288:, with estimated reserves of 200,000 tons. Low global demand for uranium has driven down production for more than 30 years since 1986. There may be other reserves at Imouraren, Afasto Ouest, Abkorum-Azelik, Afasto Est, Tassa N'Taghalgue and Teguida N'Tessoun, with uranium concentrations ranging between 0.22 and 0.45 percent. Molybdenum is often produced as a byproduct of uranium mining. Niger also has vein-type copper deposits, with
185:
ring complexes with significant variety in structure and rock type formed in the Air Massif. In fact, the Air Massif has the largest ring-dike in the world, with a diameter of 65 kilometers. Geologists subdivide the different ring complexes into three different types. The
Taghouaji-type has plutonic
392:
in the
Abuzegueur overthurst, in the Air region also show potential for platinum mineralization and may also have chromite, nickel and cobalt. The Fantio deposit in the Liptako area has heavily weathered ultra-mafic rocks, with 0.8 percent nickel, totaling up to as much as 200,000 tons. Makalondi,
312:
and small amounts of petroleum. The
Liptako area in the northeast is the terminus of the West African gold belt, which extends from the Atlantic in Ghana. It hosts gold in the Birimian greenstones of Tera-Gasso and Gorouel belts. The gold belt actually extends further east, past the Niger River,
283:
Mined uranium is Niger's biggest export, but mining remains a relatively small part of GDP. The country also has gold and coal and deposits of tin and phosphate were mined in the past. Uranium is extracted from two concessions at Arlit and Akouta, more than 200 kilometers northwest of
307:
Relatively low-grade coal formed in a small basin at Anou-Araren, with estimated reserves of 10 megatons. Because of its poor quality, it is mainly used to provide electricity for uranium mines. The
Iullemeden Basin contains
157:
rocks, with the oldest rocks near the edge of the basin. After the 50 percent of basement rocks that are metamorphic, the rest of the rocks in the Air Massif Renatt type and Dabaga type granite, which formed during the
396:
Iron is common in Niger, in rocks from the
Precambrian through the Cenozoic, although the Cenozoic rocks of the Termit-Agadem and Ader-Doutchi regions have the highest iron concentrations, at up to 55 percent.
313:
but is largely concealed by younger sediments and sedimentary rocks. Gold mineralization also occurs in shear-related quartz veins. Some gold has been freed from sulfides in these veins by
186:
alkaline rocks and may have peralluminous granites while the Goudai-type is mainly acid volcanic rocks. The Ofoud-type is the most varied, encompassing gabbros, granites and anorthosite.
321:. Silver mineralization occurs where greenstones and granite intrusions meet, in the same quartz veins that host gold and sulfides. The silver is typically mineralized within
134:. More than half of the basement rock in the massif is metamorphic, including the Edoukel mesozonal micaschist, Azanguerene gneiss, Tafourfouzete letpynite and possible
845:
615:
178:
formed ring complexes, that now comprise 30 different massifs in the Niger-Nigerian
Younger Granite Province. The oldest, Cambrian massifs formed in the north.
464:
Favreau; et al. (2009). "Estimating specific yield and transmissivity with magnetic resonance sounding in an unconfined sandstone aquifer (Niger)".
760:
600:
537:
620:
206:
20:
comprises very ancient igneous and metamorphic crystalline basement rocks in the west, more than 2.2 billion years old formed in the late
401:
hosted, granite and sedimentary deposits of tin were mined commercially from 1984 until 1991 in the Air Massif. Today, only small scale
871:
635:
914:
369:
sediments. The
Tidekelt region has up to 25 million tons of salt brines, with a yield of 70 percent sodium chloride.
197:. Sedimentary rocks from the Paleozoic, thicken toward the mountains and to the south. East of Tamesna, Cambrian and
530:
111:
gneiss which are younger. These rocks formed after a granite-gneiss complex in the area, but before the mudstones,
205:
between these deposits and glacial sediments, associated with the widespread glaciation and global cooling of the
944:
918:
675:
127:
of the
Amarasinde and Bellekoire beds. These Upper Birimian Supergroup rocks are intruded by younger granites.
