Hordhac Af Soomaliah: Daraasaddaan waxay muujinaysaa mid ka mid ah macaadinta Soomaaliya oo ku jirta Buur Qalin, Degmada Diinsoor.
Waxay dib u dhaalacaysaa daraasadihii badnaa ee laga qoray birta ku jirta Buur Qalin iyo dhulka u dhow. Dadka Soomaaliyeed waxay u gudbinaysaa wacyi guud iyo sida loo rabo in si casri ah loo baaro, loo soo saaro; ka dibna la iib geeyo maxsuulka si ay u dhaliso dakhli xoog leh iyo shaqooyin ay helaan dadka maxalliga ah iyo Soomaalida dhammaan.
Soo-saarka birta Buur Qalin waxaa hortaagnaa, ka sokow amni darrada, tamar la’i laakiin taknoolojiyada Tamar Qorraxeed ka waxay noo suurta-gelinaysaa in mashruucaan dib u eegno oo laga shaqo-galo soo-saarka birta. Caqabado kale ee hortaagan Buur Qalin waa waddo la’aan iyo dekad u dhow oo laga dhoofin karo birta. Hasayeeshee, intaasi xal bay yeelan karaan mar haddii tamarta ay xallisan tahay.
Geologists have accepted that the global Banded Iron Formations (BIF) were formed in an event that happened a long time ago. It was an unusual, one-off event. This is different than many other types of mineralisation whose process are on-going.
For example active volcanoes such as those in North-Eastern Ethiopia or in the Afar Depression show us mineralisation that is occurring to the present day. Others are related to undersea hydrothermal activities which continue to the present. The Red Sea and the Gulf of Aden facing Puntland, nearby areas of Somalia are examples of undersea mineral formation.
However, the Banded iron formations (BIFs) are different – they were all formed at a time where the earth had a different environment than what it is today.
These deposits of Banded Iron Formations are critical to the economy of Somalia. According to the data we have now, the deposit is modest; not very large in comparison to the ones in Australia, Brazil, China or in Minnesota, USA but if developed – explored properly, produced, separated and processed, it will contribute a lot to the economy of Somalia.
These deposits were discovered in the late fifties and studied by some Italians, Germans and local geologistsl during the 60s-80s and no further step was taken. The time has come these deposits should be considered thoroughly to improve the Somali economy and raise the quality of life of the people. If thoroughly explored this deposit could be larger than the current size of deposit we estimate.
An image of banded iron in quartzite, from Bur Qalin
What is a BIF rock?
A BIF is hard and heavy meta-sedimentary stone. The bands are composed of narrowly banded sedimentary rocks which alternate a variety of iron rich layers with fine grained quartz (chert) layers. Some of the common minerals associated with BIFs include:
hematite or magnetite (iron oxide)
siderite (iron carbonate)
stilpronmelane (iron, magnesium alluminosilicate)
Banded iron formations are critical to our current economy as they are by far the biggest source of economic iron deposits. China and Australia are the world’s largest iron producers, and both have enormous reserves of BIFs. Smaller deposits are mined elsewhere including the USA and Canada.
How Are BIFs Formed?
The Earth was cooling down at around 2400 million year ago and most BIFs date from around that age, in the extremely early days of earth’s evolution, during the Archaen Era. They were created in conditions that will never occur again. BIFs are the product of an epochal change in the world’s atmosphere known as the “great oxygenation event”.
At that time, the world was covered with acidic, iron-rich oceans and had an atmosphere without oxygen. The only life forms were primitive algae. The evolution of blue-green algae (cyanobacteria) changed the world. These algae formed reef-like structures called stromatolites, not unlike the coral reefs of today.
The bacteria were photosynthetic – a chemical reaction that releases oxygen. Iron is highly reactive with oxygen, which is why your old car rusts so quickly, so the bacteria caused iron oxides to form and settle in the ancient oceans. As the cyanobacteria continued to multiple, eventually most of the iron in the seawater had been removed, and the oxygen began to escape into the atmosphere, resulting eventually in the atmosphere that we are dependent on today.
For 2 billion years, blue-green algae were the dominant life form on earth. They are no longer dominant, but they are not extinct, they were rather over-whelmed by all the oxygen dependent life that they helped create, but they still survive in isolated areas. Stromatolites can be seen in Western Australia – right next door to the world’s largest deposit of banded iron formations, which they helped form and in Southern Africa.
In Somalia the largest deposits of BIF is at Buur Qalin. though there are four minor deposits in the Dooy – the vicinity. A comprehensive exploration is required to prove the existence of other BIF deposits in this rich area. Some geologists talk about secondary enrichment whereby a process of secondary enrichment of the deposits takes place either by a hydrothermal process or by chemical weathering and leaching of soluble materials. Both of these can result in high-grade hematite (martite) and goethite-rich deposits that can contain 50-68% iron.
The result of chemical analysis on Bur Qalin and its nearby deposits
|A (%)||B (%)||C(%)||D(%)|
|The rest are oxides of Ti, Al, Mn, Mg, Ca, Na, K, P and water in very small percentages or in traces. All the iron is in the form of Fe2 O3|
A summary of the iron ore of the SW State of Somalia: Bur Galin (Buur Qalin and four more deposits in the vicinity of Buur Qalin)
|Geographic coordinates of the deposit||43.50109 E , 2.31805 N (WGS84) only Bur Qalin|
|Mineral types||Hematite and magnetite|
|Analytical data:||39% (by Holmes), 64.2%, 49.6% , 56.7% and 55.3% in an analysis carried out by some Italian researchers in various areas of Bur Qalin. The percentages are in Fe2 o3.
|Host or associated||Host: Banded hematite quartzite in quartzite;|
|Rock type||Metamorphic rock: Meta-sedimentary rock -quartzite; Banded iron formation (BIF).|
|Stratigraphic age||Neoproterozoic; The Neoproterozoic Era is the unit of geologic time from 1,000 to 541 million years ago.|
|Bur Crystalline Area (Dooy area)||Metamorphic and/or plutonic terrain; Archean|
|Geologic structure type
|Ore body information|
|Dip||90 – 55 ˚|
|Economic information about the deposit|
|Development status||Occurrence; small exploration pits were dug|
|Deposit size||Medium; Holmes (1954) estimates 29 million metric tons of ore which is very conservative. The real estimate goes beyond hundred metric tons of ore. There are other deposits of the same size Dhaimir and its vicinity|
|Shortened Bibliographic references:
1. Holmes, R.J. 1954: A reconnaissance survey of the mineral deposits of Somalia (Former Italian Somaliland) – US Technical Assistance Mission (T.A. 45-125) Report; 83P
2. Bakos F and Sassi F.P 1979. The Crystalline Basement of Bur Area, Quaderni Di Geologia Della Somalia.
3. Daniels J 1965. A photogeological interpretation of Bur Region, Somali Republic, Overseas Geol, Min, Ros. Vol. 9. pp: 427-436.
4. Ibrahim H A and Sassi F P: 1977. Il basamento crystallino della Somalia. Quaderni Di Geologia Della Somalia
5. Raniero Massoli and Novelli. 1981. Il deposito ferrifero Precambrico di Bur Galan. Southern Somalia. Associazione Subalpina, Anno: XVIII, n. 1-2.
– Apologies for not ordering the list alphabetically.
Abdulkadir Abiikar Hussein