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Iskou ring complex, Agadez, Nigeri
Regional Level Types
Iskou ring complexComplex
AgadezRegion
NigerCountry

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Latitude & Longitude (WGS84):
18° 4' North , 8° 52' East
Latitude & Longitude (decimal):
18.06667,8.86667
GeoHash:
G#: s5nqcbbtb
GRN:
N13E06
Type:
Complex
Age:
427 ± 20 Ma
Geologic Time:
Ludlow
Dating method:
Rb-Sr whole rock
Reference for age:
Karche, J. P., & Vachette, M. (1978). Age et migration de l'activite magmatique dans les complexes paleozoiques du Niger; consequences. Bulletin de la Société géologique de France, 7(6), 941-953. doi.org/10.2113/gssgfbull.S7-XX.6.941
Köppen climate type:
BWh : Hot deserts climate
Mindat Locality ID:
195735
Long-form identifier:
mindat:1:2:195735:1
GUID (UUID V4):
0
Other/historical names associated with this locality:
Askout; Ashkout; Achkout


Emplaced in Precambrian gneisses and granites the complex has an essentially concentric structure and consists of gabbros and syenites, of which the latter are more abundant.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


8 valid minerals.

Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

ⓘ Albite
Formula: Na(AlSi3O8)
ⓘ Albite var. Oligoclase
Formula: (Na,Ca)[Al(Si,Al)Si2O8]
ⓘ 'Amphibole Supergroup'
Formula: AB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
ⓘ Arfvedsonite
Formula: [Na][Na2][Fe2+4Fe3+]Si8O22(OH)2
References:
consequences. Bulletin de la Société géologique de France, 7(6), 941-953. doi.org/10.2113/gssgfbull.S7-XX.6.941
Karche, J. P., & Vachette, M. (1978). Age et migration de l'activite magmatique dans les complexes paleozoiques du Niger
Leger, J. -M. (1985) Géologie et évolution magmatique du complexe plutonique d'Iskou (Aïr, Niger). Journal of African Earth Sciences (1983), 3 (1-2). 89-96 doi:10.1016/0899-5362(85)90026-0
Moreau, Christian (1987) Les complexes anorogéniques á suite anorthositique de l'Aïr (Niger): contribution à l'étude des anorthosites. Bulletin de la Société Géologique de France, S. 8 Vol. III (1). 115-122 doi:10.2113/gssgfbull.III.1.115
Woolley, A. R. (2001) Alkaline Rocks and Carbonatites of the World, Part 3: Africa - Alkaline Rocks and Carbonatites of the World. The Geological Society of London.
ⓘ Augite
Formula: (CaxMgyFez)(Mgy1Fez1)Si2O6
ⓘ Augite var. Ferroaugite
Formula: (CaxMgyFez)(Mgy1Fez1)Si2O6
ⓘ 'Biotite'
Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
ⓘ 'Clinopyroxene Subgroup'
ⓘ Fayalite
Formula: Fe2+2SiO4
ⓘ 'Fayalite-Forsterite Series'
ⓘ 'Feldspar Group'
ⓘ 'Feldspar Group var. Perthite'
ⓘ 'Ferro-barroisite'
Formula: ◻{CaNa}{Fe2+3Al2}(AlSi7O22)(OH)2
ⓘ Ferro-richterite
Formula: {Na}{CaNa}{Fe2+5}(Si8O22)(OH)2
References:
consequences. Bulletin de la Société géologique de France, 7(6), 941-953. doi.org/10.2113/gssgfbull.S7-XX.6.941
