MINISTRY OF MINERALS

GEOLOGICAL RESEARCH AUTHORITY OF THE SUDAN

ED EL FURSAN BANDED IRON FORMATION (BIF), ITS RELATION WITH KASS MASSIVE SULPHIDES, AND THE REGIONAL HYDROTHERMAL BUDGET, SOUTH DARFUR STATE, SUDAN.

BY: NASRELDIN WADELNOUR YOUSIF EL SAMMANI ELSHEIKH ABDEL RAHMAN MOHMED ABDEL BAGI ELFADIL MOUSTAFA AWAD MOHMED AHMED

Nov.2010

1 ED EL FURSAN BANDED IRON FORMATION (BIF), ITS RELATION WITH KASS MASSIVE SULPHIDES, AND THE REGIONAL HYDROTHERMAL BUDGET, SOUTH DARFUR STATE, SUDAN. Mohmed Ali, NW., El Sammani, Y., Abdel Rahman, EM., Abdel Bagi, M, El Faki, EM. GRAS, P.O.BOX, 410 Khartoum, Sudan.

Abstract

The paper discusses an origin of a variety of Banded iron formation (BIF) which mainly defined as Algoma and Lake Superior types. This one here at Ed El Fursan, at south Darfur state differs from the above mentioned categories in nature. This BIF is from geological and chemical stand points is hydrothermal, and emplaced episodically in quartzites, the host rocks. The area is generally characterized by high grade metamorphism of probably Proterozoic age. The mineralization perhaps intruded during green schist facies as favorable conditions and suffered amphibolite degree of metamorphism with the rest of the succession. Other discussed metallogeny is the Leona sulphides that are very rich in lead and associated silver (90% Pb, 2500ppm Ag) which generally considered as precious ore. The hydrothermal budget and comparison revealed that the BIF and probably SEDEX massive sulphides are probably formed from the same magma and its successive hydrothermal solutions in multiple phases that characterize the metallogeny of the area along definite structural lineaments. The comparison also between the sulphides of south Darfur and those of north Kordofan refer to the same magma chamber and its evolutionary hydrothermal phases which may hint to its immense size and impact in the two large regions. The artisanal gold is probably one of the mineral paragenesis of these processes. Finally, the magma evolution state, despite the large time span between lower Proterozoic (gneissic cratonic terrane, current study) and upper Proterozoic (Pan African, some parts of Haya terrane), similarity is preserved in mineralizations genetic model as a result of multiple phase of hydrothermalism. The process is highly controlled by metamorphism, deformation, initial conditions, and mechanism of repetition. The process might started early since Archaean wherever encountered.

2 1. INTRODUCTION This report has been accomplished in the occasion of the visit of south Darfur state and its capital Nyala city. It is an attempt to reopen GRAS office for the increasing demand first to provide regional governments with financial resources through fees of exploitation of building material. Moreover to handle the augmenting role of the new structure of GRAS as a ministry of minerals contribution in the general economy of the state through the other minerals mining leases for the immense mineral resources exists in the area. During the mission there were discoveries in the process. First Ed El Fursan Banded Iron Formation (BIF). The second is the Kass massive sulphides at Leona village. The first has been compared with the other BIF ore deposits regionally and internationally. It is found that its characterized by very particular geological features beside its common characteristics with the other BIF else where. It is characterized by intrusive nature in a sedimentary host with multiphase emplacement patterns. In this concern, the problem of the host rock is going to be discussed. Massive sulphides were discovered at Um Leona village about 15 km from Kass city to the direction of Nyala city. The ore extend discontinuously with the particularly significant properties for long distance. The first is that the ore is very rich in Pb and in turn Ag as its usually used to be hosted in galena. Similar to this ore is the one found at Abu Zaema NW Sodari, north Kordofan province a comparison will discussed based on chemical and geological grounds. This has both economic and geological significances, as this ore contains the values of precious metals mentioned above. The gold artisanal work is mainly focused on these mineralizations paragenesis and their associated quartz veins. The geological is that the ore paragenesis successfully revealed the nature of metallogeny in the region (Mohmed Ali et al. 2010 a, B, and C) after through correlations. The same thing could be mentioned about the nature of metallogeny in South Darfur Province. The mineralizations relations of Hofrat En Nahas, Mazroub has been discussed before (Abdel Rahman et al. 2006, Mohmed Ali et al 2010) in tectonic and chemical properties respectively. The final result is that the metallogeny question would be answered in the area of north Kordofan and south Darfur or the two regions in general. Besides, these mineralizations are very rich in base and precious metals that would efficiently contribute to the economies of these areas. The problem of BIF could be discussed in the framework of hydrothermal activities cast both regions as the geological evaluation so far succeeded to do so. That by it self could be considered as a case study contribution in the dissection of the enigmatic and wider dispute about BIF genesis and characteristics. Other problem is that the quartzite and the associated remobilisate quartz veins that are suspected

