2.4 C: Geology = the Changing Earth 2.4 Raising the Rockies Flashcards
What type of rock is shale?
A sedimentary rock originally laid down in nearly horizontal layers of fine sediment at the bottom of tropical seas
Fossil evidence from sites such as the Burgess Shale supports the sedimentary origin of shale.
What geological feature is highlighted in the text as being complex and beautiful?
Mount Michener
The photo of Mount Michener shows complex folds within beds of shale and limestone.
What major geological process is responsible for raising the floor of a tropical sea to become a mountain?
Plate tectonics
What significant event occurred in March 1964 in Alaska?
The Alaska Earthquake of 1964
What is the relationship between earthquakes and tectonic plate boundaries?
Earthquakes usually occur at the boundaries of crustal plates
What geological feature is associated with the asthenosphere?
Magma for volcanoes
What two types of geological features can help locate the edges of tectonic plates?
Major earthquakes and active volcanoes
Fill in the blank: Earth’s crust is comprised of a series of rigid crustal plates that move over the _______.
asthenosphere
True or False: Volcanoes only occur at the boundaries of tectonic plates.
False
Volcanoes sometimes occur at places not close to plate boundaries.
What type of rock layers are mentioned as being part of the Rocky Mountains?
Shale and limestone
What caused the build-up of stress along the southern coast of Alaska in the early 1960s?
The interaction between the Pacific Plate and the North American Plate
How can plotting volcanoes contribute to understanding tectonic plate boundaries?
It can provide valuable insights for mapping out the edges of crustal plates
What provided evidence for the theory of plate tectonics in the Atlantic Ocean?
Paleomagnetism
Paleomagnetism studies the magnetic properties of rocks to understand historical movement of tectonic plates.
What can the location of earthquakes and volcanoes produce?
A world map showing crustal plate boundaries
This mapping helps identify the edges of tectonic plates.
What is Pangaea?
A single supercontinent that formed in the late Paleozoic Era
Pangaea is significant in understanding the historical arrangement of Earth’s continents.
Who coined the name Pangaea and in what year?
Alfred Wegener in 1915
Wegener proposed the theory of continental drift, which laid the groundwork for plate tectonics.
What theory is considered a forerunner to the theory of plate tectonics?
The theory of continental drift
This theory suggests that continents have moved over geological time.
During which geological period did Alberta’s future economic wealth in petroleum begin to form?
Devonian Period
The Devonian Period is known for significant organic matter deposition.
What major geological event occurred during the Devonian Period involving Greenland and eastern Canada?
Collision with northern Europe
This collision initiated the formation of a single northern land mass.
What was the result of the collision between Greenland, eastern Canada, and northern Europe during the Devonian Period?
Formation of a mountain chain
Geologists refer to this mountain chain in the context of Plate Tectonics.
Which continents were already part of the huge southern land mass during the Devonian Period?
Africa, India, Australia, and South America
These continents were already combined into a single land mass.
Fill in the blank: The spaces between the pieces of this ancient continental jigsaw puzzle were _______.
closing
This refers to the gradual merging of landmasses during the Devonian Period.
During which geological period did Alberta’s future economic wealth in petroleum begin to form?
Devonian Period
The Devonian Period is known for significant organic matter deposition.
What major geological event occurred during the Devonian Period involving Greenland and eastern Canada?
Collision with northern Europe
This collision initiated the formation of a single northern land mass.
What was the result of the collision between Greenland, eastern Canada, and northern Europe during the Devonian Period?
Formation of a mountain chain
Geologists refer to this mountain chain in the context of Plate Tectonics.
Which continents were already part of the huge southern land mass during the Devonian Period?
Africa, India, Australia, and South America
These continents were already combined into a single land mass.
Fill in the blank: The spaces between the pieces of this ancient continental jigsaw puzzle were _______.
closing
This refers to the gradual merging of landmasses during the Devonian Period.
What significant event began during the Permian Period?
Reptiles began to diversify into a wide variety of forms
This diversification included the emergence of fierce carnivores.