Karche, J. P., & Vachette, M. (1978). Age et migration de l'activite magmatique dans les complexes paleozoiques du Niger
Leger, J. -M. (1985) Géologie et évolution magmatique du complexe plutonique d'Iskou (Aïr, Niger). Journal of African Earth Sciences (1983), 3 (1-2). 89-96 doi:10.1016/0899-5362(85)90026-0
Moreau, Christian (1987) Les complexes anorogéniques á suite anorthositique de l'Aïr (Niger): contribution à l'étude des anorthosites. Bulletin de la Société Géologique de France, S. 8 Vol. III (1). 115-122 doi:10.2113/gssgfbull.III.1.115
Woolley, A. R. (2001) Alkaline Rocks and Carbonatites of the World, Part 3: Africa - Alkaline Rocks and Carbonatites of the World. The Geological Society of London.
ⓘ Hedenbergite
Formula: CaFe2+Si2O6
ⓘ 'Hornblende Root Name Group'
Formula: ◻Ca2(Z2+4Z3+)(AlSi7O22)(OH,F,Cl)2
ⓘ 'Orthopyroxene Subgroup'
ⓘ 'Plagioclase'
Formula: (Na,Ca)[(Si,Al)AlSi2]O8
ⓘ 'Pyroxene Group'
Formula: ADSi2O6
ⓘ Quartz
Formula: SiO2
ⓘ Riebeckite
Formula: ◻[Na2][Fe2+3Fe3+2]Si8O22(OH)2
References:
consequences. Bulletin de la Société géologique de France, 7(6), 941-953. doi.org/10.2113/gssgfbull.S7-XX.6.941
Karche, J. P., & Vachette, M. (1978). Age et migration de l'activite magmatique dans les complexes paleozoiques du Niger
Leger, J. -M. (1985) Géologie et évolution magmatique du complexe plutonique d'Iskou (Aïr, Niger). Journal of African Earth Sciences (1983), 3 (1-2). 89-96 doi:10.1016/0899-5362(85)90026-0
Moreau, Christian (1987) Les complexes anorogéniques á suite anorthositique de l'Aïr (Niger): contribution à l'étude des anorthosites. Bulletin de la Société Géologique de France, S. 8 Vol. III (1). 115-122 doi:10.2113/gssgfbull.III.1.115
Woolley, A. R. (2001) Alkaline Rocks and Carbonatites of the World, Part 3: Africa - Alkaline Rocks and Carbonatites of the World. The Geological Society of London.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Group 9 - Silicates
ⓘFayalite9.AC.05Fe2+2SiO4
ⓘAugite9.DA.15(CaxMgyFez)(Mgy1Fez1)Si2O6
ⓘHedenbergite9.DA.15CaFe2+Si2O6
ⓘAugite
var. Ferroaugite		9.DA.15(CaxMgyFez)(Mgy1Fez1)Si2O6
ⓘ'Ferro-barroisite'9.DE.20◻{CaNa}{Fe2+3Al2}(AlSi7O22)(OH)2
ⓘFerro-richterite9.DE.20{Na}{CaNa}{Fe2+5}(Si8O22)(OH)2
ⓘArfvedsonite9.DE.25[Na][Na2][Fe2+4Fe3+]Si8O22(OH)2
ⓘRiebeckite9.DE.25◻[Na2][Fe2+3Fe3+2]Si8O22(OH)2
ⓘAlbite9.FA.35Na(AlSi3O8)
ⓘvar. Oligoclase9.FA.35(Na,Ca)[Al(Si,Al)Si2O8]
Unclassified
ⓘ'Amphibole Supergroup'-AB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
ⓘ'Biotite'-K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
ⓘ'Feldspar Group'-
ⓘ'var. Perthite'-
ⓘ'Clinopyroxene Subgroup'-
ⓘ'Fayalite-Forsterite Series'-
ⓘ'Hornblende Root Name Group'-◻Ca2(Z2+4Z3+)(AlSi7O22)(OH,F,Cl)2
ⓘ'Plagioclase'-(Na,Ca)[(Si,Al)AlSi2]O8
ⓘ'Pyroxene Group'-ADSi2O6
ⓘ'Orthopyroxene Subgroup'-

