Who was an American writer responsible for a dissertation concerning  the towns and districts built near sediment formations around Lake Superior?
Iron Range Iron Range refers collectively or individually to a number of elongated iron-ore mining districts around Lake Superior in the United States and Canada. Despite the word "range," the iron ranges are not mountain chains, but outcrops of Precambrian sedimentary formations containing high percentages of iron. These cherty iron ore deposits are Precambrian in age for the Vermilion Range, while middle Precambrian in age for the Mesabi and Cuyuna Ranges, all in Minnesota. Similarly, the Gogebic Range in Wisconsin and the Marquette Iron Range and Menominee Range in Michigan. Natural ores and concentrates were produced from 1848 until the mid 1950s, when taconites and jaspers were concentrated and pelletized started to become the major source of iron production.
Stephen R. Carpenter Stephen Russell Carpenter is an American lake ecologist who focuses on lake Eutrophication which is the over-enrichment of lake ecosystems leading to toxic blooms of micro-organisms and fish kills. "Eutrophication is a significant environmental problem that can impact humans on a recreational, economic, and even public health level,” says Carpenter, “and it's likely to intensify in the coming decades due to increases in human population, demand for more food, land conversion, and fertilizer use."