Which fierce carnivore is mentioned as having roamed during the Permian Period?
Dimetrodons
Dimetrodons were known to search for prey in the equatorial landscape.
What does the fossil record indicate about the diversity of life during the Permian Period?
Life reached a rich level of diversity on both land and sea
This indicates a flourishing ecosystem.
What major geological formation was occurring by the end of the Permian Period?
The formation of the supercontinent Pangaea
This involved the northern and southern continents beginning to merge.
Approximately how many years ago did the events of the Permian Period take place?
250 million years ago
This timeframe marks significant geological and biological changes.
How many mass extinctions are documented in the fossil record?
Six mass extinctions
These extinctions are characterized by large-scale loss of biodiversity in a short time period.
What is the most significant mass extinction event recorded?
The end of the Permian Period, 250 million years ago
This event marks the greatest extinction of life in the fossil record.
At the end of which geological era did the greatest extinction occur?
The Paleozoic Era
The end of the Permian Period signifies the conclusion of this era.
What percentage of ocean species became extinct during the greatest extinction?
About 90%
This figure reflects the massive loss of marine biodiversity.
What percentage of land animal species became extinct during the greatest extinction?
Approximately 70%
This extinction event had a profound impact on terrestrial life.
Fill in the blank: The fossil record contains evidence of _______ mass extinctions.
[six mass extinctions]
True or False: The end of the Permian Period is the least significant extinction event recorded.
False
The end of the Permian Period is noted as the most significant extinction event.
What time period does the greatest extinction mark in millions of years ago?
250 million years ago
What are the six largest extinction events recorded in the fossil record identified as?
Letters A through F
What significant event occurred at the end of the Paleozoic Era?
Species of animals that had existed since the Cambrian Explosion died or had their numbers greatly reduced
Which group of organisms was hardest hit during the end of the Paleozoic Era?
Marine invertebrates
What types of coral became extinct at the end of the Paleozoic Era?
Simple colonial corals
Which species became extinct during the end of the Paleozoic Era?
All trilobite species
Since when have scientists known about the Permian Extinction?
Since the eighteenth century
What are the six largest extinction events recorded in the fossil record identified as?
Letters A through F
What significant event occurred at the end of the Paleozoic Era?
Species of animals that had existed since the Cambrian Explosion died or had their numbers greatly reduced
Which group of organisms was hardest hit during the end of the Paleozoic Era?
Marine invertebrates
What types of coral became extinct at the end of the Paleozoic Era?
Simple colonial corals
Which species became extinct during the end of the Paleozoic Era?
All trilobite species
Since when have scientists known about the Permian Extinction?
Since the eighteenth century
What is a potential cause of mass extinction events on Earth?
A deep impact caused by a comet or a very large asteroid colliding with Earth
This could have worldwide implications similar to nuclear war.
What worldwide implications might result from a comet or asteroid impact?
Massive firestorms and enough dust blasted into the atmosphere to block out sunlight for months
These conditions would significantly affect the planet’s climate and ecosystems.
What is the name of the mass extinction event at the end of the Cretaceous Period?
Mass extinction F
This event is believed to have been primarily caused by a collision with a comet or asteroid.
What are researchers currently investigating regarding the Permian Extinction?
Evidence that a similar impact event caused the Permian Extinction
This investigation aims to identify parallels between the two extinction events.
What alternative cause has been suggested for the Permian Extinction?
Massive volcanic activity
This activity is believed to have occurred in what is now Siberia.
What is a potential cause of mass extinction events on Earth?
A deep impact caused by a comet or a very large asteroid colliding with Earth
This could have worldwide implications similar to nuclear war.
What worldwide implications might result from a comet or asteroid impact?
Massive firestorms and enough dust blasted into the atmosphere to block out sunlight for months
These conditions would significantly affect the planet’s climate and ecosystems.
What is the name of the mass extinction event at the end of the Cretaceous Period?
Mass extinction F
This event is believed to have been primarily caused by a collision with a comet or asteroid.
