GEOLOGIC INTERPRETATION OF GRAVITY AND MAGNETIC DATA OVER THE CENTRAL PART OF THE DULUTH COMPLEX, NORTHEASTERN MINNESOTA

The Duluth Complex, a plutonic component of the midcontinent rift system, has potential for deposits of Cu-Ni sulfides, Ti-V-Cr oxides, and platinum-group elements. Unfiltered and derivative-enhanced gravity and aeromagnetic data were used to interpret the geology of the poorly exposed central part of the Duluth Complex. This study confirms that the complex consists of multiple intrusions of anorthositic, troctolitic, and gabbroic rocks. This configuration is consistent with emplacement by multiple feeders through a highly faulted crust. Several features delineated by this study have significant potential for economic mineralization. -from Author