Native iron bearing intrusions of the Hammers Dal Complex, north-west Disko

Abstract

In the area between Hammers Dal and Gieseckes Dal on north-west Disko (fig. 10) several native iron bearing intrusions have been found over the years (Münther, 1952, 1973; Pedersen, 1975a). Most of these intrusions were formed at shallow depths as volcanic necks of.iron-bearing, highly contaminated intermediate rocks, which probably served as feeders for the lavas of the Niaqússat member ofthe Maligât Formation (Pedersen, 1975a). In addition a series of interconnected subvolcanic intrusions of a very unusual type - the Hammers Dal Complex (Pedersen, 1975a) - were found in 1972 in the south-facing slopes of Hammers Dal extending a few kilometres towards the north-north-wesl (fig. 11 and Plate 2). Nickel and copper-bearing pyrrhotite mineralization was associated with the wall rock of the intrusions and cumu.late zones of native iron were found in the intllJsions themelves. As these were of potential economic interest a detailed investigation of the complex was desirable. [A preliminary description of the Hammer Dal Complex has aiready been given by Ulff-Møller (1975)].