Geology 106 Sample Test 2 (1)

Why is the study of the age of the Earth essential for understanding Earth's geological history?

It sets a timeline for Earth's geological events.

Which evidence suggests that Earth's early atmosphere was reducing, not oxidizing?

The existence of banded iron formations.

How did water accumulate on Earth?

Through volcanic outgassing.

True or False: Earth's early atmosphere consisted primarily of nitrogen and oxygen.

False.

How does outgassing affect Earth's early atmosphere?

It contributed to the formation of oceans.

Which of the following was a result of the Great Oxygenation Event?

The mass extinction of anaerobic life.

What is the primary composition of a craton?

Metamorphic and igneous rocks.

What does the study of komatiites suggest about early Earth conditions?

Earth's mantle was much hotter than today.

What type of environment would most likely produce a banded iron formation (BIF)?

A deep ocean with little to no oxygen.

True or False: Komatiites are thought to be one of the oldest forms of volcanic rocks on Earth.

True.

What process formed the first continental crust on Earth?

Accretion.

Which fossilized structure is a key indicator of early microbial life?

Stromatolite.

Which is true about aerobic organisms?

They use oxygen to produce energy.

How do Black Smokers relate to early life?

They are evidence of life near volcanic activity.

True or False: Ediacaran fauna represent the first known multicellular life forms.

True.

Which process likely led to the rise of eukaryotic cells?

Endosymbiosis.

How does the presence of a craton help us understand Earth’s geological stability?

It has remained relatively undisturbed for billions of years.

Which of the following explains the formation of supercontinents like Pangea?

Convergence of tectonic plates over millions of years.

What is the Wilson Cycle?

The opening and closing of ocean basins through plate movements.

How does the study of cratonic sequences help reconstruct Earth’s past environments?

It reveals the timing of Earth's first biological organisms.

True or False: Rodinia was the first supercontinent to form on Earth.

False.

Which supercontinent came after Rodinia?

Pangea.

How do transgressions and regressions differ in Earth’s geological history?

Transgressions are caused by ocean water advancing; regressions by retreating.

What is the key characteristic of a mobile belt in tectonics?

A zone of active mountain building and plate collision.

True or False: Earth’s first organisms were likely simple, prokaryotic cells.

True.

Which type of fossil is used to study ancient behaviors or movements of organisms?

Trace fossil.

Why is the Phanerozoic eon significant in the fossil record?

It marks the era when complex life forms began to flourish.

What environmental factor played a key role in the Cambrian Explosion?

Increased atmospheric oxygen.

What is the role of taphonomy in the fossilization process?

It describes the environmental conditions during fossil formation.

True or False: The oldest known fossils are approximately 3.5 billion years old.

True.

What is the primary reason the study of marine ecosystems is vital to understanding early life?

Most early life forms were marine organisms.

Why were shelly fauna important in the evolution of life?

They marked the rise of multicellular life forms.

What is the significance of the Burgess Shale in paleontology?

It contains fossils that show early life diversity during the Cambrian period.

What environmental factor likely led to the first significant rise in atmospheric oxygen?

The evolution of photosynthesizing bacteria.

True or False: The Cambrian Explosion is characterized by a sudden increase in biodiversity.

True.

How did the supercontinent Pangea affect the climate?

It caused extreme temperature fluctuations across Earth.

What is the main cause of mountain building in tectonics?

Subduction zones and continental collisions.

How can fossils tell us about ancient climates?

By revealing the types of organisms that lived in specific regions.

Which of the following best defines a 'regression' in geological terms?

A decrease in sea level.

How does studying the geological history of mobile belts help us understand Earth's development?

It provides insight into past mountain-building events.

What key event is associated with the rise of prokaryotic life?

The development of photosynthesis.

What is a cratonic sequence chart used to study?

The timing and sequence of Earth’s geological events.

True or False: The formation of Pangea had no impact on Earth's climate or biota.

False.

Which process contributes to the formation of a mobile belt?

Plate tectonic movements and mountain building.

What can we infer about Earth's early crust from the study of komatiites?

It was much hotter than it is today.

How do fossils give insight into ancient ecosystems?

By showing us how life evolved in specific regions.

Which of the following is an example of a trace fossil?

A footprint.

Why is the study of taphonomy important for understanding the fossil record?

It helps explain how fossils were preserved.

How did the appearance of oxygen in Earth's atmosphere contribute to life?

It allowed for the development of complex life forms.

What is an example of the process of 'subduction' in plate tectonics?

The destruction of crust as one plate slides beneath another.

Why is the age of Earth important in understanding the history of life?

It sets a timeline for the evolution of organisms.

Which evidence supports the idea that Earth's early atmosphere was reducing rather than oxidizing?

The existence of banded iron formations.

What role did outgassing play in Earth's early atmosphere?

It contributed to the formation of Earth’s early oceans.

True or False: Komatiites are an indicator of an early hotter Earth.

True.

If the Great Oxygenation Event had not occurred, how might life have evolved differently?

The Earth would have remained dominated by anaerobic life.

