GEOG 2OC3 Lecture Notes - Lecture 2: Hudson Bay Lowlands, Glacial Landform, Quaternary
23 May 2018
School
Department
Course
Professor
2OC3
Week 2
The Ice Age
Pleistocene
→ Beginning of Quaternary Period (2.5MYA – Present)
→ Humans evolve into anatomically modern forms
→ Most recent glacial episode in the Northern Hemisphere
o Up to 40 degrees N and 3km thick
Orbital Controls on Glaciation
→ Orbital Eccentricity
o Elliptical orbit impacts summer/winter solstices/equinoxes
→ Axial Precession
o Earth’s rotatioal ais shifts slightl due to graitatioal pull of su + oo
→ Axial Tilt (23.5 degrees)
o The angle of tilt between rotational axis and orbital axis
o Reason we have seasons
Glacial Cycles
→ Large glaciers formed at poles over thousands of years
→ 3km thick glaciers covered all of Canada (18KYA – 25KYA)
→ Millions of Lakes created by retreating glaciers
o Great lakes: % of orld’s surface fresh ater
→ Glaciers caused sea level to drop by 120m
→ Glacial landforms result from erosion or deposition by ice/meltwater
o Drumlins: elongated hills formed by the advance of glaciers acting on the
underlying unconsolidated material
o Moraines: ridges or mounds of glacial material deposited close to the ice margin
often associated with uneven topography
o Eskers: winding ridges of stratified sand & gravel frequently kilometers long,
possibly formed from meltwater running through glacial waters
o Retreat of glaciers
→ Northern Canada contains continuous (always frozen) or discontinuous (sometimes
frozen) permafrost
find more resources at oneclass.com
find more resources at oneclass.com
2OC3
Week 2
Paleogeography
Paleogeomorphology of Canada
→ Earth is 4.5 BYA vs North American landmass is 66 MYA
→ Hadean Period: Earth is a fiery ball of lava
o Canadian Shield formed
→ Supercontinents: Rodinia and Pangaea
→ Precambrian: Canadian Shield
→ Paleozoic: Appalachian + Uplands + Arctic Lands
→ Mesozoic: Interior Plains
→ Cenozoic: Cordillera
→ Quaternary: Great Lakes/ St Lawrence Lowlands
→ Pleistocene: Hudson Bay Lowlands
Mountain Belts (Orogonies)
→ Formed by convergent stress and strain
→ Two tectonic plates squeeze together rock is piled in between forming mountains
→ Canada contains 3 principle mountain chains:
o Rocky Mountains to the West
o Innutian Mountains to the North
o Appalachian Mountains to the East
Epeiric Seas
→ Inland sea caused by high sea levels
→ Leads to limestone caps of lowlands (Alberta Badlands + Niagara Escarpment)
Ancient Animals
→ Woolly Mammoths
→ Sabre-toothed Cats
→ Glyptodons
→ Dinosaurs
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Beginning of quaternary period (2. 5mya present) Most recent glacial episode in the northern hemisphere: up to 40 degrees n and 3km thick. Orbital eccentricity: elliptical orbit impacts summer/winter solstices/equinoxes. Axial tilt (23. 5 degrees: earth"s rotatio(cid:374)al a(cid:454)is shifts slightl(cid:455) due to gra(cid:448)itatio(cid:374)al pull of su(cid:374) + (cid:373)oo(cid:374, the angle of tilt between rotational axis and orbital axis, reason we have seasons. Large glaciers formed at poles over thousands of years. 3km thick glaciers covered all of canada (18kya 25kya) Millions of lakes created by retreating glaciers: great lakes: (cid:1006)(cid:1005)% of (cid:449)orld"s surface fresh (cid:449)ater. Glaciers caused sea level to drop by 120m. Northern canada contains continuous (always frozen) or discontinuous (sometimes frozen) permafrost. Earth is 4. 5 bya vs north american landmass is 66 mya. Hadean period: earth is a fiery ball of lava: canadian shield formed. Paleozoic: appalachian + uplands + arctic lands. Two tectonic plates squeeze together rock is piled in between forming mountains.
