ABSTRACT
Michigan produced 5,385,849 short tons of copper between the beginning of commercial operations in 1845 and 1969 when several companies ended operations because of labor troubles. Michigan has three iron-ore ranges—the Gogebic, Marquette, and Menominee— which are the roots of middle Precambrian mountains. Petroleum and natural gas are trapped in various ways in sedimentary rock layers. Petroleum, natural gas, coal, gypsum, and salt are found in the sedimentary rocks of the Michigan Basin. The 14,000 ft of sedimentary rocks found on top of the Precambrian formations in Michigan represent a potential for the accumulation of oil and gas. Michigan ranks first in the United States in the production of calcium chloride and gypsum, ranks fourth in cement and sand and gravel, and is a large producer of crushed stone for a variety of purposes. These minerals are found in the sedimentary rocks of the Michigan Basin or in the extensive glacial deposits.
