lecture 05: pleistocene epoch of quaternary period Flashcards
pleistocene epoch time period
2.58 Ma to 11.7 Ka
milankovitch cycles
‘canon of the earth’s insolation’: characterizes the climates of all the plants
explanation of earth’s long-term climate changes caused by changes in the position of the earth in comparison to the sun
what are the 3 milankovitch orbital cycles
eccentricity, obliquity, precession
beringia
areas free of ice, much of asia, siberia to yukon (some areas up to 1 Ma)
last glacial maximum
ice sheet and glacial coverage peaked
the 2 ice sheets
cordilleran and larentide (divided into keewatin and labrador)
driftless area
glaciers missed one region of the midwest USA leaving an unglacieted region surrounded by glaciated landscapes.
great lakes likely deflected or redirected the glaciers since it’s more sloped and hilly
remaining continental glaciers as of today
antarctic and greenland ice sheets
post-glacial isostatic adjustment
uplift of the land surface following ice melt
north american ice-free corridor
~13.8ka
coast + yukon –> alberta
proglacial lakes
would form at the margins of large glacial lakes created by receding glaciers
misfit streams
forms in the hollow valley of divides or ice dams
glacial lake agassiz
largest proglacial lake in Manitoba and parts of saskatchewan, ontario, n. dakota and minnesota
alberta’s connection to lake aggasiz mega-flood
clearwater to athabasca to arctic ocean
cut the clearwater gorge
sent massive deposits of delta sand down river
potholes
formed from extreme vortexes in the water