EESA06H3 Lecture Notes - Lecture 11: Terrane, Oceanic Crust, Paleozoic
Introduction to Planet Earth
March 21st, 2016
Lecture 11: Canada’s Geologic Journey: The Last 4.5 Billion Years [Continued] (Part 1)
Chapters 16 and 20
Prof: Good morning. 2 weeks to go. We’re just wrapping up and review the remaining geologic
history of Canada. Have a look at chapter 20 because that’s the summary. Next week, we’ll look
at some environmental issues. Have a look of the rocks on campus.
Breakup of Rodinia (c. 570 million years ago)
- Creation of an independent North America (‘Laurentia’) and the quietest episode of its
long geologic history (quietest phase in North America)
- All the rocks from ‘wall rock’ were form at that time
- Rodinia breaks up and it formed the Iapetus Ocean and you know the story where it
close and it forms the next supercontinent which is Pangea
- Geology doesn’t rhyme but it often repeats itself
- The sedimentary rocks that rest on this shield are what we call ‘carbonates’ in reference
to the minerals like calcium carbonate (limestones)
o Limestones once covered much of the shield but we still find ‘cover rocks’
o Limestones is the most common rock type in Southern Ontario whereas the most
common one in the North is Nice
300 Ma ‘PANGEA’
- Dramatic change as Gondwana collides with Eastern North America which becomes an
active plate margin
- ‘Appalachian Orogeny’
o The closure of the ocean and the creation of Pangea
- Maritime Canada is added (‘Out of Africa’)
o When the Atlantic Ocean opened, it got left behind
- Detrital means broken (made of fragments of other material)
o Lots of mud and sand.
o When the mud solidifies, it becomes shale
- The Appalachian Mountains is the Orogen which resulted in an Orogeny
o Added during the formation of Pangea about 600 million-300 million years ago
Foreland Basins during Pangean Orogenies (Fig. 20.17)
- Isostasy is when the continents are big blocks of wood floating on this small dense
mantle underneath so high mountain gets deeper roots
- We build these mountains by collision and folding
- These basins are called sedimentary basins and we call them foreland basins because
we’re in the fore-front of the mountain
o We cover much of the interior with sedimentary rocks
- In Toronto, we were a part of the Michigan Basin
find more resources at oneclass.com
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Document Summary
Lecture 11: canada"s geologic journey: the last 4. 5 billion years [continued] (part 1) We"re just wrapping up and review the remaining geologic history of canada. Have a look at chapter 20 because that"s the summary. Next week, we"ll look at some environmental issues. Have a look of the rocks on campus. Breakup of rodinia (c. 570 million years ago) Creation of an independent north america ( laurentia") and the quietest episode of its long geologic history (quietest phase in north america) All the rocks from wall rock" were form at that time. Rodinia breaks up and it formed the iapetus ocean and you know the story where it close and it forms the next supercontinent which is pangea. Geology doesn"t rhyme but it often repeats itself. Dramatic change as gondwana collides with eastern north america which becomes an active plate margin. Appalachian orogeny": the closure of the ocean and the creation of pangea.
