A PRELIMINARY X-RAY FLUORESCENCE INVESTIGATION OF THE DJEBEL HAD IRON FORMATION (DHIF) OF NORTHEASTERN ALGERIA

From 1865 to 1950, Algerian iron mines produced approximately 77 million tons of iron ore and currently Algeria has 2.9% of the world's iron ore reserves. Several Algerian iron ore deposits have not yet been evaluated in detail for their economic potential. One such deposit is the Djebel Had Iron Formation (DHIF), which is a six to eight meter thick distinct stratiform sedimentary iron deposit. This deposit occurs in the large mining district south of Tebessa in northeastern Algeria and shares stratigraphic, lithological, structural and metallogenic relationships with southwestern Tunisia. For a preliminary analysis, twenty outcrop samples were taken at 1 to 0.5 meter intervals from the host rock and mineralized zones of the DHIF on the north side of Babouche syncline at Kef en Nessour. Mineralization occurs as layers of oolitic iron ore and inter-laminated iron marl within mid-Eocene gypsiferous marls. Scanning electron microscopy and powder X-ray diffraction data indicate that rounded brownish-blackish oolites, 2-10s of mm in diameter, are composed of goethite, limonite, hematite, with traces of magnetite and piemontite. For X-ray fluorescence analysis, samples were analyzed on a Rigaku Supermini 200 wavelength-dispersive x-ray fluorescence spectrometer at the University of Cincinnati. The Supermini 200 analyzes for elements between fluorine and uranium, and reported data are normalized to 100 weight percent. LOI and elements lighter than fluorine were not analyzed. Fe2O3 concentrations varied from 17.17 wt% to 96.85 wt% with a mean concentration of 57.44 wt%. Other metals of interest occurred in detectable quantities and include Cr (n=4 samples, 0.01-0.03 wt%), Zn (n= 7 samples, 0.20 to 0.69 wt%), and As (n=6 samples, 0.01 to 0.04 wt%). These preliminary analyses justify further work to investigate this deposit including work to better understand potential byproduct metals and evaluate potential environmental concerns.