What are researchers currently investigating regarding the Permian Extinction?
Evidence that a similar impact event caused the Permian Extinction
This investigation aims to identify parallels between the two extinction events.
What alternative cause has been suggested for the Permian Extinction?
Massive volcanic activity
This activity is believed to have occurred in what is now Siberia.
What was the largest volcanic eruption of the twentieth century?
Mount Pinatubo in the Philippines
This eruption occurred in 1991.
What was the temperature reduction caused by the Mount Pinatubo eruption?
0.5°C reduction in average global temperature
This occurred a year after the eruption due to ash ejection.
How much ash was ejected into the atmosphere by Mount Pinatubo?
More than 20 million tonnes
This significant amount of ash contributed to global cooling.
What type of volcanic activity characterized the eruptions at the end of the Permian Period?
Lava flows and large amounts of ash deposits
These eruptions in ancient Siberia were very explosive.
How long did the explosive eruptions in ancient Siberia last?
Hundreds of thousands of years
Geological evidence indicates prolonged volcanic activity.
What effect did the ash from Siberian volcanoes have on global temperatures?
Blocked sunlight from reaching the surface
This caused a global drop in temperatures.
What is notable about the ash from modern volcanoes?
It can circle Earth for years before settling out
This prolongs the impact of volcanic eruptions on climate.
What significant climate change event was caused by the eruption of Mount Tambora?
The year without a summer (1816)
This was due to a cool spring and summer following the eruption.
What happened to the growing season for crops in Europe and North America in 1816?
It was shortened and some regions suffered famine
The effects of the eruption impacted agricultural yields.
What was the first part of the Mesozoic Era?
The Triassic Period
The Triassic Period marked the beginning of the Mesozoic Era.
What geological activity occurred during the Triassic Period?
The North American Plate continued its movement to the north and west
This movement caused portions of the plate to be alternately above and below sea level.
What type of vegetation grew in Alberta during the Triassic Period?
Swampy areas and forests
These areas developed as the Pacific Ocean retreated from Alberta.
What evidence indicates the presence of early mammals during the Triassic Period?
Fossil evidence from forests
Early mammals inhabited the forests that grew in coastal areas.
What geological feature was formed from the vegetation of the Triassic forests and swamps?
Coal deposits
Over geological time, the vegetation became coal deposits.
What significant geological event occurred at the end of the Triassic Period?
Pangaea was coming apart, causing sea levels to rise
This event led to much of the North American continent being submerged.
What triggered another mass extinction at the end of the Triassic Period?
Possible collisions by meteorites
This mass extinction corresponds to the one labeled E in geological studies.
What was the significance of the mass extinction at the end of the Triassic Period?
It created vacancies in the food chain
These vacancies allowed dinosaurs to take over.
During which period did dinosaurs begin to flourish?
The Jurassic Period
Dinosaurs developed rapidly during this time.
What does the fossil evidence from the Jurassic Period indicate?
The relationship between land masses during the Mesozoic Era
Similar early Jurassic dinosaur fossils are found globally.
What geological period is associated with the break-up of Pangaea?
Middle of the Jurassic Period
This period marks significant geological changes, including continental drift.
Which direction did North America drift during the Jurassic Period?
West
North America moved away from Africa during this time.
What began colliding with the western shore of the North American Plate?
Arcs of volcanic islands
These volcanic islands were integral to the formation of the western cordillera.
What geological process occurred with the tectonic plate carrying the volcanic islands?
Subduction
The plate was pushed under the advancing North American Plate.
What geological features were created as a result of the subduction process?
Lifting, folding, and thrusting of the North American Plate
This process contributed to the formation of mountain ranges.
What similarities do geologists observe between present-day southern Alaska and late Mesozoic Alberta?
Geological processes involving earthquakes and volcanoes
Both regions experienced significant tectonic activity.
What happened to the slivers of continental crust from the volcanic islands?
They became welded to the western coast of North America
This process contributed to the geological evolution of the continent.
What did Alberta lose during the geological changes?
