...S. A. Tyler; S. W. Bailey Abstract Glauconite has been identified from 6 localities in the Precambrian Biwabic Fe-formation of the Mesabi range. The appearance in thin section is that of a normal diagenetic alteration. The field occurrence suggests a secondary origin: 1) localization...

... ) Secondary glauconite in the Biwabic iron-formation of Minnesota . Economic Geology , 56 , 1033 – 1044 . Vassileff , L. ( 1993 ) Pre-Late Cretaceous collides in Bulgaria . Review of the Bulgarian Geological Society , 54 , 1 – 19 (in Bulgarian with English abstract). Velde , B...

... that the likely source of the sulfur in the deposits of the Duluth complex was the adjacent, Animikie-aged Biwabic iron formation and Virginia shale (theme 1). Continuing the theme of Ni depletion, Lightfoot et al. (1984) observed that the Insizwa and Tabankulu intrusions, which are part of the Karoo flood...