Why is the concept of 'continental accretion' significant to the development of Earth's crust?

It accounts for the buildup of continents from oceanic material.

How does the fossilization process of a trace fossil differ from a body fossil?

Trace fossils show evidence of behavior, while body fossils show physical remains.

What does the existence of stromatolites indicate about early Earth environments?

They are evidence of photosynthetic activity in early oceans.

In the context of plate tectonics, what is meant by 'continental rifting'?

The stretching and thinning of continental crust.

How does studying cratonic sequences help us understand Earth's geological history?

They offer insights into the deposition of sediments over eons.

continental accretion

Continents grew more rapidly along their
margins

craton

the stable interior portion of a continent that has not been affected by significant tectonic activity for a long time.

banded iron formation

a sedimentary rock formation consisting of alternating layers of iron-rich minerals and silica, indicating ancient oceanic conditions.

continental red bed

a type of sedimentary rock that is typically reddish in color due to the presence of iron oxide, often found in continental environments.

Canadian shield

the exposed portion of the North American craton, characterized by ancient rocks and significant mineral resources.

great oxygenation event

a significant increase in Earth's atmospheric oxygen levels around 2.4 billion years ago, primarily due to photosynthetic microorganisms.

komatiite

a high-temperature volcanic rock that is rich in magnesium and iron, typically formed in the mantle and indicative of early Earth conditions.

outgassing

the release of gases from the Earth's interior, which contributed to the formation of the atmosphere and oceans.

platform

a stable, relatively flat region of the Earth's crust that has not been significantly deformed and is often covered by sedimentary rocks.

shield

a large area of exposed Precambrian crystalline rocks that forms the core of a continent, characterized by its stability and lack of significant tectonic activity.

aerobic

relating to processes or organisms that require oxygen to survive or function, often involved in biological respiration.

acritarchs

microscopic, organic-walled fossils that are typically found in marine sediments, dating back to the Proterozoic and Paleozoic eras. They are important for biostratigraphy and understanding ancient ecosystems.

Ediacaran Fauna

a group of diverse, soft-bodied organisms that existed during the Ediacaran Period, known for their unique shapes and potential early multicellular life forms.

endosymbiosis

the theory that explains the origin of eukaryotic cells from prokaryotic organisms, where one organism lives inside another, benefiting both.

eukaryotic cell

a type of cell with a nucleus and organelles, distinct from prokaryotic cells. Eukaryotic cells are found in animals, plants, fungi, and protists.

monomer

a small molecule that can join together with other similar molecules to form larger structures, such as polymers.

multi-celled organism

an organism composed of multiple cells that work together to perform functions necessary for life, such as in animals and plants.

polymer

a large molecule made up of repeating structural units (monomers) bonded together, forming substances like plastics, proteins, and nucleic acids.

prokaryotic cell

A single-celled organism that lacks a nucleus and membrane-bound organelles, typically smaller than eukaryotic cells. Includes bacteria and archaea.

stromatolite

A layered sedimentary structure formed by the activity of microbial communities, particularly cyanobacteria, often found in shallow marine environments

cratonic sequence

A major stratigraphic unit that represents a complete cycle of sedimentary deposition and erosion on a craton, typically spanning millions of years.

epeiric sea

A shallow sea that covers a continental shelf, often during periods of high sea level, allowing for extensive sediment deposition.

mobile belt

A tectonically active region where significant deformation occurs, typically associated with mountain building and orogenic processes.

orogeny

The process of mountain formation through tectonic forces, typically involving the folding, faulting, and uplift of the Earth's crust.

Pangea

a supercontinent that existed millions of years ago when all the continents were joined together.

Pannotia

a supercontinent that preceded Pangea, existing during the late Proterozoic era, characterized by the assembly of all landmasses.

Panthalassa

the vast ocean that surrounded Pangea, covering most of the Earth's surface during the late Paleozoic era.

regression

a geological process where sea levels fall, exposing land previously submerged underwater

Rodinia

a supercontinent that existed during the Neoproterozoic era, consisting of most of Earth's landmasses before Pannotia.

transgression

a geological process where sea levels rise, flooding land previously exposed.

Wilson Cycle

the cycle of ocean basin formation and closure, driven by plate tectonics.

benthos

the community of organisms living on or in the seabed, also known as the benthic zone.

body fossil

a fossilized remains of an organism, typically including bones, teeth, and shells, that provide insight into past life forms.

chordate

an animal that has a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail at some point in its development.

fossil

the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock

nekton

aquatic organisms that swim independently of water currents. They include fish, squid, sharks, and marine mammals.

plankton

the small and microscopic organisms drifting or floating in the sea or fresh water, consisting chiefly of diatoms, protozoans, small crustaceans, and the eggs and larval stages of larger animals

taphonomy

the branch of paleontology that deals with the processes of fossilization.

trace fossil

evidence of ancient life that are not the preserved remains of the organism itself

What are North America’s 4 Mobile Belts?

Appalachian, Duachita, Cordilleran, Franklin