Report of the State Board of Geological Survey for the Years 1891 and 1892: To which are Appended Exhibits Setting Forth the Expenses of the Survey from Its Inception to November 22, 1892, Exclusive of the Cost of Publication. Also the Reports of Dr. Carl Rominger for the Years 1881-2 and 1882-3; of Mr. Charles E. Wright for the Years 1885-8; of Dr. M.E. Wadsworth for the Years 1889, 1890, 1891, 1892, Made to the State Board of Geological Survey for the Years Named: Also a Provisional Report by Dr. M.E. Wadsworth, State Geologist, Upon the Geology of the Iron, Gold and Copper Districts of Michigan ...