The area is accessible by foot and vehicle with altitudes between 450m and 1,100m above sea level (asl). In the Kalia area, where the mineralisation has been outlined, peaks of 1,060m occur with the mineralised ridges rising 400-500m from the surrounding lowlands. Slopes are between 10o and 35o with occasional flat crests. Dense tropical vegetation is found in parts of the area.
The Kalia iron mineralisation strike, covering some 40km has been divided into two areas, named Kalia I and Kalia II. This was to facilitate the geological management and planning of the exploration and drilling programmes.
The Kalia I and Kalia II mineralisation’s have been mapped at strike lengths of 19km, and 20km respectively.
Kalia I
The targeted iron ore is situated within the axial zone of a Lower Proterozoic greenstone belt with a west-northwest strike. The greenstone belt is formed by rocks of the Kambui Supergroup. To the south the greenstone belt is bounded by Early Proterozoic gneiss-granites and on the northern boundary biotite granite-gneisses and gneisses are present.
The width of exposures in the surface of rocks of the greenstone association, including ore bodies of magnetite and amphibole-magnetite quartzites, varies from 2 to 4.5 km. The identified strike length of the Kalia I fragment of greenstone within the lease is 19km. The rocks of Kambui Supergroup, enclosing the mineralised zone, are represented by wide spectrum of schists. These include chlorite-amphibole, biotite-amphibole, pyroxene-amphibole, garnet-biotite-amphibole, chlorite and chlorite-talc varieties. Besides schists, amphibolites of different composition are widely developed. On the southern flank of the deposit bands of talc rich assemblages which include, actinolite-talc and chlorite-talc schists occur. These schists contain dissemination of magnetite. The thickness of packets of talc schists ranges from 10-50+ m.
In general, the metamorphism of these rocks corresponds to the greenschist facies.
The mineralised zone of the deposit, consisting of a number of close ore bodies of banded iron (magnetite), amphibole-magnetite schists and talc magnetite schists, extends from northwest to southeast for a distance of 19 km.
Ore bodies and enclosing rocks are characterized by general west-northwest strike (280-315о), and by a sub vertical dip (steeply dipping to south-southwest, 70-80о). Information, obtained from the drilling, as well as from the interpretation of magnetic survey data, indicate the deposit possibly, represents large monocline, complicated by small compressed folds and flexure-like bends.
To the west and northwest of the Kalia I deposit there is a large intrusive massif of mesocratic granites and granodiorites, possibly of the Late Archean age. To the southeast of the Kalia I deposit the greenstone belt and ferruginous quartzites are intruded by large intrusive body of monzogranites of Early Proterozoic age.
Within the Kalia I deposit minor sulphide mineralisation has been identified. Occurrences are narrow and not a focus of current exploration efforts. Sulphide mineralisation is interpreted to be connected with the process of hydrothermal-metasomatic alterations of greenschist formations and BIF. Sulphide mineralisation identified includes pyrrhotite-chalcopyrite and bornite-chalcopyrite-pyrrhotite and pentlandite-chalcopyrite mineral assemblages.
The characteristic feature of the Kalia Iron resource is the wide distribution of a surface weathering crust which forms on all rock types. Within the weathered horizon there is Laterite development principally across the granites and greenschist assemblages, structural eluvial BIF, massive iron oxide ore directly above the BIF horizons, with canga and detrital iron deposits on the flanks of the ridges. Within the weathering crust three types of material are targeted as sources of iron ore;
1. Massive iron oxide of the “haematite / goethite” type
2. Oxidised ores of “canga” type;
3. “Detrital” ore;
The first ore type occurs on ridge crests and plateau areas, and maybe upwards of 60m thick. Canga ores occur on the flanks of the ridge crests and down slope with variable thickness. Detrital ores occur more distal to the ridges where local slope gradients are shallow. Local geomorphology will dictate the thickness of massive iron oxide. In areas of Kalia II, steep escarpments with acute ridge crests have resulted in little or no massive oxide remaining due to erosional processes. In these localities weathered BIF extends to the surface.
Kalia II
The Kalia II Iron deposit is situated within the eastern branch of the Kambui Supergroup greenstone belt. In total, the length of the Kalia II deposit is 20km. The greenstone belt extends past the Kalia Lease boundary and into the Faranah Lease 09/2801.
The geology is similar to that seen at Kalia I, however Kalia II appears more structurally complex. Geological mapping indicates the rocks are intensively faulted and folded. Large bodies of magnetite-haematite and magnetite quartzites (BIF) occur within the axial part of the greenstone belt.
The visible width of outcrop of the greenstone belt in the surface ranges from 2.5 to 2.75 km. An almost vertical dip (from 75о to 90о) is recorded along the whole length of the belt. The target zone consists of inter-bedded Banded Iron Formations (BIF), schists and amphibolites. The thickness of BIF ore bodies ranges from dozens of meters to 200-250m.
The bounding geology represents a mirror image of Kalia I. To the south and southeast of the Kalia II deposit there is a large intrusive massif of mesocratic granites and granodiorites, possibly of the Late Archean age. To the west of the Kalia II deposit the greenstone belt and ferruginous quartzites are intruded by large intrusive body of monzogranites of Early Proterozoic age. To the north, extensive alluvium obscures the geology.
Geomorphologically, the Kalia II deposit is formed by steep escarpments along ridge flanks with narrow ridge crests. These features have resulted in the oxidised layer been stripped by erosion. Localised plateau areas exhibit thin (<10m) developments of iron oxide. On the southern flank of the Kalia II deposit, extensive detrital fans of eroded iron oxide occur. The detrital fans potentially cover over 20km2, detailed mapping and drilling is required to test their potential.
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