Our changing continent
By: [from material supplied by John S. Schlee]
Contributors: Schlee, John Stevens, 1928-.
Series: USGS : INF ; 67-22(R.7)
Publisher: Dept. of the Interior, Geological Survey : for sale by the Supt. of Docs., U.S. Govt. Print. Off.
Published: 1975
Place of publication: [Washington]
Language: eng
Number of pages: 16
Subjects: Physical geography -- North America.; Continents.; Geology -- North America.