296:
associated with molybdenum, lithium and silver—or zinc and lead in the Proche-Tenere
District. Native copper,
910:
785:
775:
580:
189:
The
Iullemeden Basin at Tamesna began to form in the Paleozoic. The center of the basin was uplifted by the
790:
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770:
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725:
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There are some indications of platinum in the Makalondi District, south of Liptako, associated with
825:
800:
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625:
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575:
221:
201:
sedimentary rocks are up to 500 meters thick and include conglomerates and sandstones. There is an
159:
53:
60:
weathering including uranium, molybdenum, iron, coal, silver, nickel, cobalt and other resources.
52:, along with numerous ring complexes, as the region experienced events such as glaciation and the
897:
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263:, before drying out and shifting from marine sediment deposition to continental sediments.
805:
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rocks common in much of West Africa. The pre-Birimian crystalline basement rocks include
477:
346:
210:
154:
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330:
326:
293:
202:
69:
56:. Today, Niger has extensive mineral resources due to complex mineralization and
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297:
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topped off the Iulllemeden Basin with marine sedimentary rocks, often on top of
147:
131:
96:
88:
73:
33:
29:
25:
357:. The Tahoua deposit, 375 kilometers northeast of the capital contains nodular
485:
389:
322:
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244:
213:
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37:
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289:
260:
182:
135:
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terrestrial sedimentary rocks. The region remained flooded well into the
248:
232:
217:
171:
150:
100:
76:
57:
393:
also in Liptako, hosts chromium concentrations of 5.1 to 17.4 percent.
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358:
309:
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21:
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weathering due to heavy rainfall in the last 2.5 million years of the
366:
342:
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285:
272:
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104:
80:
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519:
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is overlain by shales and limestones, which contain coral and
447:
445:
275:
Continental Terminal is an unconfined sandstone aquifer.
209:. In ascending order, glacial deposits are overlain by
107:, meta-andesite, meta-arkose, micaceous quartzites and
72:
and northern Ghana predate the 2.2 billion year old
859:
834:
553:
68:The oldest rocks in Niger, along the border with
271:Hydrogeology in Niger is poorly researched. The
162:mountain building event 600 million years ago.
142:Neoproterozoic (1 billion-539 million years ago)
341:. One hundred thirty five kilometers south of
64:Stratigraphy, Tectonics & Geologic History
531:
304:are found in sediments in the Agadez region.
8:
239:Mesozoic-Cenozoic (251-66 million years ago)
153:along the border with Burkina Faso contains
174:as multi-cellular life became commonplace,
538:
524:
516:
506:
451:
436:
414:
227:A coal bearing layer, likely tied to a
95:. The Liptako region, in the west has
166:Paleozoic (539-251 million years ago)
7:
207:Ordovician-Silurian extinction event
130:The Air Massif began to form in the
14:
345:, is the Tapoa phosphate deposit
846:Sahrawi Arab Democratic Republic
616:Democratic Republic of the Congo
243:A marine transgression in the
1:
138:of the Aouzeueur formation.
961:
424:Geological Atlas of Africa
220:sandstones and shales and
486:10.1007/s10040-009-0447-x
422:SchlĂĽter, Thomas (2008).
353:sedimentary rocks of the
91:grade in the sequence of
601:Central African Republic
426:. Springer. p. 190.
279:Natural resource geology
761:SĂŁo TomĂ© and PrĂncipe
621:Republic of the Congo
44:began to form in the
466:Hydrogeology Journal
229:marine transgression
224:deltaic sandstones.
176:anorogenic magmatism
836:States with limited
509:, pp. 192–193.
478:2009HydJ...17.1805B
222:Early Carboniferous
160:Pan-African orogeny
54:Pan-African orogeny
547:Geology of Africa
247:, during the late
93:metamorphic facies
932:
931:
863:other territories
636:Equatorial Guinea
259:, throughout the
191:Hercynian orogeny
87:metamorphosed to
952:
945:Geology of Niger
924:
923:(United Kingdom)
919:Tristan da Cunha
915:Ascension Island
907:
894:
885:
861:Dependencies and
554:Sovereign states
540:
533:
526:
517:
510:
504:
498:
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472:(7): 1805–1815.
