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 emphasis is placed upon the major problems of correlation. A revised map of the region, with cross sections, accompanies the report, bringing up to date a knowledge of the areal geology of the region, which otherwise could be gained only by consulting some 150 maps contained in almost as many separate local reports, many of which are unpublished.

Report issued by the U.S. Bureau of Mines discussing the operation and production of the Ward Sand and Gravel Company in Oxford, Michigan. The methods and costs employed by the company are presented. This report includes tables, and illustrations.

Report issued by the U.S. Bureau of Mines on studies of the known natural gas reserves in central Michigan sandstone deposits. The geology and methods used to estimate the reserves are presented. This report includes tables, illustrations, and maps.

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."

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."