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Nairobi Volcanic area, Nairobi County, Kenyai
Regional Level Types
Nairobi Volcanic areaVolcanic Field
Nairobi CountyCounty
KenyaCountry

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Latitude & Longitude (WGS84):
1° South , 36° East (est.)
Estimate based on other nearby localities or region boundaries.
Margin of Error:
~28km
GRN:
S01E26
Type:
Volcanic Field
Age:
13.4 to 0.8 Ma
Geologic Time:
Cenozoic
Dating method:
K-Ar
Reference for age:
Saggerson, E. P. (1991). Geology of the Nairobi area (No. 98). Mines & Geological Department.
Köppen climate type:
Cfb : Temperate oceanic climate
Mindat Locality ID:
407019
Long-form identifier:
mindat:1:2:407019:4
GUID (UUID V4):
0


The rocks of the area consist of a succession of lavas and pyroclastics of Cenozoic age overlying folded Precambrian schists and gneisses of the Mozambique belt (Saggerson 1991). The western third of the area is cut by numerous sub-parallel faults that form the eastern flank of the Gregory Rift Valley.

Tuffs are quarried for building stone and phonolite is quarried for aggregate, roadstone etc.

Approx coords range: 1º00' - 1º30'S; 36º30' - 37º00'E.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


10 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:

ⓘ Aegirine
Formula: NaFe3+Si2O6
ⓘ Aegirine-augite
Formula: (NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6
ⓘ Aenigmatite
Formula: Na4[Fe2+10Ti2]O4[Si12O36]
ⓘ Albite
Formula: Na(AlSi3O8)
ⓘ Albite var. Anorthoclase
Formula: (Na,K)AlSi3O8
ⓘ 'Alkali Feldspar'
ⓘ 'Alkali pyroxene'
ⓘ 'Amphibole Supergroup'
Formula: AB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
ⓘ Analcime
Formula: Na(AlSi2O6) · H2O
ⓘ 'Biotite'
Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
ⓘ Katophorite
Formula: {Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
ⓘ Nepheline
Formula: Na3K(Al4Si4O16)
ⓘ Quartz
Formula: SiO2
ⓘ Sanidine
Formula: K(AlSi3O8)
ⓘ Sodalite
Formula: Na4(Si3Al3)O12Cl
ⓘ 'Sodic amphibole'
ⓘ 'Zeolite Group'

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Group 9 - Silicates
ⓘAegirine-augite9.DA.20(NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6
ⓘAegirine9.DA.25NaFe3+Si2O6
ⓘKatophorite9.DE.20{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
ⓘAenigmatite9.DH.40Na4[Fe2+10Ti2]O4[Si12O36]
ⓘNepheline9.FA.05Na3K(Al4Si4O16)
ⓘSanidine9.FA.30K(AlSi3O8)
ⓘAlbite9.FA.35Na(AlSi3O8)
ⓘvar. Anorthoclase9.FA.35(Na,K)AlSi3O8
ⓘSodalite9.FB.10Na4(Si3Al3)O12Cl
ⓘ'Zeolite Group'9.G0.
ⓘAnalcime9.GB.05Na(AlSi2O6) · H2O
Unclassified
ⓘ'Alkali Feldspar'-
ⓘ'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
ⓘ'Sodic amphibole'-
ⓘ'Alkali pyroxene'-

List of minerals for each chemical element

HHydrogen
Hⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Hⓘ AnalcimeNa(AlSi2O6) · H2O
Hⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Hⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
OOxygen
Oⓘ AegirineNaFe3+Si2O6
Oⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Oⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Oⓘ AlbiteNa(AlSi3O8)
Oⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Oⓘ AnalcimeNa(AlSi2O6) · H2O
Oⓘ Albite var. Anorthoclase(Na,K)AlSi3O8
Oⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Oⓘ NephelineNa3K(Al4Si4O16)
Oⓘ QuartzSiO2
Oⓘ SanidineK(AlSi3O8)
Oⓘ SodaliteNa4(Si3Al3)O12Cl
Oⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
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
NaSodium
Naⓘ AegirineNaFe3+Si2O6
Naⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Naⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Naⓘ AlbiteNa(AlSi3O8)
Naⓘ AnalcimeNa(AlSi2O6) · H2O
Naⓘ Albite var. Anorthoclase(Na,K)AlSi3O8
Naⓘ NephelineNa3K(Al4Si4O16)
Naⓘ SodaliteNa4(Si3Al3)O12Cl
Naⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
MgMagnesium
Mgⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Mgⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Mgⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
AlAluminium
Alⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Alⓘ AlbiteNa(AlSi3O8)
Alⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Alⓘ AnalcimeNa(AlSi2O6) · H2O
Alⓘ Albite var. Anorthoclase(Na,K)AlSi3O8
Alⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Alⓘ NephelineNa3K(Al4Si4O16)
Alⓘ SanidineK(AlSi3O8)
Alⓘ SodaliteNa4(Si3Al3)O12Cl
Alⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
SiSilicon
Siⓘ AegirineNaFe3+Si2O6
Siⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Siⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Siⓘ AlbiteNa(AlSi3O8)
Siⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Siⓘ AnalcimeNa(AlSi2O6) · H2O
Siⓘ Albite var. Anorthoclase(Na,K)AlSi3O8
Siⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Siⓘ NephelineNa3K(Al4Si4O16)
Siⓘ QuartzSiO2
Siⓘ SanidineK(AlSi3O8)
Siⓘ SodaliteNa4(Si3Al3)O12Cl
Siⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
ClChlorine
Clⓘ Amphibole SupergroupAB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2
Clⓘ SodaliteNa4(Si3Al3)O12Cl
KPotassium
Kⓘ Albite var. Anorthoclase(Na,K)AlSi3O8
Kⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Kⓘ NephelineNa3K(Al4Si4O16)
Kⓘ SanidineK(AlSi3O8)
CaCalcium
Caⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Caⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
TiTitanium
Tiⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
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ⓘ AegirineNaFe3+Si2O6
Feⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Feⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Feⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2

Geochronology

Mineralization age: Neogene : 13.4 Ma to 5.2 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic TimeRocks, Minerals and Events
Phanerozoic
 Cenozoic
  Neogene
   Pliocene
ⓘ Phonolite (youngest age)5.2 Ma
   Miocene
ⓘ Phonolite (oldest age)13.4 Ma

Other Regions, Features and Areas containing this locality

AfricaContinent
African Plate
Somali PlateTectonic Plate

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

Saggerson, E. P. (1991). Geology of the Nairobi area (No. 98). Mines & Geological Department.
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.134
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