3 to be auriferous are crushed and used as a construction material aggregate by construction companies for a decade, the thing that can bear irreversible damage for these nonrenewable resources. Such a problem has been discussed with other ore bodies in other locations. It is high time to issue a hazard about this problem, especially with the new current ministry structure. 1.1. LOCATION AND ACCESSIBILITY The bodies in question, the Ed El Fursan, other used names, Ed El Kheil and Ed El Haraz, precisely located at coordinates N 11º 47' 09"- E 24º 26' 27", 59km southwest Nyala (Table 1. Fig.A). Accessibility from Khartoum is little difficult with mission convoy vehicles, as the area is very far and remote. Nowadays, GRAS reopened office in Nyala so as to coordinate as much as possible with the local government to cover most of the geological activities including mining. It is most practical to prepare for field mission from the terminal office at Nyala. Other wise Railway line is active to Khartoum and this also considered as an option whenever there is insistence to use available resources. Airway aviation services are also available in regular basis. 1.2. OBJECTIVES OF THE STUDY There are many studies carried out in the area and the neighbouring (North Kordofan Province), this study aimed to correlate geological, structural, metallogeny, and feasibility aspects of the area (south Darfur state) in order to properly evaluate the economic potentiality of the area. Recently, the area witnessed many activities (North Kordofan Province) of most importance is the artisanal mining as the recently established Ministry of Minerals planned to coup with the great explosion of artisanal mining that exposed over a sudden at all the regions of the country. The ministry every day has to encounter developments and repercussions of the processes either in a positive or negative impact. The areas under evaluation in adjacent north Kordofan province include the Mazroub, Tinna quartz veins, comparison between Tinna (quartz veins) and Mazroub (sulphides) mineralizations similarities. Another study includes quartz veins discovered more to the west around Sodari (Al Firga), others are samples collected from Abu Zaema massive sulphides. The purpose of this report is to continue this trend of studies more to the west to the neighbouring south Darfur province. The research prospect precisely includes sulphides that are discovered at Leona village and extend for long distance as a belt. From geological point of view these sulphides are similar to those discovered at Abu Zaema. Similarities imply general petrology, metamorphism and chemical affinities as its going to be discussed. The dominance of galena as the main mineral ore 90% concentration, this huge Pb concentration contains around 4000ppm Ag. This by itself is a fortune and mineral wealth that deserve proper

