Overview
Geology 1203 Earth History
Assignment – Glacial Landscapes
There have been many ice ages over the four billion year history of the Earth, but most people tend to think of the most recent one whenever the subject arises.
While we are not sure exactly when ice developed over the Maritimes it was at least 200,000 years ago. In the last 75 thousand years glaciers advanced and retreated at least four times. Only 20,000 years ago the Maritime Provinces were still covered by ice over a kilometre thick.The direction the ice flowed during advance and retreat are preserved on rock outcrops as elongate scratches called striae (or striations) and drumlins.
So the history of the last glaciation is a story of repeated advance and retreat of ice. During cool periods the ice sheets grow and advance. Water is cycled into ice causing a drop in sea level.The growing glacier advances to the edge of the continental shelf. Eventually the ice begins to melt and the glacier starts to retreat. Melting ice causes sea-level to rise. Released from the load of over a kilometre of ice the land rebounds.
In this assignment we will look at some of the glacial features resulting from the last glaciation.
Procedure
Follow the link to the “A Virtual Field Trip of the Landscapes of Nova Scotia” page at the Nova Scotia Department of Natural Resources. (http://novascotia.ca/natr/meb/fieldtrip/start.asp)
Scroll down until you see the following image of Nova Scotia.
You will see three “Vista of the month” locations. Click on the large red dot that the arrow points to and it will take you to a page showing some different features of the Nova Scotia landscape that formed as a result of the last glaciation.
[or you can scroll farther and see the links for the vistas]
Answer the questions on the following pages which are based upon the information for each of these vistas.