Geology of volcanic rocks in the south half of the Ishpeming greenstone belt, Michigan Ishpeming greenstone belt, Michigan Volcanic rocks, south half Ispheming greenstone belt, Michigan Bornhorst, Theodore J. creator author. Johnson, R. C. (Rodney C.) author. Geological Survey (U.S.) issuing body. text bibliography dcu 1993 monographic eng remote 1 online resource (iii, 13 pages) : illustrations, maps. by Theodore J. Bornhorst and Rodney C. Johnson. Title from title screen (viewed May 17, 2016). Includes bibliographical references (page 13). n-us-mi Volcanic ash, tuff, etc Michigan Geology, Stratigraphic Archaean Geology Michigan Archaean Geologic Period Geology Geology, Stratigraphic Volcanic ash, tuff, etc Michigan From 2 to 5 billion years ago fast I 19.3:1904-P I 19.3:1904-P Geology of volcanic rocks in the south half of the Ishpeming greenstone belt, Michigan Bornhorst, Theodore J. (DLC) 92027841 (OCoLC)26404169 Contributions to Precambrian geology of Lake Superior region ; ch. P U.S. Geological Survey bulletin ; 1904-P https://purl.fdlp.gov/GPO/gpo68192 OCLCE 160208 20211120174143.0 in00003797770 eng