RT Journal Article SR Electronic T1 The paragenesis and derivation of copper and its associates on Lake Superior JF American Journal of Science JO Am J Sci FD American Journal of Science SP 243 OP 258 DO 10.2475/ajs.s3-2.10.243 VO s3-2 IS 10 A1 Raphael Pumpelly YR 1871 UL http://www.ajsonline.org/content/s3-2/10/243.abstract AB