Mineral Evolution Database

Created and maintained by the Mineral Evolution Project in partnership with RRUFF and mindat.

Mineral locality data provided by mindat.org

The Mineral Evolution database is currently under development.

The goal of this page is to present localities at which the mineral is found, and estimates of the oldest possible geologic age of the minerals at these localities.

Locality Name:
Homa Bay County, Kenya

Oldest recorded age at locality: 38
Youngest recorded age at locality: 1.3

mindat Locality ID: 301367
mindat URL: http://www.mindat.org/loc-301367.html

Tectonic Settings:

Total number of sublocalities beneath "Homa Bay County, Kenya": 12
Total number of bottom-level sublocalities: 10

Number of Child Localities: 8
Child Localities:
Buru Carbonatite
Homa Mountain Complex
Kuge Carbonatite
Mfangano Island
Rangwa Carbonatite Complex
Rangwa Complex
Ruri Complex
Sindo

Latitude: 0°-25'-45"N
Longitude: 34°23'52"E
Decimal Degree (lat, lon): -0.42916666666667,34.397777777778

A	This mineral is Anthropogenic.
G	This mineral is directly dated.
B	This mineral is reported as having this age.
Y	This mineral is using an age reported as an element mineralization period.
O	This mineral is using an age calculated from all data at the locality.
R	The age displayed for this mineral originates from a different, non-child locality.
P	The age displayed for this mineral is the range of ages for this mineral at all of this locality's children.
	This mineral's age has not yet been recorded.

Amphibole	Analcime	Apatite	Baryte	Calcite	Cancrinite	Clay	Corundum	Diaspore	Eudialyte
Feldspar	Fluorite	Garnet	Mica	None	Olivine	Perovskite	Pyroxene	Spinel	Titanite
Tridymite	Wollastonite

Aegirine ()*	Aegirine-augite ()*	Albite ()*	Analcime ()*	Andradite ()*
Arfvedsonite ()*	Baryte ()*	Calcite ()*	Cancrinite ()*	Diopside ()*
Eudialyte ()*	Eugsterite ()*	Fluorapatite ()*	Fluorite ()*	Forsterite ()*
Goethite ()*	Götzenite ()*	Hematite ()*	Hydroxylapatite ()*	Magnesio-arfvedsonite ()*
Magnetite ()*	Microcline ()*	Muscovite ()*	Nepheline ()*	Perovskite ()*
Phlogopite ()*	Richterite ()*	Siderite ()*	Titanite ()*	Wollastonite ()*

This Mineral list contains entries from this locality, including sub-localities. Minerals in bold are reported by mindat.org as occurring directly at this locality, and do not occur at any children (sublocalities) of this locality.

Elements at this locality, including sub-localities: Al Ba C Ca Cl F Fe H K Mg Na O P S Si Ti Zr

Elements from minerals reported directly at this locality:

Structural Groups for minerals in this locality:
Amphibole Analcime Apatite Baryte Calcite Cancrinite Clay Corundum Diaspore Eudialyte
Feldspar Fluorite Garnet Mica None Olivine Perovskite Pyroxene Spinel Titanite
Tridymite Wollastonite

