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Nyambeni Hills Volcanic Field, Meru County, Kenyai
Regional Level Types
Nyambeni Hills Volcanic FieldVolcanic Field
Meru CountyCounty
KenyaCountry

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Type:
Volcanic Field
Age:
4.5 ± 0.25 to 0.46 ± 0.06 Ma
Geologic Time:
Cenozoic
Dating method:
K-Ar
Reference for age:
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E. M., & Traversa, G. (1984). Miocene to Quaternary volcanism in eastern Kenya: sequence and geochronology. Tectonophysics, 101(1-2), 75-86. doi.org/10.1016/0040-1951(84)90043-X
Mindat Locality ID:
406897
Long-form identifier:
mindat:1:2:406897:9
GUID (UUID V4):
0


The volcanic field lies immediately to the NE of, and is continuous with the Mount Kenya centre, but is older. It extends over an area of about 150 x 100 km.

Approx coords range: 0º00' - 0º51'N; 37º10' - 38º29'E.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


6 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-augite
Formula: (NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ Aenigmatite
Formula: Na4[Fe2+10Ti2]O4[Si12O36]
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ Analcime
Formula: Na(AlSi2O6) · H2O
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ Katophorite
Formula: {Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ Nepheline
Formula: Na3K(Al4Si4O16)
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ 'Plagioclase'
Formula: (Na,Ca)[(Si,Al)AlSi2]O8
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ 'Pyroxene Group'
Formula: ADSi2O6
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
ⓘ Sanidine
Formula: K(AlSi3O8)
References:
Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 9 - Silicates
ⓘAegirine-augite9.DA.20(NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)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)
ⓘAnalcime9.GB.05Na(AlSi2O6) · H2O
Unclassified
ⓘ'Plagioclase'-(Na,Ca)[(Si,Al)AlSi2]O8
ⓘ'Pyroxene Group'-ADSi2O6

List of minerals for each chemical element

HHydrogen
Hⓘ AnalcimeNa(AlSi2O6) · H2O
Hⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
OOxygen
Oⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Oⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Oⓘ AnalcimeNa(AlSi2O6) · H2O
Oⓘ NephelineNa3K(Al4Si4O16)
Oⓘ SanidineK(AlSi3O8)
Oⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
Oⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
Oⓘ Pyroxene GroupADSi2O6
NaSodium
Naⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Naⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Naⓘ AnalcimeNa(AlSi2O6) · H2O
Naⓘ NephelineNa3K(Al4Si4O16)
Naⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
Naⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
MgMagnesium
Mgⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Mgⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
AlAluminium
Alⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Alⓘ AnalcimeNa(AlSi2O6) · H2O
Alⓘ NephelineNa3K(Al4Si4O16)
Alⓘ SanidineK(AlSi3O8)
Alⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
Alⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
SiSilicon
Siⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Siⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
Siⓘ AnalcimeNa(AlSi2O6) · H2O
Siⓘ NephelineNa3K(Al4Si4O16)
Siⓘ SanidineK(AlSi3O8)
Siⓘ Katophorite{Na}{CaNa}{Mg4Al}[(AlSi7)O22](OH)2
Siⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
Siⓘ Pyroxene GroupADSi2O6
KPotassium
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
Caⓘ Plagioclase(Na,Ca)[(Si,Al)AlSi2]O8
TiTitanium
Tiⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]
FeIron
Feⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Feⓘ AenigmatiteNa4[Fe102+Ti2]O4[Si12O36]

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

Williams, L. A. J. (1966). Geology of the Chanler’s Falls area. Geol. Surv. Kenya Rep., 75, 54.
Jennings, D. J. (1967). Geology of the Archer’s Post area. Rept. Geol. Surv. Kenya, (77).
Rix, P. (1967). Geology of the Kinna area. Rept. Geol. Surv. Kenya, 81.
Brotzu, P., Morbidelli, L., Piccirillo, E. M., & Traversa, G. (1983). The basanite to peralkaline phonolite suite of the plioquaternary Nyambeni multicentre volcanic range (East Kenya Plateau). Neues Jahrbuch für Mineralogie. Abhandlungen, 147(3), 253-280.
Brotzu, P., Morbidelli, L., Nicoletti, M., Piccirillo, E.M., Traversa, G. (1984) Miocene to quaternary volcanism in eastern Kenya: Sequence and geochronology. Tectonophysics, 101 (1) 75-86 doi:10.1016/0040-1951(84)90043-x
Dal Negro, A., Cundari, A., Piccirillo, E. M., Molin, G. M., & Uliana, D. (1986). Distinctive crystal chemistry and site configuration of the clinopyroxene from alkali basaltic rocks. Contributions to Mineralogy and Petrology, 92(1), 35-43. doi.org/10.1007/BF00373961
Hackman, B. D., Charsley, T. J., Kagasi, J., Key, R. M., Siambi, W. S., & Wilkinson, A. F. (1989). Geology of the Isiolo area. Rept. Geol. Surv. Kenya, (103), 88.
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.pp.116-118
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