4 evaluation. Another discovered commodity is the Banded Iron Formation (BIF). It was found 60km southwest to Nyala city. This kind of iron contains magnetite which is a very important industrial mineral. This iron is probably of hydrothermal origin as its going to be discussed in controversy with the generally known BIF. Other main similar mineralizations in the area are Kutum lead zinc at the north and Hofrat En Nehas few hundreds of Kilometers form Ed El Fursan area where the BIF iron was discovered. The correlation of hydrothermal budget between the two regions might lead to strong similarities. Based on that the metallogeny of north Kordofan and at least north and south Darfur states should be treated as extensions or one geological unit or Metallogenic Province. 2. GEOLOGY 2. 1. GENERAL GEOLOGY In the literature there are two types of BIF ore deposits: 1. Algoma type BIF, which is composed of finely layered intercalation of silica and iron, generally hematite and/or magnetite bearing but the individual layers lack continuity. 2. Lake Superior type BIF usually deposited in shallow waters, continental shelves or ancient sedimentary basins. Algoma type is of a much wider time span. BIF is generally defined as a chemical precipitate of sedimentary rocks, or have more than 15% sedimentary iron. Some of them are arguably belong to Archaean supracrustal rocks, generally range about 1.1-2.3 Ga. Klein (2005) made a comparative study in their types all around the world, including their age, geological setting, mineralogy, metamorphism, geochemistry, and origins. Their host rocks are of various types; shales, cherts, and quartzites. Some bands are iron rich whereas others are poor, some are 600-800 m.a. old, actually in a long time span during the Precambrian. In some of their characteristics they are similar to the oolitic iron as the cyanobacteria played a major in their precipitation. Oxygen was released by cyanobacteria and combined with the dissolved iron to form insoluble iron oxides that precipitated directly. Composition generally ranges between 20-40% (Britton, 2007). Recent world wide recognition for their long debated origins settled on composition that formed of magnetite and/or hematite-carbonate and talc rich mineralization (Dalestra et al. 2004). An example of Archaean green stone belt is given (Angerer et al. 2010), that composed mainly of hematite and goethite and linked its emplacement with deformational phases. A BIF hosted high scale iron deposit in the Archaean of Koolyanobbing green stone belt (western Australia) that is synergetic and structurally controlled and with weathering related magnetite, hematite and goethite rich iron ore.

5 2.2.GEOLOGY OF MINERALIZATION 2.2.1. THE BANDED IRON FORMATION (BIF) The geology of the area is very rich with mineral resources, in the area there are many obstacles that inhibit the proper usage of mineral resources among these problems, the usage of quartz veins associated with quartzites as crushing aggregate for road construction for a long period of time. These quartz veins and quartzite aggregate might contain gold in commercial amounts. Marbles are burned and used as polishing lime in a primitive usage and that might have been continued for decades. It is also used to protect the ground and sides of roads which are newly constructed, sometimes it was drifted by rain water. It is generally known that these resources are nonrenewable and careful use is indispensable to protect this treasure. In our view, all these misuses are happened as a result of ignoring the geologist role as the proper guardian of this mineral wealth. So before using all rock types specially in commercial amounts in various purposes, a geologist have to be consulted as a must. A decree issued by the authorities in this concern is imperative (Plate 2 and 3). Alternatives of quartz veins aggregates is the other rocks of the basement that exist in huge amounts like, ortho and paragneisses, and amphibolites. Post tectonic granites are also wide spread in the area. There was a thinking that it might be used for cutting ornament material and decoration stone instead of been used as also aggregate. All these projects are proposed for the local governments for the perfect utilization of these resources. Local governments are in vital need of finance for their own operations aside from central government budget. The geology in the area is characterized dominantly by low relief outcrops and subdued terranes that mainly represent a rock assemblage of the amphibolite facies degree of metamorphism. The rocks are mainly ortho and paragneisses, quartzite that is wide spread in the area. Marble is also found and used as quarries by the locals by burning and selling in the market (Plate. 3). An advanced thinking is to construct cement manufactories to contribute in the development of the area. As the geology in the three Darfur states is almost similar, its quite expected to encounter enough marble quantities that can satisfy the local needs. Cement prices in these areas is very expensive that would impede local development. Quartzites, the main theme of the study as a host rock for BIF is having many geological characteristics that are observed on most of the visited quartzites. An example taken by the author, the quartzites of Abu Tulu, they have been sampled and analyzed. Unfortunately, they were not mineralized by gold but that does not mean that all of them are barren. Second and third generations of silica remobilisate are intersecting these quartzites as a result of deformation and metamorphism (Plate 4).

