Geologic Considerations in Relation to a Materials Survey

In materials surveying, geology should be of maximum benefit, not as a complete informant but as a foundation for reconnaissance, assembly, and cataloging of materials. Geology in essence is a materials survey on a grand scale. Use of this science for engineering purposes involves some primary knowledge of geologic nomenclature, the basic historic approach of geologists, and the use of resources and data published by state, federal, and private agencies over a period of 75 years. Recognition of the need for information on surface conditions as an aid to engineering and allied sciences is emphasized; and in response to this need, a new system of U.S.G.S. mapping is cited and illustrated in which a special map of surficial geology is prepared in conjunction with the traditional bedrock geologic maps. The importance and the difficulty of converting geologic data to engineering uses are considered, and in lieu of a universally satisfactory means for accomplishing this, a few specific conversions are discussed and illustrated. Each is considered separately from the standpoint of possible materials requirements and the application of geologic methods to the location of usable materials