GEOG 1290 Lecture Notes - Lecture 9: Wisconsin Glaciation, Continental Crust, Plate Tectonics
Document Summary
Caused by ice sheet deposition (thick deposits of drifts (cid:0) particular landforms) Along river tunnels within glaciers (log sinuous ridge of sediment) e. g, bird"s hill and northern portion of highway 6: outwash plain: Smooth sloping plain of stratified drift: the terminal moraine: till plain: Flat area behind a terminal moraine of unsorted sediment: drumlins: Formed when ice reshapes pre-existing till in groups of drumlins. Marginal/ glacial lakes: melt water accumulate at ice margin blocked by moraines/ delta becomes a kame (flat-topped hill of well higher ground. Glacial deltas form where water enters (cid:0) sorted debris) Max extent of ice took 18,000 yrs ago. Major ice sheet: spread out over surrounding areas. Weight of ice reduced the continental crust. Change in the position of continents (plate tectonic activity) Milankovitch cycles changes in orbital mechanics of earth eccentricityp degree of ellipticity of earth"s orbit.