MORAINES OF THE GREAT LAKES REGION

JUST THE FACTS, PLEASE:

NOW THE ANALYSIS:

  1. From the facts presented, circle the terms which best applies to Michigan's moraines.  Briefly explain your choice.
CIRCLE ONE EXPLAIN YOUR CHOICE
SORTED
UNSORTED
  1. There are a few major causes of erosion (e.g. waves, wind, landslides, streams, and glaciers).  Which of these processes commonly leave unsorted deposits?

  1. Explain which of these causes could be responsible for Michigan's moraines.

Therefore, it seems that                is the only erosion agent capable of creating moraines!

  1. The shorelines of the Great Lakes are obviously each a reflection of the shape of the depression which contains the lake.  What similarity exists between the shape of the moraines on the map and the shape of the shorelines of the Great Lakes?

  1. Given this strong relationship between the moraines and the Great Lakes' shorelines, what conclusion can you reach about the likely causes of the moraines and the the depressions now filled by the Great Lakes? 

  1. Evidence suggests continental glaciers completely covered the entire Great Lakes region several times, scratching and gouging across many different kinds of bedrock as they moved.  Why would the Great Lakes depressions be more likely to form on more or less resistant bedrock (pick one and explain)?

  1. The diagrams below illustrate how a continental glacier would probably move into an area which previously had been shaped by stream erosion.

  1. When an ice sheet advances, it often does so as a series of individual finger-shaped masses, called ice lobes.  Ice lobes in our area both gouged out depressions and created moraines at their edges.  The shape and size of each lobe can be estimated by the lake shorelines and the moraines it left behind [see illustration].  One ice lobe on the map moved basically from the West, while the other moved more from the West-Northwest.  Label these two ice lobes on the diagram.

  1. Look at all of your ice motion arrows.  Most people assume that during past ice ages, the ice sheet came directly from the north.  Using the map, explain whether or not this is true.

  1. Find the moraine ridges left by the Lake Erie ice lobe, which are now West-Southwest (WSW) of the western tip of Lake Erie (note boxed area at south-central map margin).  Label each moraine with a number (1 - 4) indicating the order in which they formed (1 = oldest, or first formed).