6 Definitely they imprint all deformational and metamorphic phases in the area (Plate 4). The same could be mentioned for the quartzites of Ed El Fursan, as they are fractured according to the metamorphic and deformational phases (Plates 4, 5, and 6). The Banded Iron Formation (BIF) is emplaced along synkenamatic fractures. They are tectonically controlled along, first the primary sedimentary structures as zones of weaknesses, second vie hydraulic fractures. Most probably they were not emplaced in the cratonized phase as its quite possible they were intruded in the most dynamic and favorable green schist facies (Mohmed Ali et 2010 A and B). Their mechanism of formation is as follows; first hydraulic fracturing and then hydrothermal solutions are emplaced as fractures filling at the green schist facies and conditions, making use of hydraulic fracturing. Quartz veins that are found intersecting quartzites follow the same mechanism (Plates 5, 6, and 7). Sometimes, they were very concentrated and all of the levels along the strike are mineralized. The deformation has very strong impact on these rocks. It is known that silica is among the most mobile minerals at low pressure and temperature. It is used to be dissolved under these conditions with the implication of metamorphic water and intrude their host in number of phases corresponds to the number of metamorphic and deformational phases. The most favorable axis is along the strike, parallel to lineations and tectonically enhanced silica emplacement and the most disturbing for mineralization. The much the quartz veins intrusion, the low is the ore concentration. So deformation and quartz veining have negative impact on ore concentration and vice versa (Plate 7and 8). The quartz veins could increase gradually at the expense of the ore until it form a network or boxwork that might suite gold rather than iron mineralization. The final picture is a domination of quartz vein and gradual vanishing of the ore until the ore is disseminated in island-like manner in a sea of silica or restite wholly formed silica. Also the final shape is formed of iron enclosed as xenoliths in quartz matrix or ground mass (Plates 9, 10, 11, 12, and 13 in the report). The multiple emplacement of iron rich solutions is also could be observed in the field where quartz veins, veinlets and congregates could be found as xenoliths in iron ground mass. Veinlets and veins are found with discontinuities that indicate that they were attacked by hydrothermal iron rich solutions (Plates 14 and 15 in the report). The iron rich hydrothermal solutions for instances are associated with brecciation and disturb the whole succession (Plate 16 in the report). The general structure of the quartzite host is that it is extending for along one kilometer, often broken and in mostly disturbed by quartz veins that came later and emplaced mostly along lineations parallel to the general strike of the rocks (Plates 17 and 18 in the report) and for many

