Surficial geology

National Atlas of the United States of America
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Abstract

Surficial materials are those at or near the Earth's surface. They constitute, by far, the largest and most used part of the ground around us. Areas not covered by surficial deposits--bare bedrock--form probably less than 5 percent of our land surface.

Most surficial deposits are composed of poorly consolidated clay, silt, sand, or gravel-sized particles that are produced chiefly by erosion and are transported by and finally deposited by water, wind, or ice, but are also partly produced by the in-situ weathering of bedrock. The major genetic categories are shown on the map by various colors; the principal compositional types in each category are indicated by patterns. Colors, patterns, and letter symbols are given in the explanation which follows this summary description.

Surficial deposits have characteristics important to our environment--water-bearing properties, mineral resources, and suitability as a natural foundation for buildings. They are also susceptible to flooding, erosion, ground subsidence, land slides, and earthquakes.

Study Area

Publication type Report
Publication Subtype USGS Unnumbered Series
Title Surficial geology
Series title National Atlas of the United States of America
DOI 10.3133/70211058
Year Published 1984
Language English
Publisher U.S. Geological Survey
Description HTML Document
Country United States
Projection Albers Equal Area Projection
Scale 7500000
Google Analytic Metrics Metrics page
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