Question: Who was an American writer responsible for a dissertation concerning  the towns and districts built near sediment formations around Lake Superior?
Sentence (from "Midcontinent Rift System"): The Midcontinent Rift System (MRS) or Keweenawan Rift is a 2000 km long geological rift in the center of the North American continent and south-central part of the North American plate.
Relevant evidence: No