7 instances all around the succession indiscriminately in a boxwork. The thickness, sometimes reach 3 meters (Plate 19 in the report). Few views illustrate that the BIF is mainly a fracture filling rather than of a sedimentary derivation (Plate 20 in the report) due to the examples mentioned above. The same sense could be observed in several other locations, the boundary between the ferruginous and siliceous layers is distinctly abrupt (plate 21, 22 in the report). Based on all these field and geological evidences, beside chemical evidences (will be discussed later) might contribute immensely to the assumption that at least partially among many other origins, a hydrothermal derivation for the BIF should be highly considered or put into effect. 2.2.2. UM LOANA MASSIVE SULPHIDES The samples of Umm Leona massive sulphides (Plates 13, 14) were brought from a village (Um Leona), located 14km east of Kass city. The sample is similar to that sulphides brought from Abu Zaema around Sodari. The similarities appear in mineral paragenesis, common host rock, degree of metamorphism, and chemical composition. That might implicate them in similar genetic model. Such an approach has a very great implication on the geology of the region to render it similar to south Kordofan region in many aspects. A comparison based on chemical grounds will be discussed later as similar geology was referred to. The host rock in the two ores is basement gneisses in the amphibolite degree of metamorphism in the cratonized phase. Most probably they are both SEDEX or VMS as the protolith could be of volcaniclastic derivation or paragneisses of the pelitic material. The Um Leona massive sulphides that are highly enriched in galena and associated silver should be tracked and evaluated for proper prospecting and exploitation. 3. MINERALIZATION 3.1. GEOCHEMISTRY OF MINERALIZATION 3.1.1. BIF GEOCHEMISTRY AND STATISTICAL DATA It appears that Edel El Fursan BIF contains gold, two samples out of twelve, show gold 0.02 and 0.01 g/t Au, with average value of 0.0025 g/t. Ag is also promising, with average grade 5.8 g/t , min. value 1.3, and max. value 27.3 g/t Ag. These precious elements should be targeted by detailed exploration. The ore also show minor amounts of Mn, Zn, Cu, and Co, although potential. Fe is the important component with average grade of 12%, min. value of 5.85% and max. value of 22.04%. The above mentioned Au, Ag, and Fe should be followed by detailed exploration program. 3.1.2. LEONA MASSIVE SULPHIDES GEOCHEMITRY AND STATISTICS These sulphides appear similar to those of Abu Zaema around Sodari in many aspects. First, the host rock as gneisses, and as they are

8 both coarse grained for they sustained high degree of metamorphism as recrystallization, sample appearance, the very high concentration of Pb, Ag, and Cu. The two provinces are located to each other and perhaps with the same geology. It contains 93% Pb average grade, 86.4 min. value, and 98.7% max. value. These values are among the highest in the world. Usually, high Pb is associated with high Ag, 1981 g/t average grade, 1496 min value, 2750 max. value. Also these values are considered very high, and such an ore is very close to exploitation for the chemical nature is very feasible at utmost poor conditions of feasibility aspects, although, it was discussed and proved positive. Based on that the ore is considered as Bonanza type precious metals. Moreover, as gold is not currently recorded at these samples, however, its highly potential as its found in similar compositions. In general the region is most potential for Au, Ag, Pb, and Cu, whereas other basemetals are highly expected as they are usual mineral paragenesis with the above mentioned mineral categories. Of less importance in this ore is Cu as 261 ppm average grade, 210 ppm min. value, and 327 ppm max. value. The difference between the sulphides of Leona (southwest Darfur) and those of Abu Zaema (north Kordofan) is that in Abu Zaema is richer in Au, Ag, and Cu, whereas Pb in Leona sulphides is very rich (98.7%). The mineral paragenesis in general is the same in both facies. 3.2.THE EXPLANATION OF HIGH GRADE LEAD (Pb) Replacement metasomatism is the main reaction type that controls the evolution of both host rocks and mineral groups. Pb in general is an indicator of the advanced stage of magma evolution in acidic composition that dominated by ortho and paragneisses. The same could be mentioned for massive sulphides. In northern Darfur, there is Kutum Pb-Zn sulphide mineralization associated with evoluted granitic magma, so granitic hydrothermal source contribution is not fully excluded in the genetic model of the VMS origin proposed. The 98.7% Pb is rationalized via the mechanism of the very advanced stage of Pb replacement of the other trace elements until finally replaced the sulphur of the galena mineral. The result is the psuedomorphic texture of the galena that is very highly replaced by free Pb. The factor multiplied to the free Pb far exceeded the typical 100% value of the ideal mineral galena, so it could only be explained by the above mentioned phenomena. 3.4. THE CONCEPT OF METALLOGENIC PROVINCE The concept of metallogenic province is applicable to the area of north Kordofan and most of Darfur region for the following reasons: Mineral occurrences are Mazroub gossans, the artisanal quartz veins that are found in Tinna north of Mazroub in the east, to Sodari and Um Badir quartz veins in the west. The VMS various types; Mazroub gossans, Abu Zaema sulphides, all at north Kordofan state. At Darfur, there is Hofrat