30 IMA Minerals at location:

Mineral name	Structural Groups	IMA Formula	Max Age (Ma)	Min Age (Ma)	# of Sublocalities containing mineral	LOCALITY IDs, not mindat ids	# of localities containing mineral
Aegirine ()*	Pyroxene	NaFe³⁺Si₂O₆	38	1.3	7	77648,77649,77652,77655,77656,77657,77658	1022
Aegirine-augite ()*	Pyroxene	(Ca,Na)(Fe³⁺,Mg,Fe²⁺)Si₂O₆	11	4.1	1	77657	286
Albite ()*	Feldspar	Na(AlSi₃O₈)	12	1.3	1	77649	8803
Analcime ()*	Analcime	Na(AlSi₂O₆)·H₂O	38	17.5	1	77652	1627
Andradite ()*	Garnet	Ca₃Fe³⁺₂(SiO₄)₃	12	1.3	1	77649	1534
Arfvedsonite ()*	Amphibole	NaNa₂(Fe²⁺₄Fe³⁺)Si₈O₂₂(OH)₂	11	4.1	1	77657	295
Baryte ()*	Baryte	Ba(SO₄)	19.9	1.3	3	77648,77649,77656	11547
Calcite ()*	Calcite	Ca(CO₃)	38	1.3	6	77648,77649,77650,77652,77656,77657	27770
Cancrinite ()*	Cancrinite	(Na,Ca, )₈(Al₆Si₆)O₂₄(CO₃,SO₄)₂·2H₂O	11	4.1	1	77656	232
Diopside ()*	Pyroxene	CaMgSi₂O₆	38	17.5	2	77652,77655	4135
Eudialyte ()*	Eudialyte	Na₁₅Ca₆Fe₃Zr₃Si(Si₂₅O₇₃)(O,OH,H₂O)₃(Cl,OH)₂	11	4.1	1	77656	182
Eugsterite ()*	None	Na₄Ca(SO₄)₃·2H₂O			1	77659	32
Fluorapatite ()*	Apatite	Ca₅(PO₄)₃F	38	17.5	2	77652,77654	2740
Fluorite ()*	Fluorite	CaF₂	19.9	4.1	2	77648,77656	9617
Forsterite ()*	Olivine	Mg₂(SiO₄)			1	77655	1188
Goethite ()*	Diaspore	FeO(OH)	19.9	5.5	1	77648	7437
Götzenite ()*	None	Ca₄NaCa₂Ti(Si₂O₇)₂(OF)F₂	11	4.1	1	77656	27
Hematite ()*	Corundum	Fe₂O₃	19.9	5.5	1	77648	14640
Hydroxylapatite ()*	Apatite	Ca₅(PO₄)₃OH	12	1.3	1	77649	367
Magnesio-arfvedsonite ()*	Amphibole	NaNa₂(Mg₄Fe³⁺)Si₈O₂₂(OH)₂	12	1.3	2	77649,77657	79
Magnetite ()*	Spinel	Fe²⁺Fe³⁺₂O₄	38	1.3	6	77648,77649,77652,77654,77655,77656	14899
Microcline ()*	Feldspar	K(AlSi₃O₈)	12	1.3	1	77649	4924
Muscovite ()*	Mica Clay	KAl₂(Si₃Al)O₁₀(OH)₂			1	77655	17380
Nepheline ()*	Tridymite	Na₃K(Al₄Si₄O₁₆)	38	1.3	4	77649,77652,77657,77658	884
Perovskite ()*	Perovskite	CaTiO₃			1	77655	495
Phlogopite ()*	Mica Clay	KMg₃(AlSi₃O₁₀)(OH)₂	38	17.5	2	77652,77655	2273
Richterite ()*	Amphibole	Na(NaCa)Mg₅Si₈O₂₂(OH)₂	12	1.3	1	77649	148
Siderite ()*	Calcite	Fe(CO₃)	19.9	5.5	2	77648,77650	6417
Titanite ()*	Titanite	CaTi(SiO₄)O	38	1.3	2	77649,77652	4899
Wollastonite ()*	Wollastonite	CaSiO₃	12	1.3	2	77649,77656	1247

Locality Notes from all Ages at Locality:

