GEOG 2RC3 Lecture Notes - Cenozoic, Canadian Shield, Paleozoic

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Published on 16 Apr 2013
School
McMaster University
Department
Geography
Course
GEOG 2RC3
Professor
Page:
of 3
The Physical Environment
Purpose:
To describe Canada’s physical geography
To consider the relationship between Canada’s physical and
human geographies
To examine the nature of environmental issues in Canada
Questions:
Where is Niagara falls?
Where was Niagara falls 10,000 years ago?
Why is the second question necessary?
o Since the end of the last ice age (12,000 ya), Niagara
falls has ‘retreated’ about 8km up the Niagara river
o Since Father Louis Hennepin saw the falls in 1678,
retreat=300m
o Explanation for ‘retreat’/recession… geologic
composition of Niagara escarpment
The physical Environment:
“why is Canada’s physical geography so essential to and
understanding of its regional geography? (Bone, 20122, 31)
Physical landscapes differ in terms of:
o Landforms
o Geology
o Climate
o Vegetation
o Solid
o Hydrology
Definitions:
Physiographic region: an area with distinct surface landform
features (geomorphology) and underlying rock structure
(geology) see figure 2.1 p. 34
Geomorphology: the study of landforms and the process(es)
of their genesis (from Greek root words: geo-earth; and
morpho- form)
Geology 101
Three basic rock types:
o Igneous- rocks formed when minerals crystalize during
the cooling of molten liquids (ex. Granite (heat))
o Sedimentary- rocks formed through the layering of
mineral particles (ex. Limestone (deposition))
o Metamorphic- existing rocks are altered through
heat/pressure (ex. Shale transformed into slate
(heat/pressure))
Landform Processes
Erosional processes: the wearing away of something by a
force
o Water, ice, wind
Depositional processes:
o Water, ice, wind
Challenges- imaging/understanding the ability of these
processes to alter the physical landscape (force and time)
Canada’s Physiographic Regions:
Geological evolution of North America featured three major
developments:
1) Formation of the Shield:
i. Early pre-Cambrian era
ii. 600milllion to 3.5 billion years ago
iii. metamorphic and igneous rocks
iv. core’ if North America
2) Formation of Mountains:
i. Appalachian Uplands- eastern North America;
Paleozoic
ii. Arctic Uplands- north; Paleozoic era
iii. Western Cordillera- west coast; Cenozoic era
o (These periods of ‘orogenesis’ between 250 and 600
mya)
3) Epeiric seas:
i. Shallow, sub-tropical seas covering interior of
North America during Ordovician and Silurian
periods
ii. Deposition of sediments- Interior plains,
Hudson Bay lowlands, and Great Lakes- St.
Lawrence lowlands
Canadian Shield
See page 36-38
Underlies more than half of Canada
Hard, crystalline rocks (metamorphic), mostly granite
Rocks of western Slave Province, NWT, dated to 4.06 bya
Image/identity of Canada- prototypical Canadian landscape
Western Cordillera
See page 38-39
Pacific Ocean- ‘Ring of Fire’ (plate tectonics)
16% of Canada’s landmass
Two parallel systems of mountains
o Rocky Mountains
o Coast Range Mountains
(Separated by intermontane Plateau)
Interior plains
See page 39-40
20% of Canada’s landmass
Sedimentary rocks
Low ‘relief’- difference in elevation between highest and
lowest points in an areabkb
Elevation increase from east to west

Document Summary

To consider the relationship between canada"s physical and human geographies. To examine the nature of environmental issues in canada. Why is canada"s physical geography so essential to and understanding of its regional geography? (bone, 20122, 31) Physical landscapes differ in terms of: landforms, geology, climate, vegetation, solid, hydrology. Physiographic region: an area with distinct surface landform features (geomorphology) and underlying rock structure (geology) see figure 2. 1 p. 34. Geomorphology: the study of landforms and the process(es) of their genesis (from greek root words: geo-earth; and morpho- form) Three basic rock types: igneous- rocks formed when minerals crystalize during the cooling of molten liquids (ex. Granite (heat): sedimentary- rocks formed through the layering of mineral particles (ex. Limestone (deposition): metamorphic- existing rocks are altered through heat/pressure (ex. Erosional processes: the wearing away of something by a force: water, ice, wind. Challenges- imaging/understanding the ability of these processes to alter the physical landscape (force and time)