a river?

  1. A floodplain with meander scars and oxbow lakes
  2. A channel with well-rounded, sorted gravel on its bed
  3. A narrow V-shaped cross-profile with interlocking spurs
  4. A wide U-shaped cross-profile with truncated spurs and misfit streams Correct answer.

Explanation

Glaciers erode laterally as well as vertically, widening valleys into a U-profile and truncating the spurs that rivers leave interlocking. After retreat, small misfit streams occupy the over-deepened trough.