Changing Earth Surface - Middle School Earth and Space Science
Card 1 of 25
Which process forms rounded pebbles in a river: weathering, erosion, or deposition?
Which process forms rounded pebbles in a river: weathering, erosion, or deposition?
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Weathering (abrasion). Water tumbling rocks against each other smooths their surfaces.
Weathering (abrasion). Water tumbling rocks against each other smooths their surfaces.
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What landform provides evidence of long-term deposition where a river enters an ocean or lake?
What landform provides evidence of long-term deposition where a river enters an ocean or lake?
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Delta. Triangular sediment buildup shows continuous deposition.
Delta. Triangular sediment buildup shows continuous deposition.
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Which relative-age rule states: a fault or igneous intrusion is younger than the rocks it cuts?
Which relative-age rule states: a fault or igneous intrusion is younger than the rocks it cuts?
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Principle of cross-cutting relationships. Features must exist before being cut through.
Principle of cross-cutting relationships. Features must exist before being cut through.
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Which relative-age rule states: in undisturbed layers, older rocks are below younger rocks?
Which relative-age rule states: in undisturbed layers, older rocks are below younger rocks?
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Law of superposition. Sediments deposit sequentially, oldest at bottom.
Law of superposition. Sediments deposit sequentially, oldest at bottom.
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What does a sedimentary rock layer (stratum) most directly indicate about past conditions?
What does a sedimentary rock layer (stratum) most directly indicate about past conditions?
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Sediments were deposited over time, often in water or wind environments. Layers form from particles settling in specific environments.
Sediments were deposited over time, often in water or wind environments. Layers form from particles settling in specific environments.
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What is a fossil, and why is it evidence of surface change over time?
What is a fossil, and why is it evidence of surface change over time?
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Preserved remains/trace; shows past environments different from today. Past life forms preserved in rock reveal environmental changes.
Preserved remains/trace; shows past environments different from today. Past life forms preserved in rock reveal environmental changes.
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What is mass wasting?
What is mass wasting?
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Downhill movement of rock and soil due to gravity. Gravity alone moves material downslope without other agents.
Downhill movement of rock and soil due to gravity. Gravity alone moves material downslope without other agents.
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Which agent of erosion is most likely if you observe talus piles at the base of a steep slope?
Which agent of erosion is most likely if you observe talus piles at the base of a steep slope?
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Gravity (mass wasting). Gravity pulls loose rock downslope, forming debris piles.
Gravity (mass wasting). Gravity pulls loose rock downslope, forming debris piles.
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Which term means rock is broken down but not moved: weathering, erosion, or deposition?
Which term means rock is broken down but not moved: weathering, erosion, or deposition?
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Weathering. Breaking occurs in place without transportation.
Weathering. Breaking occurs in place without transportation.
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Which agent of erosion is most likely if you observe V-shaped valleys and meandering streams?
Which agent of erosion is most likely if you observe V-shaped valleys and meandering streams?
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Running water. Rivers cut V-shaped valleys and create winding channels.
Running water. Rivers cut V-shaped valleys and create winding channels.
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Which agent of erosion is most likely if you observe sand dunes and wind-shaped rocks?
Which agent of erosion is most likely if you observe sand dunes and wind-shaped rocks?
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Wind. Wind sorts sand into dunes and abrades exposed rocks.
Wind. Wind sorts sand into dunes and abrades exposed rocks.
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Which evidence best supports coastal erosion over time when comparing photos years apart?
Which evidence best supports coastal erosion over time when comparing photos years apart?
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Shoreline retreat and loss of beach or cliff material. Waves remove material, causing land to move inland.
Shoreline retreat and loss of beach or cliff material. Waves remove material, causing land to move inland.
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What is uplift, and how does it change Earth’s surface over time?
What is uplift, and how does it change Earth’s surface over time?
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Rising of crust; increases elevation and can increase erosion rates. Tectonic forces raise land, exposing it to weathering.
Rising of crust; increases elevation and can increase erosion rates. Tectonic forces raise land, exposing it to weathering.
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What is the best evidence that frost wedging (ice) is breaking rock apart?
What is the best evidence that frost wedging (ice) is breaking rock apart?
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Cracks widened with angular fragments at the base of slopes. Water freezes in cracks, expands, and breaks rock mechanically.
Cracks widened with angular fragments at the base of slopes. Water freezes in cracks, expands, and breaks rock mechanically.
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What is the best evidence that chemical weathering is occurring on a statue or headstone?
What is the best evidence that chemical weathering is occurring on a statue or headstone?
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Pitting and surface dissolution on limestone or marble. Acid rain reacts with carbonate minerals, creating holes.
Pitting and surface dissolution on limestone or marble. Acid rain reacts with carbonate minerals, creating holes.
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Which process is indicated when a river slows and drops sediment at its mouth?
Which process is indicated when a river slows and drops sediment at its mouth?
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Deposition. Reduced velocity causes rivers to drop their sediment load.
Deposition. Reduced velocity causes rivers to drop their sediment load.
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What is a fossil, and why is it useful evidence for past surface environments?
What is a fossil, and why is it useful evidence for past surface environments?
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Preserved remains/traces; indicates past conditions and depositional setting. Shows what lived there and environmental conditions.
Preserved remains/traces; indicates past conditions and depositional setting. Shows what lived there and environmental conditions.
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Which plate boundary most often creates mountain ranges through compression and uplift?
Which plate boundary most often creates mountain ranges through compression and uplift?
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Convergent plate boundary. Colliding plates compress and fold crust upward.
Convergent plate boundary. Colliding plates compress and fold crust upward.
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Which principle states that in undisturbed sedimentary layers, the oldest layer is at the bottom?
Which principle states that in undisturbed sedimentary layers, the oldest layer is at the bottom?
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Law of Superposition. Sediments settle in order, creating a time sequence.
Law of Superposition. Sediments settle in order, creating a time sequence.
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If Layer A lies above Layer B in undisturbed rock, which layer is older?
If Layer A lies above Layer B in undisturbed rock, which layer is older?
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Layer B. Lower layers formed first in undisturbed sequences.
Layer B. Lower layers formed first in undisturbed sequences.
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What is an unconformity?
What is an unconformity?
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A gap in the rock record caused by erosion or nondeposition. Missing time represents erosion or no sediment deposited.
A gap in the rock record caused by erosion or nondeposition. Missing time represents erosion or no sediment deposited.
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What surface evidence most directly supports that an unconformity formed between two rock layers?
What surface evidence most directly supports that an unconformity formed between two rock layers?
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An irregular erosional boundary separating older and younger layers. Erosion creates uneven surfaces between rock units.
An irregular erosional boundary separating older and younger layers. Erosion creates uneven surfaces between rock units.
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Which landform is strongest evidence of wind deposition: delta, dune, or moraine?
Which landform is strongest evidence of wind deposition: delta, dune, or moraine?
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Dune. Wind deposits sand in characteristic mound shapes.
Dune. Wind deposits sand in characteristic mound shapes.
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Which agent of erosion is most directly supported by V-shaped valleys and meandering streams?
Which agent of erosion is most directly supported by V-shaped valleys and meandering streams?
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Running water (rivers/streams). Flowing water cuts narrow valleys and creates curved channels.
Running water (rivers/streams). Flowing water cuts narrow valleys and creates curved channels.
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Which agent of erosion is most directly supported by U-shaped valleys and moraines?
Which agent of erosion is most directly supported by U-shaped valleys and moraines?
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Glaciers (ice). Ice carves wide, rounded valleys and deposits unsorted debris.
Glaciers (ice). Ice carves wide, rounded valleys and deposits unsorted debris.
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