Earth Science

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Questions and Answers

What phenomenon occurs when the rate of sea-floor spreading exceeds the rate of subduction?

The ocean remains constant

The ocean shrinks

The sea floor disappears

The ocean gets wider (correct)

Which stage in the Wilson Cycle is characterized by the formation of rift valleys?

Embryonic (correct)

Juvenile/Young

Mature

Declining

What is the defining feature of the 'Mature' stage in the evolution of ocean basins?

Broad ocean basins with developing trenches (correct)

Formation of embryonic rift valleys

Formation of mountain chains

Beginning of descent into subduction

Which ocean is shrinking according to the described processes of sea-floor formation and subduction?

Pacific Ocean Signup and view all the answers

What does the term 'Suturing' refer to in the context of ocean basin evolution?

The collision of continental plates forming mountain ranges Signup and view all the answers

What marks the beginning of the Mesozoic era?

The diversification of life forms Signup and view all the answers

Which period of the Paleozoic era is known as the 'age of fishes'?

Devonian period Signup and view all the answers

What significant event occurred approximately 200 million years ago during the Mesozoic era?

Pangaea began to break apart Signup and view all the answers

During which period did the first terrestrial life emerge?

Silurian period Signup and view all the answers

Which of the following statements is true regarding the Cenozoic era?

It includes two periods and seven epochs Signup and view all the answers

What was a significant marine event during the Ordovician period?

Marine invertebrates flourished Signup and view all the answers

What major life forms began to appear during the Jurassic period of the Mesozoic era?

Giant reptiles like dinosaurs Signup and view all the answers

What climate change influenced the onset of the Cenozoic era?

Temperature drop leading to an ice age Signup and view all the answers

What significant event marks the beginning of the Cenozoic Era?

Continents nearing present-day positions Signup and view all the answers

Which of the following statements describes sedimentary rocks?

They can contain fossils from organisms. Signup and view all the answers

What is relative dating primarily used for?

To compare the age of various objects. Signup and view all the answers

Which principle states that in undisturbed layers of rock, the younger layers are found above the older ones?

Law of Superposition Signup and view all the answers

How do modern humans fit into the timeline of hominid evolution?

They emerged around 0.2 million years ago. Signup and view all the answers

Which of the following events did NOT occur during the Cenozoic Era?

First appearance of amphibians Signup and view all the answers

What is the role of sediment in the formation of certain rock types?

Sediment layers compress and harden over time. Signup and view all the answers

What major glacial event began 2 million years ago during the Cenozoic Era?

Global ice ages Signup and view all the answers

What does the term 'fossil' refer to in geological terms?

The remains of ancient life preserved in rock. Signup and view all the answers

Which type of rock is formed from particles of gravel, sand, and mud?

Sedimentary rock Signup and view all the answers

What characterized the Hadean eon in relation to the Earth's surface conditions?

Chaotic environment due to asteroid and meteorite bombardment Signup and view all the answers

Which of the following statements is true regarding the Proterozoic eon?

Oxygen levels reached approximately 3% of the atmosphere. Signup and view all the answers

What was a significant consequence of the emergence of photosynthetic bacteria during the Archean eon?

The release of oxygen into the atmosphere Signup and view all the answers

Which group of reptiles flourished during the Permian period, ultimately leading to the rise of mammals?

Synapsids Signup and view all the answers

What does the term 'mass extinction' refer to?

A higher than average rate of extinction of many species in a short period Signup and view all the answers

Which of the following eons is characterized by the emergence of eukaryotes?

Proterozoic eon Signup and view all the answers

During which period did giant insects, such as dragonflies, first appear?

Carboniferous period Signup and view all the answers

What is the main significance of William Smith's observations in geology?

He identified that rock layers contain distinct fossil assemblages. Signup and view all the answers

Which period did Charles Lyell focus on when subdividing geologic time?

Tertiary Period Signup and view all the answers

What was a critical environmental factor in the Phanerozoic eon?

The formation of a protective ozone layer Signup and view all the answers

Which of the following statements accurately describes the Paleozoic Era?

Includes the significant carboniferous and permian periods Signup and view all the answers

What does the term 'half-life' refer to in geology?

The time required for an isotope to lose half of its radioactivity. Signup and view all the answers

What major change occurred at the end of the Paleozoic Era?

The Permian-Triassic extinction event Signup and view all the answers

Which eon is also referred to as the 'Eon of Hidden Life'?

