Re-Os Isotopic Systematics Accompanying the Conversion of Organic-Rich, Pelitic Country Rocks to Hornfels, Magma Contamination and Sulfide Ore-Genesis, Duluth ComplexRipley, EdwardNational Science Foundation (NSF), Directorate for Geosciences, Division of Earth Sciences (ID: 9814204), $113,004USD, 01/01/1999 -- 12/31/2001