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Usaki Ijolite Complex, Homa Bay County, Kenyai
Regional Level Types
Usaki Ijolite ComplexVolcanic Complex
Homa Bay CountyCounty
KenyaCountry

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Latitude & Longitude (WGS84):
0° 31' South , 34° 24' East
Latitude & Longitude (decimal):
-0.51667,34.40000
GeoHash:
G#: kzbmnccq4
GRN:
S01E24
Type:
Volcanic Complex
Köppen climate type:
Am : Tropical monsoon climate
Mindat Locality ID:
406912
Long-form identifier:
mindat:1:2:406912:9
GUID (UUID V4):
0


Usaki ijolite complex lies immediately south of, and in contact with Nyamaji Volcanic Complex, Homa Bay County, Kenya and has max dimensions of 4 x 2 km, somewhat irregular in outline because it is partly obscured by recent deposits.

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:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ Andradite
Formula: Ca3Fe3+2(SiO4)3
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ Andradite var. Melanite
Formula: Ca3Fe3+2(SiO4)3
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ 'Apatite'
Formula: Ca5(PO4)3(Cl/F/OH)
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ 'Biotite'
Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ 'K Feldspar'
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ Nepheline
Formula: Na3K(Al4Si4O16)
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ Perovskite
Formula: CaTiO3
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ 'Pyroxene Group'
Formula: ADSi2O6
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ Titanite
Formula: CaTi(SiO4)O
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
ⓘ Wollastonite
Formula: Ca3(Si3O9)
References:
Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘPerovskite4.CC.30CaTiO3
Group 9 - Silicates
ⓘAndradite9.AD.25Ca3Fe3+2(SiO4)3
ⓘvar. Melanite9.AD.25Ca3Fe3+2(SiO4)3
ⓘTitanite9.AG.15CaTi(SiO4)O
ⓘAegirine-augite9.DA.20(NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6
ⓘWollastonite9.DG.05Ca3(Si3O9)
ⓘNepheline9.FA.05Na3K(Al4Si4O16)
Unclassified
ⓘ'Biotite'-K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
ⓘ'K Feldspar'-
ⓘ'Pyroxene Group'-ADSi2O6
ⓘ'Apatite'-Ca5(PO4)3(Cl/F/OH)

List of minerals for each chemical element

HHydrogen
Hⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Hⓘ ApatiteCa5(PO4)3(Cl/F/OH)
OOxygen
Oⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Oⓘ AndraditeCa3Fe23+(SiO4)3
Oⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Oⓘ NephelineNa3K(Al4Si4O16)
Oⓘ PerovskiteCaTiO3
Oⓘ TitaniteCaTi(SiO4)O
Oⓘ WollastoniteCa3(Si3O9)
Oⓘ Andradite var. MelaniteCa3Fe23+(SiO4)3
Oⓘ Pyroxene GroupADSi2O6
Oⓘ ApatiteCa5(PO4)3(Cl/F/OH)
FFluorine
Fⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Fⓘ ApatiteCa5(PO4)3(Cl/F/OH)
NaSodium
Naⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Naⓘ NephelineNa3K(Al4Si4O16)
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
AlAluminium
Alⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Alⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Alⓘ NephelineNa3K(Al4Si4O16)
SiSilicon
Siⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Siⓘ AndraditeCa3Fe23+(SiO4)3
Siⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Siⓘ NephelineNa3K(Al4Si4O16)
Siⓘ TitaniteCaTi(SiO4)O
Siⓘ WollastoniteCa3(Si3O9)
Siⓘ Andradite var. MelaniteCa3Fe23+(SiO4)3
Siⓘ Pyroxene GroupADSi2O6
PPhosphorus
Pⓘ ApatiteCa5(PO4)3(Cl/F/OH)
ClChlorine
Clⓘ ApatiteCa5(PO4)3(Cl/F/OH)
KPotassium
Kⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Kⓘ NephelineNa3K(Al4Si4O16)
CaCalcium
Caⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Caⓘ AndraditeCa3Fe23+(SiO4)3
Caⓘ PerovskiteCaTiO3
Caⓘ TitaniteCaTi(SiO4)O
Caⓘ WollastoniteCa3(Si3O9)
Caⓘ Andradite var. MelaniteCa3Fe23+(SiO4)3
Caⓘ ApatiteCa5(PO4)3(Cl/F/OH)
TiTitanium
Tiⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Tiⓘ PerovskiteCaTiO3
Tiⓘ TitaniteCaTi(SiO4)O
FeIron
Feⓘ Aegirine-augite(NaaCabFec2+Mgd)(Fee3+AlfFeg2+Mgh)Si2O6
Feⓘ AndraditeCa3Fe23+(SiO4)3
Feⓘ BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Feⓘ Andradite var. MelaniteCa3Fe23+(SiO4)3

Other Regions, Features and Areas containing this locality

AfricaContinent
African 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

Pulfrey, W. (1949) Ijolitic rocks near Homa Bay, western Kenya. Journal of the Geological Society, 105 (1) 425-459 doi:10.1144/gsl.jgs.1949.105.01-04.16
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
LE BAS, M. J., ASPDE, J., WOOLLEY, A. R. (1977) Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite. Journal of Petrology, 18 (2) 247-262 doi:10.1093/petrology/18.2.247
Bas, M. J., Aspden, J. A. (1981) The comparability of carbonatitic fluid inclusions in ijolites with natrocarbonatite lava. Bulletin Volcanologique, 44 (3). 429-438 doi:10.1007/bf02600574
Kalt, A., Hegner, E., Satir, M. (1997) Nd, Sr, and Pb isotopic evidence for diverse lithospheric mantle sources of East African Rift carbonatites. Tectonophysics, 278 (1) 31-45 doi:10.1016/s0040-1951(97)00093-0
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.121
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