RT Journal Article SR Electronic T1 Late pre-Cambrian or Lower Cambrian formations in central Virginia JF American Journal of Science JO Am J Sci FD American Journal of Science SP 753 OP 783 DO 10.2475/ajs.248.11.753 VO 248 IS 11 A1 Bloomer, Robert Oliver YR 1950 UL http://www.ajsonline.org/content/248/11/753.abstract AB