Sudan has been an important gold producer over a long period of time, possibly for over 3000 years. However because of the sparse population and inhospitable climate, Sudan has only been prospected in a sporadic and ephemeral manner.
During the period 1901-1904 exploration was carried out by a number of British Companies in the Red Hills area. This brief period of exploration resulted in the Development of the Omm Nabardi and Gebeit Mines.
A small group of companies carried out exploration between 1929 and 1939. This lead To the development of small mines at Oyo, Ohaff, Gebeit, Rigag Sageib, Uar, Onib, And Aberkateib in the Red Sea Hills: Doishat near Wadi Halfa and allvial Workings at Fazugli-Queissan in the Blue Nile area and near Kapoeta in the Southern east of the Sudan.
Between 1980- 1985, work by British and French organizations in the Red Sea Hills Resulted in new discoveries of gold at Gebeit and Wadi Ariab areas (200 km west Of Port Sudan). All the exploration prior to 1980 was based on the traditional Method of prospecting outcropping quartz veins, and all mines developed were Small vein type underground mines.
During the last ten years the gold mine industry has developed a substantial body of Knowledge, linked to recently developed technology that has resulted in the Discovery and development of many new types of gold deposits that could not Be detected by the traditional prospecting techniques.
This modern gold exploration technology is only just beginning to be applied in Sudan, Nut its already yielding significant result including the discovery of several major Base-- metal - gold deposits associated with silica-barite- gossans in the Ariab area Which are detailed in the following table:

Sudan consists of typical pre-Cambrian continental carton of granite-gneiss Terrain with occasional long narrow green stone belts. In Sudan as in other "Shield area" virtually all the gold and base metal deposits occur in the green Stone belts. The green stone consists of basic and ultra basic rocks that Represent compressed and deformed slices of oceanic crust often referred to as ophiolites. Experience in other countries indicates that within these "green stone" or ophiolies, there are three statigraphic horizons which contain Mineral deposits. These area:

1. The lower "mantle" rocks of dunite- harzburgite composition which contain Chromite and perhaps platinum mineralization. Generally, this horizon occurs In Sudan only as at Hamissana-Sol Hamed, /Ingassana and in the southwest Nuba Mountains.
   
2. The lower contact of the basalt-andesite volcanic with underlying mantle rocks as Peridotite, harzburgite and gabbro which contain copper, nickel, platinum sulpides Of the kambalda type. This horizon is not well preserved in the greenstone belts In the Sudan but small remnants occur in the Onib, Wadi Amur and Ingassana Hills Area.
   
3. The upper contact of the basalt- andesite volcanic with overlying chemical sediments such as cherts and banded Iron Formation as in the Nuba Mountains and possibly Hofrat En Nashas or overlying acid volcanic as in the Ariab. This horizon contains Widespread gold and base metals (Cu-pb-Zn-Ba) sulphide mineralization. Where the rocks have been metamorphasized, the gold is often re-mobilized into Typical gold -bearing quartz veins. This horizon has been recognized in the Onib Area, near Gebeit, in the Ariab - Wadi Amur area Derudeb, in the eastern part Of the Ingassana Hills, in Nuba Mountains at Kapoeta in Equator and possibly In Hofrat En Nahas in Darfur, east of the River Nile between Wadi Halfa as well as At Wadi Gabgaba in the northern part of Sudan.

These areas are all known to be gold bearing and there is widespread evidence that of Sulfide mineralzation. Much of the gold mineralzation occurs fine-grained gold Associated with pyrite and in its natural state the gold is so fine grained that often it Can not be detected by traditional panning methods, but only by chemical analysis.
The contact zones between basalt-andesite volcanic are highly prospective for both Gold and base metals and should be regarded as priority targets.

Its strongly recommended that all the green stone-ophiolite belts in the Sudan should be Geologically mapped in detail and air-borne mangnetics should be correlated with Geology to assist with interpretation of the sub-surface geology and structure.
Where the upper contact of the basalt- andesite volcanic is located, with overlying Chemical sediments or acid volcanic is located it should be systematically explored For gold-base metal sulfide mineralization.

Where the lower contact of the basalt-andesite volcanic with underlying abbro- Basic rock is located, it should be systematically explored for copper-nickel- Platinum sulfide mineralization. This type of conceptual geological exploration Requires a high risk, high technology, long term commitment and is bast suited To the export oriented mining companies.
Local Sudanese investors and artesian miners should be encouraged to develop small Scale workings of the traditional type base on shallow quartz veins and alluvial Mining which can be carried out profitably with simple technology suited to use In remote areas. Special assistance should be given to the local artsanal miners in The Fazugli and Kapoeta areas where alluvial mining currently produces, Significant quantities of gold and represents an important source of income for the Local communities. The available data indicates that there is substantial scope to Increase the scale of these workings by introducing mechanized equipment such as Backhoes suction dredges and sluice boxes.

The Red Sea Hills are composed of Pre-Cambrian metamorphic rocks consisting of A granite basement overlain by or including within it, the Niferdeib "green Stone " sequence. The relationship between the Niferdeib green stone and Granite gneiss terrace has been established, but the Niferdeib has all the Characteristics of an expensive overthrust ophiolite sequence. Virtually all The known mineralization in the Red Sea Hills occurs within the Niferdeib Green stone.
The Niferdeib green stone appear to have five recognizable, sub-parallel "green stone" Ophiolite belts trending roughly northeast. They are from north to south.