Its Pacific coastline
As new landforms were created, the coastline shifted.
What was being added to the North American continent during this time?
The continental crust that became British Columbia
This addition was part of the larger geological reshaping of the area.
What type of activity is characteristic of subduction?
Volcanic activity
This includes the pouring of magma onto the surface.
What mountain ranges were formed as a result of geological processes discussed?
Mountain ranges from western Alberta through British Columbia to the Pacific coast
These ranges are remnants of the tectonic and volcanic activity.
Fill in the blank: The geological processes included raising ocean beds, welding island arcs, and _______.
flowing magma from volcanic activity
This highlights the dynamic nature of Earth’s geological history.
What geological feature was created on the east side of the Rocky Mountains?
An inland sea
The inland sea was formed due to the sagging of Earth’s crust caused by the weight of the Rocky Mountains.
What caused the Earth’s crust to sag, allowing ocean water to rush into the inland sea?
The great weight of the Rocky Mountains
This sagging created a basin that allowed ocean water to enter from both the north and south.
From which two locations did sediment flow into the inland sea?
- Precambrian Shield (east)
- Rising mountains (west)
Sediment from both locations contributed to the formation of deltas, swamps, and forests.
During which geological periods did the sediments create a vast network of deltas, swamps, and forests?
Late Jurassic and Cretaceous periods
These environments became habitats for a variety of dinosaurs.
What geological process occurred due to plate collisions on the west coast during the late Cretaceous Period?
Another period of compression
This compression further affected the geological structure of the region.
What was the net effect of the geological processes described in the text?
- The inland sea was uplifted and drained
- Existing mountains were pushed up higher
- Main ranges, front ranges, and foothills were formed
These processes also led to significant geological features in the region.
What significant geological feature can be seen in many mountains near Banff and Jasper?
Folded rock layers
These folded layers are a visible result of the compression caused by the collision of tectonic plates.
What is a thrust fault?
A type of fault where older rocks are pushed above younger rocks
This geological feature is often associated with mountain-building processes.
What was the time frame for the formation of the Rocky Mountains?
170 to 55 million years ago
This time frame includes significant geological activity that shaped the mountains.
What effect did the weight of rock sheets being added from the west have on the basin?
It caused the basin to gradually sink
This sinking offset the sediment flow into the inland sea.
True or False: By the late Cretaceous Period, the Atlantic Ocean was widening and continents were moving toward their modern positions.
True
This movement is part of the ongoing process of plate tectonics.
What is the last period of the Mesozoic Era?
The Cretaceous Period
It is marked by significant geological and biological changes.
What major event is the Cretaceous Period known for?
A mass extinction
Nearly every land animal with a mass greater than 25 kg became extinct.
What happened to ammonites during the Cretaceous-Tertiary mass extinction?
They became extinct
It marked the end of the line for ammonites.
What happened to plankton during the Cretaceous-Tertiary mass extinction?
Nearly half of the different varieties became extinct
The extinction of some plankton species is thought to have caused the collapse of some oceanic food chains.
What geological theory provides context for significant events in Alberta’s history?
Plate tectonics
It helps in understanding the geological events of the Paleozoic and Mesozoic eras.
How can the boundaries between tectonic plates be determined?
By plotting the locations of earthquakes and volcanoes on a world map
This method helps visualize the current positions of tectonic plates.
What was the supercontinent called that existed in the late Paleozoic Era?
Pangaea
Earth’s continental crust was fused into this single supercontinent.
What happened to Pangaea during the Mesozoic Era?
It began to break up
This breakup had significant geological impacts.
What geological feature resulted from the collision of the North American Plate and volcanic islands?
The mountainous terrain of British Columbia and western Alberta
These collisions shaped the current landscape of the region.
What is suggested by the fossil record about Pangaea’s formation and breakup?
It occurred during the two largest mass extinctions in Earth’s history
This correlation is an area of ongoing research.
True or False: The causes of mass extinctions remain a well-understood area of study.
False
The possible causes for these mass extinctions remain an area of intense research.