9 En Nahas (south west Darfur), Leona massive sulphides (east Nyala), Kutum sulphides (east Darfur), BIF of igneous origin (southwest Nyala). So far, the studies confirmed that the magmatic budget as source is firstly is very huge one and the cause of mineral deposit evolution for ore bodies of both regions. It is quite expected, beside the current artisanal mining, the area would soon witness extensive exploration and prospection works. 3.5. CHEMICAL CORRELATION SIGNIFICANCE The correlation basis is summarized on the few steps. First to choose a pair of elements and to draw XY correlation Path. Elements that appear with extremely positive correlations represent the same close mineral paragenesis in the ore. Minerals with extreme negative signals or negatively correlated represent replacement reactions and indicate that one mineral grew at the expense of the other. That would also refer to that they are not of the same mineral paragenesis. Probably succeeding pulse of hydrothermal enrichment or other phase of ore accumulation. That would also support multiple phase hydrothermal enrichment notions as a genetic model for the mineralization in question close with other supporting evidences. The similarities of general diagrams of correlation might refer to the mechanism of many operating and controlling factors. In detail, those which indicate chemical equilibrium and reaction conditions, controlling condition like PTX, and growing path beside the above mentioned characteristics. Very detailed discussion on these correlations might give a full or partial idea about the real mineral paragenesis of the ore emplacement in multiple emplacement pulses or phases. All these signals similarities for the rest of elements diagrams for the same ore deposit or in comparison with other suspected mineralizations might indicate the same source and the slight variation indicate particular differences of mostly in time and space. The most important of all is that these diagrams similarities might indicate same genetic models and definitely would solve the problems of mineralizations geological settings if properly interpreted. 3.6. GEOCHEMICAL CORRELATION OF BOTH ORE BODIES It was assumed that the genetic model of both mineralization, BIF and Leona sulphides are formed from the same magma or succeeding multiple hydrothermal phases while same chemical signals are observed. Based on the above mentioned technique that can reveal chemical aspects of both processes the following could be observed: Ag/Mn in BIF is negatively correlated and the same thing could be mentioned at Leona sulphides (Fig. 1, 2). Ag/Fe of BIF is also negatively correlated and the same could be mentioned about Leona sulphides (Fig. 3 and 4). The elements regrouping as observed could indicate double reaction impetus or multiple phase injection that usually characterize massive sulphides emplacement. Negative correlation as mentioned

11 before refer to different mineral phases and one mineral grew at expense of the other; Ag grew at expense of Fe and Mn which could represent primary phase, and came later in the chronology of hydrothermal events. Zn/Ag is slightly positively correlated in BIF and Leona sulphides and accordingly that might refer to that they represent the same mineral phase (Fig. 5 and 6) as they coexist in gently positive slope. Fe/Zn is negatively correlated as different phases in both BIF and Leona sulphides as obviously they replace each other (Fig. 7 and 8). It is quite possible that Mn and Fe are the primary phases and in later phases they were replaced by basemetals. Cu/Fe also is negatively correlated and also Cu replaced Fe in Both BIF and Leona sulphides as mentioned before (Fig. 9 and 10). Fe and Mn are positively correlated and probably they represent the primary phase or hydrothermal pulse that emplaced the BIF. (Fig. 11 and 12 in the report). Cu/Mn are also negatively correlated and the same role is applied that Cu was the later phase that grew at the expense of Mn and Fe (Fig. 13 and 14 in the report). Comparison between sulphides is much easier as they form similar evolutionary path and entity from thermodynamic point of view. They could have been formed synchronously or multiply injected for they bear similar aspects and imprints. Cu/Pb in Leona sulphides and Sodari sulphides are slightly positively correlated and probably represent the same mineral phase (Fig. 15 and 16 in the report). Cu/Zn is also positively correlated at both Leona and Sodari sulphides and they are of the same generation (Fig. 12 and 13). It is very important to notice replacement reactions are expressed in textures in terms of minerals like pyrite, chalcopyrite, sphalerite, and galena. To conclude, it appears that the massive sulphides were probably formed and evoluted from the same magma chamber or the driven associated hydrothermal solutions and as these ore bodies are large distance apart, which would refer to that the source magma or hydrothermal pool is huge enough to form such an ore. Their chemistry is similar, their evolution path, and mineral paragenesis are also similar. BIF was known to be of chemical sediments derivation due to its host quartzite origin, however, its quite possible it has encountered a hydrothermal intrusion that dominated the area. From chemical and geological point of view, the associated BIF is of hydrothermal origin and formed by the same magma and hydrothermal system dominated the area and formed the various types of sulphides. 4. CONCLUSIONS AND RECOMMENDATIONS 1. After thorough investigation that include various geological aspects and geochemistry, BIF and Leona sulphides are formed by the same magma and hydrothermal system that dominated the area from Sodari (Abu Zaema) massive sulphides.