(a) Onib-Hamissana-Sol Hamed Belt
(b) Serakoit-Gebeit-Fodikwan Belt
(c) Ariab- Oshib-Arbaat Belt
(d) Derudeb-sinkat beltM
(e) Karora belt.

Onib-Hamissana- Sol Hamed belt

The base metal gold volcanogenic sulfide deposits occurring along the upper Contact of the basalt- andesite volcanic within the overlying cherts, limestone, Chemical sediments and acid volcanic are likely to exist in the Hamssana area in View of the reported occurrence of pyretic metasediments ferruginous cherts, Limestone, acid volcanic, widespread minor gold values and pillow basalt's in the Vicinity of the Onib gold mine and gold -bearing ochre horizons at Eight gold Mine (BRGM Report 82 SUD002).

Serakoit-Gebeit-Fodikwan belt.

This is the least well developed of the Red Sea Hills green stone belts and consists Predominately of andesitic basalt volcanic with overlying sediments, limestone And acid volcanic. No ultra basics are known although a talc occurrence is Reported at Jebel Tomhia near Fodikwan. The mineral potential is therefore Restricted to the upper volcanic chemical sediments-acid volcanic Contac Related type base metal-gold mineralization. Several minor gold occurrences occur between Serakoit and Fodikwan but the only Known deposits of significance are Serakoit and Gebeit. At Serakoit, gold copper mineralization occurs in a weekly developed quartz vein Stock works intruded adjacent to the contact zone between basaltic andesite And rhyolite acid volcanic and accompanied by intrusive sericitic-argillic Alteration of the wall rocks. The gold bearing quartz veins system extends For 2 km in northeasterly direction and there is a 200mx500m copper Geochemical anomaly about 500m to the east of the gold-bearing vein system. Gebeit is an ancient gold mine, which was worked intermittently between 1904-1989. The gold occurs in quartz veins some 2-km in length, which are intruded into Pyretic black shale and metasediments along the contact between andesitis Basalt, agglomerates and acid volcanic. There is no base metal association. Known reserves in 1986 were375, 000 tons at 15-gm/t gold.

Ariab- Oshib-Arbaat belt

The Ariab green stone ophiolite belt is the best known explored, having been Investigated since 1979 by a combined Sudanese- French team. The Ariab belt Extends from the coastal plain at Arbaat (20 km north of Port Sudan) southwest For 250 km to Wadi Amur (70 km north of Musmar) and has a width of about 30-40 km. The green stone ophiolite Complex has been strongly tectonized and Consists of the Oshib sedimentary belt along the southern side. Historically, the Ariab base-metal-gold deposit was known for its numerous showing Of manganese, copper and gold, some of which has been worked in minor way During the last ten years, systematic exploration along the Ariab belt has resulted In the discovery of more than twenty goassanous outcrops of volcanogenic copper, Zinc, lead, gold, silver, barite, manganese and Iron mineralization, some of which Are of considerable commercial interest. Most of the gold bearing deposits have developed zones of secondary enrichment in the Oxide zones to depths of 200-50 meters and the exploration of these auriferous Gossans is the subject of a feasibility study at the present time.

The base metal potential has not been investigated although the geological Setting is prospective for massive sulfide deposits. The remoteness of the Area would require a major long term commitment to exploration and Development to be of interest, any base metal discovery would have to be Both very large and of high grade.
The Nubian Desert is considered to have some potential for the development Of scale gold mining in the area close to the Nile River that would be of Interest to local companies. Long term potential for the discovery of base Metal deposits east of Wadi Gabgaba exists. Examples of gold prospects East of Khor Gabgaba is:

Minor gold values occur in the primary sulfide zones (estimated reserves 10 million Tons) and these have been enriched in the oxide zone to level of 1 to 3 g/t with Some surface samples assaying up to 10 g/t.
Preliminary beneficial test work has shown that mineralization is amenable to Conventional processing and by cyanide leaching to recover gold and the Copper in the oxide zone.

A green stone ophiolite belt extends for length of 70 km with a width of 40 km Between EL Terter and Abu Gebeiha. Individual gosaan outcrops are up to 1200 x 200 msq in extent and appear to be deeply weathered and leached with Surface values up to 5% Zn, 0. 19% Cu, 0.1% Pb, 0.8% Ni, 0.2% Ba, 0.60% As and 2000ppb Hg.
This large extent of gossans and their easy access, about 100km south of the railway Along El Terter- Abu Gebeiha road, make them of potential commercial Interest for large tonnage base metal gold deposits.

This area is virtually unknown in terms of it is mineral resources with only a few Regional surveys having been carried out in the 1970s most of the area is Geological unmapped and covered by extensive soil and latrines.
The gold occurrences at Kapoeta area consist of reported high grade in situ Mineralization associated with small outcrops of serpentinized ultra mafic Rocks and also extensive alluvial deposits. Little information is available Concerning most of the gold occurrences, in the area south of Juba.
The local people have a strong tradition of gold mining and therefore it would be Sensible to encourage the development of a small scale mining by providing Government assistance with geological mapping, geo chemical surveys and Basic exploration to identify reserves. The small green stone- ophiolite belt In Kapoeta area has to be geologically mapped and investigated in detail.