List of minerals for each chemical element

HHydrogen
Hⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Hⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
Hⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Hⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Hⓘ Ferro-richterite{Na}{CaNa}{Fe52+}(Si8O22)(OH)2
Hⓘ Riebeckite◻[Na2][Fe32+Fe23+]Si8O22(OH)2
Hⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
OOxygen
Oⓘ AlbiteNa(AlSi3O8)
Oⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Oⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
Oⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Oⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Oⓘ FayaliteFe22+SiO4
Oⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Oⓘ Ferro-richterite{Na}{CaNa}{Fe52+}(Si8O22)(OH)2
Oⓘ HedenbergiteCaFe2+Si2O6
Oⓘ Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Oⓘ QuartzSiO2
Oⓘ Riebeckite◻[Na2][Fe32+Fe23+]Si8O22(OH)2
Oⓘ Fayalite-Forsterite Series
Oⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
Oⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
Oⓘ Pyroxene GroupADSi2O6
Oⓘ Augite var. Ferroaugite(CaxMgyFez)(Mgy1Fez1)Si2O6
FFluorine
Fⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Fⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Fⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
NaSodium
Naⓘ AlbiteNa(AlSi3O8)
Naⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
Naⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Naⓘ Ferro-richterite{Na}{CaNa}{Fe52+}(Si8O22)(OH)2
Naⓘ Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Naⓘ Riebeckite◻[Na2][Fe32+Fe23+]Si8O22(OH)2
Naⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
MgMagnesium
Mgⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Mgⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Mgⓘ Fayalite-Forsterite Series
Mgⓘ Augite var. Ferroaugite(CaxMgyFez)(Mgy1Fez1)Si2O6
AlAluminium
Alⓘ AlbiteNa(AlSi3O8)
Alⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Alⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Alⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Alⓘ Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Alⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
Alⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
SiSilicon
Siⓘ AlbiteNa(AlSi3O8)
Siⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Siⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
Siⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Siⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Siⓘ FayaliteFe22+SiO4
Siⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Siⓘ Ferro-richterite{Na}{CaNa}{Fe52+}(Si8O22)(OH)2
Siⓘ HedenbergiteCaFe2+Si2O6
Siⓘ Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Siⓘ QuartzSiO2
Siⓘ Riebeckite◻[Na2][Fe32+Fe23+]Si8O22(OH)2
Siⓘ Fayalite-Forsterite Series
Siⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
Siⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
Siⓘ Pyroxene GroupADSi2O6
Siⓘ Augite var. Ferroaugite(CaxMgyFez)(Mgy1Fez1)Si2O6
ClChlorine
Clⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Clⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
KPotassium
Kⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
CaCalcium
Caⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Caⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Caⓘ Ferro-richterite{Na}{CaNa}{Fe52+}(Si8O22)(OH)2
Caⓘ HedenbergiteCaFe2+Si2O6
Caⓘ Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Caⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
Caⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
Caⓘ Augite var. Ferroaugite(CaxMgyFez)(Mgy1Fez1)Si2O6
TiTitanium
Tiⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Tiⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
FeIron
Feⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
Feⓘ Augite(CaxMgyFez)(Mgy1Fez1)Si2O6
Feⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Feⓘ FayaliteFe22+SiO4
Feⓘ Ferro-barroisite◻{CaNa}{Fe32+Al2}(AlSi7O22)(OH)2
Feⓘ Ferro-richterite{Na}{CaNa}{Fe52+}(Si8O22)(OH)2
Feⓘ HedenbergiteCaFe2+Si2O6
Feⓘ Riebeckite◻[Na2][Fe32+Fe23+]Si8O22(OH)2
Feⓘ Fayalite-Forsterite Series
Feⓘ Augite var. Ferroaugite(CaxMgyFez)(Mgy1Fez1)Si2O6

Other Regions, Features and Areas containing this locality

AfricaContinent
African PlateTectonic Plate
Niger
North Africa
West AfricaUN Subregion

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Karche, Jean-Paul, Vachette, Michelle (1978) Age et migration de l'activite magmatique dans les complexes paleozoiques du Niger. Consequences. Bulletin de la Société Géologique de France, S7-XX (6). 941-953 doi:10.2113/gssgfbull.S7-XX.6.941
Leger, J. -M. (1985) Géologie et évolution magmatique du complexe plutonique d'Iskou (Aïr, Niger). Journal of African Earth Sciences (1983), 3 (1-2). 89-96 doi:10.1016/0899-5362(85)90026-0
Moreau, Christian (1987) Les complexes anorogéniques á suite anorthositique de l'Aïr (Niger): contribution à l'étude des anorthosites. Bulletin de la Société Géologique de France, S. 8 Vol. III (1). 115-122 doi:10.2113/gssgfbull.III.1.115
Woolley, A. R. (2001) Alkaline Rocks and Carbonatites of the World, Part 3: Africa - Alkaline Rocks and Carbonatites of the World. The Geological Society of London.p.226
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