11 2. These areas that covered important parts of Kordofan and Darfur Provinces, shows similar mineralization Metallogenic Province, that include quartz veins (intensive silicification) and sulphides. 3. The area encountered new source of BIF that formed via hyrothermalism that covered the huge area of Darfur and Kordofan provinces. 4. Other studies like textures, isotopic age, fluid inclusions, geochronology, might reveal kinetics of the different ores. 5. From economic point of view and the various economic feasibility aspects, these ores are very a very profitable operation important and profitably amenable to mining. 6. The high values of Au, Pb, Ag, and Cu make it a very profitable mining operation after thorough mineral exploration and prospecting are conducted. 7. These mineralizations are variably affected by cratonization processes as they were mostly emplaced in the green schist facies conditions, and that include textures after recrystallization for they become coarse grained, and mineral paragenesis of the associated minerals and host rocks after deformation and metamorphism. 8. It is imperative to issue a hazard towards unorganized usage of mineral resources as aggregates that might destroy such a non renewable resources. REFERENCES Abdel Rahman, E.M., El Mahi, J. (2006) A new discovery of base metals mineralization in north Kordofan, Sudan: implication for Trans- Shield mineralized Corridor. The 9th. Arab conference for mineral resources. Jeddah. Saudi Arabia.p.33. Angerer, T., Hagemann, G. (2010) The BIF hosted high scale iron ore deposits in the Archaean Koolyanobbing green stone belt, western Australia: structural control synorogenic and weathering related magnetite, hematite, and goethite rich iron ore. Economic geology, 105, 5, p. 917-945. Britton, A. (2007) Banded iron formation. GPH2/Arizona Univ. (eds). Dalestra, H., Guedes, s. (2004) Giant hydrothermal hematite deposit with Fe-Mg metasomatism: a comparison of the Carajas, Hamersley, and other iron ores. Economic geology, V 99, 8, 1793-1800. Klein, C. (2005) Some Precambrian banded Iron formation (BIF) from around the world. Their age, geological setting, mineralogy, metamorphism, geochemistry, and origins. Geoscience world. 1473-99. Mohmed Ali, N.W., Obied, A., Abdel Rahman, E.M., Ibrahim, A., Sulieman, M. (2010) Episodic hydrothermal injection of manganese rich mineralization at Haya Terrane, Alaikalib, Abu Samr, and Sinkat Hamot. 11th. Arab mining conference, Tripoli, People.Rep. Libya.