Age ID	Locality Notes
Jen_0000407	carbonatite complex
Jen_0000408	carbonatite complex with transitional alkali basalt composition
Jen_0000410	carbonatite complex
Jen_0000592	MAGMATIC STYLE: Cone sheets, dykes, veins and extrusive pyroclastic deposits including bedded tuffs. ASSOCIATED SILICATE ROCKS: Ijolite, phonolite, nephelinite, breccia and fenite.
Jen_0000593	MAGMATIC STYLE: Cone sheets, dykes, veins and extrusive pyroclastic deposits including bedded tuffs. ASSOCIATED SILICATE ROCKS: Ijolite, phonolite, nephelinite, breccia and fenite.
Jen_0000594	MAGMATIC STYLE: Adjacent, deeply eroded volcanic complexes with cone sheets, dykes and many irregular intrusions. Also extrusive and intrusive tuffs and agglomerates. ASSOCIATED SILICATE ROCKS: Nepheline syenite, phonolite and melanephelinite; ijolite blocks in agglomerates; fenite.
Jen_0000595	MAGMATIC STYLE: Adjacent, deeply eroded volcanic complexes with cone sheets, dykes and many irregular intrusions. Also extrusive and intrusive tuffs and agglomerates. ASSOCIATED SILICATE ROCKS: Nepheline syenite, phonolite and melanephelinite; ijolite blocks in agglomerates; fenite.
Jen_0000605	MAGMATIC STYLE: Tuff and agglomerate. ASSOCIATED SILICATE ROCKS: Lavas and tuffs of basanite, tephrite, trachyte, phonolite, nephelinite and melilitite.
Jen_0000606	MAGMATIC STYLE: Tuff and agglomerate. ASSOCIATED SILICATE ROCKS: Lavas and tuffs of basanite, tephrite, trachyte, phonolite, nephelinite and melilitite.
Jen_0000638	MAGMATIC STYLE: Central exposed complex within partially eroded volcano. ASSOCIATED SILICATE ROCKS: Pyroxenite, ijolite, nepheline syenite, phonolite, melilitolite and fenite; nephelinitic and melilitic lavas, tuffs and agglomerates.
Jen_0000639	MAGMATIC STYLE: Central exposed complex within partially eroded volcano. ASSOCIATED SILICATE ROCKS: Pyroxenite, ijolite, nepheline syenite, phonolite, melilitolite and fenite; nephelinitic and melilitic lavas, tuffs and agglomerates.

12 Ages assigned to this locality:

Excel ID	Max Age (Ma)	Min Age (Ma)	Age as listed in reference	Dating Method	Sample Source	Age from other Locality	MinDat Locality ID	Dated Locality (Max Age)	Location as listed in reference	Reference	Reference DOI	Reference ID
Jen_0000407	12	1.3	12-1.3	K-Ar			209290	Homa Mountain Complex, Homa Bay County, Kenya	Homa Mountain Complex	Ernst and Bell (2010)	10.1007/s00710-009-0074-1	MP98_55
Jen_0000592	6.6	6.6	6.6	K-Ar	whole rock, biotite		209290	Homa Mountain Complex, Homa Bay County, Kenya	Homa Mountain	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
Jen_0000593	12	1.3	12-1.3	K-Ar	whole rock, biotite		209290	Homa Mountain Complex, Homa Bay County, Kenya	Homa Mountain	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
Jen_0000408	38	17.5	38-17.5	K-Ar			285421	Rangwa Carbonatite Complex, Homa Bay County, Kenya	Rangwa Complex	Ernst and Bell (2010)	10.1007/s00710-009-0074-1	MP98_55
Jen_0000638	28	28	28	K-Ar	pyroxene, biotite		285421	Rangwa Carbonatite Complex, Homa Bay County, Kenya	Kisingiri and Rangwa	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
Jen_0000639	38	17.5	38-17.5	K-Ar	pyroxene, biotite		285421	Rangwa Carbonatite Complex, Homa Bay County, Kenya	Kisingiri and Rangwa	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
Jen_0000410	11	4.1	11-4.1	K-Ar			227741	Ruri Complex, Homa Bay County, Kenya	North and South Ruri	Ernst and Bell (2010)	10.1007/s00710-009-0074-1	MP98_55
Jen_0000594	7.5	7.5	7.5	K-Ar	whole rock		227741	Ruri Complex, Homa Bay County, Kenya	North and South Ruri	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
Jen_0000595	11	4.1	11-4.1	K-Ar	whole rock		227741	Ruri Complex, Homa Bay County, Kenya	North and South Ruri	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
ree-00397	11	4.1	4.1-11 Ma				227741	Ruri Complex, Homa Bay County, Kenya	Ruri Complex	Orris and Grauch (2002)		USGSOFR02_189
Jen_0000605	12.6	12.6	12.6	K-Ar	whole rock, biotite	Yes	249667	Tinderet Volcano, Nandi County, Kenya	Tinderet and Londiani	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796
Jen_0000606	19.9	5.5	19.9-5.5	K-Ar	whole rock, biotite	Yes	249667	Tinderet Volcano, Nandi County, Kenya	Tinderet and Londiani	Woolley and Kjarsgaard (2008)	10.4095/225115	GSCOF5796

Sample	Source Locality	Reference URL

All locality data graciously provided by mindat.org

All age data...