**WEATHERING, EROSION, GLACIATION, & FOSSILS**
Massachusetts Standards:
Describe how the movement of the earth’s crustal plates causes both slow changes in the earth’s surface (e.g.,
formation of mountains and ocean basins) and rapid ones (e.g., volcanic eruptions and earthquakes).
Describe and give examples of ways in which the earth’s surface is built up and torn down by natural
processes, including deposition of sediments, rock formation, erosion, and weathering.
Explain and give examples of how physical evidence, such as fossils and surface features of glaciation,
supports theories that the earth has evolved over geologic time.
NOTES
EARTH’S HISTORY: Shaping of Earth’s Surface-then to now
I.
Plate Tectonics-plate boundaries (convergent, divergent, transform)
A. Slow changes-mountain formation, creation of ocean basins, etc.
B. Fast changes-volcanic eruptions, earthquakes
II. Natural Processes (builds up & tears down earth’s surface)
A. Weathering (rock dissolves; breaking bigger rocks into smaller ones)
1. Mechanical-freeze/thaw, salt
2. Chemical-oxidation (“rust”), acidification (dissolving limestone), hydrolysis (expansion)
3. Biological-animals, plants
B. Erosion (rocks & sediments picked up & moved to another place; Latin for “gnawing away”; forms
many features such as mountain peaks, valleys, coastlines; fossils unearthed in sedimentary rock by
erosion)
1. Water (one of most powerful forces)-rain, rivers, waves, floods
2. Wind (deflation-carry away, abrasion-strike land & break more)
3. Gravity-landslides
4. Ice/Glaciers-giant rivers of ice
C. Glaciers (thick mass of ice covering large area of land; 10% of earth; weight from snow turns to
solid ice; 100s of years to form)
1. Glaciers move b/c of weight-moves downhill (few ft/yr or several ft/day)
2. Many types
3. Features (ex. crevasses, head, terminus)
4. Changes land creating features (arête, curque, drumlin, fjord, horn, moraine, tarn)
D. Fossils (preserved remains or impressions of living organisms; learn about past history of life)
1. Several ways to form fossils (amber, carbonization, casts/molds, freezing, mummification,
permineralization)
2. Body fossils (parts of real body like teeth & bones) or Trace fossils (impressions)
3. Mostly in sedimentary rocks b/c temp & pressure of metamorphic & igneous would
destroy fossils
4. Index fossils-used to ID/define geologic periods; animal evolve over time-only around for
particular time in history so can correlate layers
MCAS Multiple Choice Questions:
The satellite image below shows a natural feature on Earth’s surface. The feature is marked X on the image.
Which action most likely helped form feature X?
A. Wind blew sand from the beach into large piles.
B. Sediments were deposited where the river met the ocean.
C. Waves pushed mud from the bottom of the ocean onto land.
D. Land was exposed when water was pulled offshore during low tide.
The “Ring of Fire” is a long chain of volcanoes that encircles the Pacific Ocean. Which of the following is the best explanation
for the arrangement of these volcanoes?
A. They outline the crater caused by the impact of an asteroid.
B. They follow the shape of the adjacent tectonic plates under the sea.
C. One volcano usually triggers a second volcano with its hot magma.
D. Volcanoes always form in rings because of underwater convection currents.
Which of the following processes usually takes the longest amount of time?
A. Hot lava cools and forms new rock.
B. Water vapor condenses to form a cloud.
C. A seismic wave travels through the mantle.
D. An ocean basin forms between two continents.
Scientists found evidence of past glacial activity in Massachusetts. Which of the following conclusions is best supported by this
evidence?
A. Sea levels were much higher in the past.
B. The climate on Earth has changed over time.
C. Total numbers of organisms on Earth have changed over time.
D. The total amount of radiation from the Sun was much higher in the past.
Which of the following are formed when two crustal plates collide with one another?
A. hot spots
B. rift valleys
C. mountain ranges
D. mid-ocean ridges
Which of the following provides the best evidence that Earth has evolved over geologic time?
A. coral reefs that slowly changed size
B. desert sand dunes that were shaped by winds
C. deposits of sediment found at the mouth of a river
D. rock containing fossilized seashells found on a mountaintop
Open Response: The diagram below shows three main layers that compose Earth. The layers are labeled X, Y, and Z.
a.
b.
c.
d.
Identify each of the three layers of Earth (X, Y, and Z) labeled in the diagram.
Describe one characteristic of the layer labeled X.
Describe one characteristic of the layer labeled Y.
Describe one way that the layer labeled Y interacts with the layer labeled Z.
The Appalachian Mountains, which extend from Canada to Alabama, were much taller in the past than they are today. Which of
the following two processes are most responsible for the decrease in the height of the Appalachian Mountains?
A. weathering and erosion
B. sedimentation and flooding
C. volcanic eruptions and landslides
D. tectonic collisions and earthquakes
Seafloor spreading provides evidence of which of the following Earth processes?
A. erosion of coastlines
B. weathering of mountains
C. movement of crustal plates
D. formation of sedimentary rocks