Establishing a framework for describing the natural world is a necessary first step in all fields of science. Geoscientists face the challenge of describing rocks, which are extraordinarily diverse. Rocks vary in so many ways that talking about them is cumbersome without some sort of standard classification scheme.
Classification systems are artificial and imperfect but nonetheless necessary.
Lake Superior Lake Superior, one of the world's largest lakes, has many of the characteristics of a sea. The current lake level is about 1.5 feet above its historical average of 602 feet, and shoreline erosion is a serious concern for those who live near the lake. In this way too, Lake Superior can act as a laboratory for studying oceanographic phenomena, because global sea level rise is one of the expected effects of greenhouse warming. We will walk out on the large rocks that were brought in from elsewhere along the Lake Superior shore to protect the north end of the Portage Waterway. These wave-washed rocks record a tremendous range of geologic processes and histories.