Pre-cambrian Eon Signup and view all the answers

Which of the following best describes the relationship between the geological time scale and mass extinctions?

Mass extinctions help to define boundaries in the geological time scale. Signup and view all the answers

Which era is characterized by the dominance of dinosaurs?

Mesozoic Era Signup and view all the answers

In what way did photosynthetic microorganisms influence Earth's atmosphere during the Pre-cambrian?

They contributed to the formation of the ozone layer. Signup and view all the answers

What relationship exists between the Phanerozoic Eon and the development of complex life forms?

The Phanerozoic Eon is marked by the first appearances of multicellular life. Signup and view all the answers

Which of the following periods is part of the Mesozoic Era?

Triassic Period Signup and view all the answers

Who is associated with the early contributions to the geological time scale alongside William Smith?

Nicholas Steno Signup and view all the answers

Study Notes

Exogenic and Endogenic Processes

Exogenic processes occur near the Earth's surface, driven by gravity and atmospheric forces.
Weathering is the breakdown of rocks, soil, and minerals.

Types of Weathering

Physical/Mechanical Weathering: Breaks rocks apart without changing their chemical composition.
- Frost Wedging: Repeated freezing and thawing of water in cracks.
- Salt Crystal Growth: Water evaporating from cracks, causing salt crystals to grow and break the rock.
- Abrasion: Rocks wearing away due to collisions with other particles.
- Thermal Expansion: Variation in temperature causing rocks to expand and contract.
- Pressure Release: Layers above a rock being removed, decreasing pressure and causing it to break.
Chemical Weathering: Changes the molecular structure of rocks and soil; dissolving or decomposing.
- Solution/Dissolution: Acidic rainwater dissolving minerals in rocks.
- Hydrolysis: Acidic water breaking down rocks into clay and soluble salts.
- Oxidation: Reaction of a substance with oxygen.
- Biological Activity: Animals, plants, and microorganisms break down rocks through mechanical processes.

Agents of Weathering

Water: Breaks down rocks through its flow and chemicals.
Wind: Carries sand and small rocks that scratch the rock surface
Glaciers: Shapes the Earth's landscape.
Gravity: A strong force that drives erosion and deposition.

Factors Affecting Weathering

Climate: Mechanical and chemical weathering are more rapid in high-temperature regions.
Rock type: Different rocks have varying resistance to weathering.
Slope: Steeper slopes will experience weathering faster.
Rock Structure: Rock cracks make weathering more likely.

Mass Wasting

Movement of large rock fragments down slopes due to gravity.

Erosion

Soil and rock particles are moved away by wind, water, or ice.

Deposition

Process where eroded sediments are dropped off by agents of erosion.

Continental Drift Theory

Continents were once joined in a single landmass, Pangaea, and have drifted apart.
Evidences include:
- Continental Jigsaw Puzzle
- Fossil Correlation
- Rock and Mountain Correlation
- Paleoclimate Data

Wegener's Problem

Couldn't explain the force causing continental drift.

Seafloor Spreading

The continuous process of the Earth's lithospheric plates moving apart, creating new seafloor at mid-ocean ridges.

Plate Tectonic Theory

Earth's lithosphere consists of plates moving slowly over the mantle.
Causes geologic phenomena like earthquakes and volcanoes.

Reasons for Plate Movement

Convection currents in the mantle.
Ridge push.
Slab pull.

Structure of Ocean Basins

Continental Margins (continental rise, shelf, and slope)
Deep Sea floor (abyssal hill, plain, seamount, guyots, trenches, and submarine ridges)
Mid-oceanic ridges (mountain chains with rift valleys).

Wilson Cycle

Cyclical opening and closing of ocean basins due to plate movement
Embryonic, Juvenile/Young, Mature, Declining, Terminal phases

Evolution of Ocean Basins

Ocean basins have grown and been consumed throughout Earth's history.
Events led to current shapes: breakup of supercontinents, continental drifting, rifting, and subduction.

Stratigraphical Rock Formation

Layers of stratified rocks are called strata
Layers can be dated based on relative age using principles of superposition, original horizontality, crosscutting relations, faunal succession.
Law of Superposition: Younger rocks above older ones if layers not disturbed.
Absolute dating (radiometric dating) measures the actual age of rocks using radioactive isotopes.

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Description

Explore the fundamental concepts of exogenic and endogenic processes impacting the Earth's surface. This quiz covers various types of weathering, including physical and chemical processes, and their effects on rocks and soil. Test your knowledge on how these geological phenomena shape our planet.