Lecture #4 (Lithosphere) Flashcards
How long ago was the Big Bang?
13.8 billion YBP (Years Before Present)
What is thought to have caused the Big Bang?
Some irregularity – think of the quote, “We are all star dust”
What is the name of the galaxy that we live in?
Milky Way
When did the first galaxies and stars form?
About a few hundred million years (Ma) after the Big Bang
How long ago did our solar system and sun form?
5 Ga (~9 Gas after the Big Bang)
At 4.54 Ga what was formed?
The Earth
What is the Theia Impact theorized to have caused/formed? And when?
The moon; 4.5 Ga
The oldest known rock on Earth is ____ Ga and is located where?
4.03; Canadian Shield
What does LUCA stand for?
Last Universal Common Ancestor of life (start of life on Earth)
How many years is Ga?
Billions of years
How many years is Ma?
Millions of years
LUCA was about how many years ago? And during what period was this in?
~3.8 Ga; Archean Period
What is the lithosphere?
The solid outer part of Earth including the crust and the upper part of the mantle
What are the 4 different eras in geological time scales of planet Earth?
- Cenozoic (present)
- Mesozoic (middle)
- Paleozoic (ancient)
- Precambrian (oldest of old)
What geological time eon, era, period, and epoch are we currently in?
Phanerozoic (Eon); Cenozoic (Era); Quaternary (Period); Holocene (Epoch)
The Precambrian era was how many years ago?
2.5 to 4.54 Ga
What 2 Epoch’s are within the Quaternary Period?
Holocene (today) & Pleistocene (11.8 Ka)
What is the order of the geological time scale eras from most recent to oldest?
Cenozoic (today - 66 Ma) –> Mesozoic (66 Ma - 252 Ma) –> Paleozoic (252 Ma - 541 Ma) –> Precambrian (541 Ma - 4.54 Ga)
Cenozoic; Mesozoic; Paleozoic; Precambrian
What eon are we currently in?
Phanerozoic
When was the Quaternary period?
Currently (present day)
Life has been on the planet since the ending of the Precambrian eon, when did this eon end?
541 Ma
What are the 2 sub-types of the Igneous lithosphere?
Volcanic rocks & Plutonic rocks
What is the igneous lithosphere?
The farthest layer from the core that has solidified from lava or magma; these rocks can be old, such as the Canadian Shield, to very recent, such as in Western Canada
What type of rocks are formed from lava that flows on the Earth’s surface?
Volcanic
What type of rocks are formed from magma cooling and solidifying underground?
Plutonic
What is a shield (in relation to the lithosphere)?
A large area of exposed Precambrian-age igneous and metamorphic rocks that form tectonically stable areas (cratons); Age of rocks is > 570 Ma & sometimes 2 to over 4 Ga.
What type of rocks form by recrystallizing minerals under high pressure or temperature (common to the Canadian Shield)?
Metamorphic Rocks
What type of rocks form from pieces of other rocks ‘glued’ together (or organics like coal) or by minerals being precipitated from water?
Sedimentary rocks
Between Metamorphic and Sedimentary rocks, which one is older?
Metamorphic
What is a craton?
A part of a continent that is stable, forming the central mass of a continent (i.e. the older ‘basement’ or foundation rocks)
When did Earth’s continents start forming?
~3 Ga
The North American lithosphere is approximately how many kilometers thick?
250 km
When the Earth cooled around __ Ga and within the last ___ Ma the cratons stopped growing
2; 500
What are the 4 North American cratons?
Superior (4.3 to 2.6 Ga)
Slave (2.7 Ga)
Churchill (1.83 Ga)
Wyoming (3.0 Ga)
What is continental drift?
The gradual movement of the continents across the Earth’s surface through geological time
What Mesozoic mean?
“Middle life”
The Triassic, Jurassic, and Cretaceous periods were all part of what era?
Mesozoic Era
How long was the era of the dinosaurs (Mesozoic era)?
From 252-66 Ma
This period was the recovery of extinction event; breakup of Pangea; expansion of dinosaurs & gymnosperms/conifers; lasted from 252 to 201 Ma
Triassic Period
This period was more tropical and humid climate; expansion of seas; dinosaurs begin to dominate; first true mammals evolve; lasted from 201 to 145 Ma
Jurassic Period
This period had more expansion of the seas; more seasonality; birds developing; volcanic eruptions affecting atmosphere; many of the dinosaurs in the film ‘Jurassic’ Park are from this period; lasted from 145 to 66 Ma
Cretaceous Period
Alberta and surrounding area mostly formed in the late ______ Period. This period also happens to correspond to the period of dinosaurs
Cretaceous
The different layer of rock are called what?
Beds
The boundaries separating beds are called what?
Contacts
____ period ______ rocks dominate the plains (same type of rocks found near Drumheller)
Cretaceous; sedimentary
Alberta was a ___ at 95 Ma and land by the time of dinosaur extinction __ Ma
sea; 66
What is the K-T (K-Pg) boundary?
The point between the Cretaceous (traditionally abbreviated K) and Tertiary periods (T), now called the Cretaceous-Paleogene (K-Pg)
The K-T boundary has been dated back to ___ Ma when the dinosaurs disappeared
65.5
Who studied the boundary and determined the impactor based on iridium amounts must have been at least 10 km in diameter and would not only destroyed everything locally, but also obscured sunlight from dust globally for years?
Luis & Walter Alvarez (father-son duo)
In what 3 countries have scientists found evidence of the Chicxulub Crater (place of impact)?
Mexico, Ukraine, and India
What era was the Canadian Rockies formed in?
Late Paleozoic Era and uplifted 185 Ma (Western parts) to 55 Ma (eastern foothills)
Mountains make up about how much of the Earth’s terrestrial surface?
30%
What are Hammond’s landforms?
A map depicting the mountain, hills, plains, and tablelands of the world
Majority of Alberta was formed during the ______ era.
Mesozoic
Alberta’s terrain was shaped by ____ geology together with recent ____ history.
older; glacial
The Peace River and Athabasca River both flow into the _______ Delta
Peace-Athabasca
Icefields mountains in Jasper were formed in what period?
Paleozoic
Drumheller rock formations were formed during which 2 eras?
Mesozoic-Cenozoic
The Canadian Shield is made up of ___ bedrock
Precambrian
Northern Alberta rivers flow towards ______ and southern rivers flow towards _____
Artic Ocean; Hudson Bay
