Search Results

open access

Pre-Cambrian Rocks of the Lake Superior Region: A Review of Newly Discovered Geologic Features, with a Revised Geologic Map

Description: From abstract: Detailed knowledge of the geology of the pre-Cambrian rocks of the Lake Superior region has been greatly augmented since the publication of Monograph 52 by the United States Geological Survey in 1911. The authors have attempted in the present report to assemble as much of this new information as possible, and to give the reader a birdseye view of the geology as seen in the light of all studies made there up to the present time. Detailed descriptions are not presented, and the emp… more
Date: 1935
Creator: Leith, C. K.; Lund, Richard Jacob & Leith, Andrew
open access

Microscopic Structure and Concentratability of the Important Iron Ores of the United States

Description: Outline of Problem: "This paper covers a survey of 19 ores collected from seven of the more important iron-ore districts of the United States and is a contribution by the ore-dressing section of the United States Bureau of Mines to general research program on iron and steel being conducted by the Bureau."
Date: 1936
Creator: Cooke, S. R. B.
open access

Copper Mining in North America

Description: From introduction: "In this paper are assembled and summarized many subjects relating to the copper industry in North America. Production of mines and districts, history of the industry in North America. Production of mines and districts, history of the industry, geology, of the principal deposits, and mining methods and costs are discussed."
Date: 1938
Creator: Gardner, E. D.; Johnson, C. H. & Butler, B. S.
Back to Top of Screen