12 Mohmed Ali, NW. (2009) Episodic hydrothermal injection of manganese rich mineralization at Haya Terrane: Alaikalib, Abu Samr, and Sinkat- Hamot, Red Sea Hills Province, Sudan. Gras. Unpubl. Report. Mohmed Ali, N.W., El Tayeb, H. (2010) Distal and proximal quartz veins in the gossan regions: A similar genetic model-example; Mazroub, Sodari areas, North kordofan State. GRAS unpubl. Report. Mohmed Ali, N.W., El Sammani, Y., Abdel Rahman, E., Ibrahim, A., Sulieman, M., El Tayeb, H. (2010) Distal and proximal quartz veins in the gossan regions: A similar genetic model-example; Mazroub, Sodari areas, North kordofan State. 3rd. Mining economies conference, Cairo, Egypt. Mohmed Ali, N.W., Obied, A., Abdel Rahman, E.M., Ibrahim, A., Sulieman, M. (2010) Structure and metallogeny of the Mazroub gossans. North Kordofan State. 2nd. Mining Economics Conference, Cairo, Egypt Mohmed Ali, N.W. (2006) The geology and mineralization of the Abu Tulu iron ore deposit. The 9th. Arab conference for mineral resources. Jeddah. Saudi Arabia. Mohmed Ali, NW., El Nitiefa, MA., Moustafa, E., Bannaga, MA., (2010) Metallogeny of the cratonized terrane adjacent to green stone belts, examples; Alaikalib, Mazroub, Sodari and Um Badir. GRAS unpubl.Report. Mohmed Ali, El Sammani, y., Abdel Rahman, EM., Ibrahim, A., Sulieman, M. (2010) Plate tectonics and metallogenesis: examples, Abu Tulu, Mazroub, NE-Nuba Mountains-J. Moya. 3rd. Cairo mining conference, Egypt. Harnmeijer, J. (2003) Banded Iron formation: A continuing enigma. University of Washington.

13 Plate 1.

Plate 2.

14 Plate 3.

Plate 4.

15 Plate 5.

Plate 6.

16 Plate 7.

Plate 8.

17 Plate 9.

Plate 10.

18 Plate 11.

Plate 12.

19 Plate 13.

Plate 14.

21

Fig.1. Ag vs Mn (BIF)

100 80

60

40

Mn ppm Mn 20 0 0 5 10 15 20 25 30

Ag ppm

Fig.2. Ag s Mn (Leona sulphide)

100

80 60 40 Mn ppm Mn 20 0 0 500 1000 1500 2000 2500 3000 Ag ppm

21

Fig.3. Ag vs Fe (BIF)

25 20 15

Fe % Fe 10

5 0 0 5 10 15 20 25 30 Ag ppm

Fig.4. Ag vs Fe (Leona sulphide)

8000

6000

4000

% Fe 2000

0 0 500 1000 1500 2000 2500 3000 Ag ppm

22

Fig.5. Zn vs Ag (BIF)

30 25 20 15

ppm Ag 10 5 0 0 5 10 15 20 25

Zn ppm

Fig.6. Zn vs Ag (Leona sulphide)

3000

2500 2000 1500 ppm Ag 1000 500 0 0 5 10 15 20 25 30 35 40 45 Zn ppm

23

Fig.7. Fe vs Zn (BIF)

25 20

15

10 ppm Zn 5 0 0 5 10 15 20 25

Fe %

Fig.8. Fe vs Zn Leona sulphide)

50

40 30 20 ppm Zn 10 0 0 1000 2000 3000 4000 5000 6000 7000 8000 Fe ppm

24

Fig.9. Pb vs Cu (Leona sulphide)

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Cu ppm Cu 100 50 0 84 86 88 90 92 94 96 98 100

Pb %

Fig.10. Cu vs. Pb (Sodari sulphides).

100

80 Pb % 60 40 20

0 0 2000 4000 6000 8000 10000 12000

Cu ppm

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Fig.11.Cu vs. Zn (Sodari sulphides)

100

80 Zn ppm 60 40

20

0 0 2000 4000 6000 8000 10000 12000

Cu ppm

Fig.12. Cu vs Zn (Leona sulphides)

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30 20

Znppm

10

0 0 50 100 150 200 250 300 350 Cu ppm

26