Author Question: You dig into material in a region you know has been glaciated. Explain how you could tell you are ... (Read 71 times)

neverstopbelieb · **on:** Jul 13, 2018

You dig into material in a region you know has been glaciated. Explain how you could tell you are digging into glacial till rather than alluvium.

What will be an ideal response?

Question 2

Explain how and why sea level fluctuated during the Pleistocene.

What will be an ideal response?

pangili4 · **Reply #1 on:** Jul 13, 2018

Answer to Question 1

Answer: Till is composed of unsorted material (rocks, gravel, sands, old soils, etc.) in no particular order with depth. Till will occur over large stretches of landscape. Alluvium is confined to present or former courses of rivers. It will be sorted by grain size. The former is ice-laid while the latter is liquid water laid.

Answer to Question 2

Answer: As continental ice sheets and glaciers advanced their increase in mass was made possible by the capture of snowfall in the hydrologic cycle. Thus, the moisture was unable to flow back to the oceans for a long time. Continued oceanic evaporation meant the lowering of sea level by 130 meters at maximum. This caused the continents to increase somewhat in size and features such as the Bering Land Bridge to exist. The sea level rose as glacial melting exceeded oceanic evaporation.