461:
455:
449:
440:
434:
428:
427:
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403:artisanal mining
253:Early Cretaceous
195:Hoggar Mountains
42:Iullemeden Basin
18:geology of Niger
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386:chloritoschists
281:
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181:Throughout the
168:
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12:
11:
5:
958:
956:
948:
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872:Canary Islands
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454:, p. 192.
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439:, p. 190.
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347:Neoproterozoic
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211:Early Silurian
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155:Neoproterozoic
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46:Neoproterozoic
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676:Guinea-Bissau
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507:SchlĂĽter 2008
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452:SchlĂĽter 2008
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437:SchlĂĽter 2008
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35:
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27:
23:
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911:Saint Helena
882:
786:South Africa
776:Sierra Leone
745:
581:Burkina Faso
502:
469:
465:
459:
432:
423:
417:
395:
371:
331:arsenopyrite
327:chalcopyrite
306:
294:chalcopyrite
282:
270:
267:Hydrogeology
242:
226:
203:unconformity
193:to form the
188:
180:
169:
145:
129:
121:conglomerate
70:Burkina Faso
67:
28:eons of the
17:
15:
838:recognition
791:South Sudan
681:Ivory Coast
405:continues.
382:anorthosite
355:Volta Group
298:chrysocolla
170:During the
148:Volta Basin
132:Precambrian
97:amphibolite
89:amphibolite
74:Proterozoic
34:Volta Basin
30:Precambrian
26:Proterozoic
893:(Portugal)
851:Somaliland
771:Seychelles
736:Mozambique
721:Mauritania
706:Madagascar
661:The Gambia
596:Cape Verde
409:References
390:Ophiolites
376:lenses in
323:sphalerite
319:Quaternary
245:Cenomanian
214:graptolite
199:Ordovician
38:Air Massif
726:Mauritius
494:129592122
399:Pegmatite
363:Paleocene
339:covellite
290:malachite
261:Paleocene
235:fossils.
183:Paleozoic
136:ophiolite
125:greywacke
117:quartzite
85:migmatite
50:Paleozoic
939:Category
917: /
913: /
906:(France)
900: /
878: /
874: /
826:Zimbabwe
801:Tanzania
651:Ethiopia
646:Eswatini
626:Djibouti
591:Cameroon
576:Botswana
374:chromite
351:Cambrian
315:laterite
257:Cenozoic
249:Mesozoic
233:conodont
218:Devonian
216:shales,
172:Cambrian
151:syncline
101:chlorite
77:Birimian
58:laterite
40:and the
902:RĂ©union
898:Mayotte
889:Madeira
884:(Spain)
880:Melilla
811:Tunisia
781:Somalia
766:Senegal
751:Nigeria
741:Namibia
731:Morocco
696:Liberia
691:Lesotho
641:Eritrea
611:Comoros
586:Burundi
561:Algeria
474:Bibcode
378:gabbros
359:apatite
310:lignite
302:cuprite
22:Archean
921:
904:
891:
821:Zambia
816:Uganda
756:Rwanda
711:Malawi
671:Guinea
566:Angola
492:
367:Eocene
343:Niamey
335:pyrite
286:Agadez
273:Eocene
109:garnet
105:schist
81:gneiss
32:. The
876:Ceuta
796:Sudan
746:Niger
701:Libya
686:Kenya
666:Ghana
656:Gabon
631:Egypt
571:Benin
490:S2CID
806:Togo
716:Mali
606:Chad
384:and
365:and
349:and
300:and
292:and
146:The
123:and
113:tuff
83:and
48:and
24:and
16:The
482:doi
361:in
337:or
941::
488:.
480:.
470:17
468:.
444:^
388:.
380:,
333:,
329:,
325:,
119:,
115:,
99:,
36:,
539:e
532:t
525:v
496:.
484::
476::
103:-
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