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:
Oklo Mine, Franceville, Haut-Ogooué Province, Gabon

Oldest recorded age at locality: 2200
Youngest recorded age at locality: 1720

mindat Locality ID: 1749
mindat URL: http://www.mindat.org/loc-1749.html

Tectonic Settings:

Total number of sublocalities beneath "Oklo Mine, Franceville, Haut-Ogooué Province, Gabon": 0
Total number of bottom-level sublocalities: 0

Latitude: 1°30'"S
Longitude: 13°16'0"E
Decimal Degree (lat, lon): -1.5,13.266666666667

AThis mineral is Anthropogenic.
GThis mineral is directly dated.
BThis mineral is reported as having this age.
YThis mineral is using an age reported as an element mineralization period.
OThis mineral is using an age calculated from all data at the locality.
RThe age displayed for this mineral originates from a different, non-child locality.
PThe 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.

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 Cu F Fe H K Mg Mo O P Pb S Si Ti U V Zn Zr 

Elements from minerals reported directly at this locality: Al Ba C Ca Cu F Fe H K Mg Mo O P Pb S Si Ti U V Zn Zr 

Structural Groups for minerals in this locality: 
ApatiteBaryteCalciteChalcopyriteChloriteClayCopperCorundumCovelliteDiaspore
DigeniteFluoriteFritzscheiteMicaMiniumMolybdeniteNolaniteNonePhosphuranylitePyrite
QuartzRocksaltScheeliteSchoepiteSphaleriteTitaniteWölsendorfiteZircon

43 IMA Minerals at location:
Baryte  (*)Bassetite  (*)Bornite  (*)Calcite  (*)Chalcopyrite  (*)
Chervetite  (*)Coffinite  (*)Copper  (*)Covellite  (*)Curienite  (*)
Dewindtite  (*)Digenite  (*)Duttonite  (*)Fluorapatite  (*)Fourmarierite  (*)
Francevillite  (*)Galena  (*)Goethite  (*)Hematite  (*)Ilmenite  (*)
Karelianite  (*)Kasolite  (*)Lead  (*)Metavanuralite  (*)Minium  (*)
Molybdenite  (*)Montroseite  (*)Muscovite  (*)Nolanite  (*)Pyrite  (*)
Quartz  (*)Roscoelite  (*)Rutherfordine  (*)Sphalerite  (*)Sudoite  (*)
Titanite  (*)Torbernite  (*)Uraninite  (*)Uranophane-α  (*)Vanuralite  (*)
Wölsendorfite  (*)Wulfenite  (*)Zircon  (*)
Mineral nameStructural GroupsIMA FormulaMax Age (Ma)Min Age (Ma)# of Sublocalities containing mineralLOCALITY IDs, not mindat ids# of localities containing mineral
Baryte  (*)BaryteBa(SO4)22001720011547
Bassetite  (*)NoneFe2+(UO2)2(PO4)2(H2O)1018401720051
Bornite  (*)NoneCu5FeS42200172005516
Calcite  (*)CalciteCa(CO3)22001720027770
Chalcopyrite  (*)ChalcopyriteCuFeS222001720027198
Chervetite  (*)NonePb2V5+2O72200172007
Coffinite  (*)ZirconU(SiO4)·nH2O220022000566
Copper  (*)CopperCu2200172003846
Covellite  (*)CovelliteCuS2200172004165
Curienite  (*)FritzscheitePb(UO2)2(VO4)2·5H2O18401720015
Dewindtite  (*)PhosphuranyliteH2Pb3(UO2)6O4(PO4)4·12H2O18401720082
Digenite  (*)DigeniteCu1.8S2200172001027
Duttonite  (*)NoneV4+O(OH)22200172007
Fluorapatite  (*)ApatiteCa5(PO4)3F2200172002740
Fourmarierite  (*)SchoepitePb1-xO3-2x(UO2)4(OH)4+2x·4H2O18401720061
Francevillite  (*)FritzscheiteBa(UO2)2(VO4)2·5H2O18401720043
Galena  (*)RocksaltPbS22001720024243
Goethite  (*)DiasporeFeO(OH)2200172007437
Hematite  (*)CorundumFe2O322001720014640
Ilmenite  (*)CorundumFe2+Ti4+O32200172005433
Karelianite  (*)CorundumV2O322001720017
Kasolite  (*)NonePb(UO2)(SiO4)·H2O184017200198
Lead  (*)CopperPb220017200192
Metavanuralite  (*)NoneAl(UO2)2(VO4)2(OH)·8H2O1840172004
Minium  (*)MiniumPb2+2Pb4+O4220017200247
Molybdenite  (*)MolybdeniteMoS22200172005800
Montroseite  (*)Diaspore(V3+,Fe2+,V4+)O(OH)220017200136
Muscovite  (*)Mica ClayKAl2(Si3Al)O10(OH)222001720017380
Nolanite  (*)NolaniteV3+8Fe3+2O14(OH)222001720019
Pyrite  (*)PyriteFeS222001720039462
Quartz  (*)QuartzSiO222001720061156
Roscoelite  (*)MicaKV3+2(Si3Al)O10(OH)2220017200253
Rutherfordine  (*)None(UO2)(CO3)18401720058
Sphalerite  (*)SphaleriteZnS22001720021482
Sudoite  (*)Chlorite ClayMg2Al3(Si3Al)O10(OH)822001720051
Titanite  (*)TitaniteCaTi(SiO4)O2200172004899
Torbernite  (*)NoneCu(UO2)2(PO4)2·12H2O1840172001059
Uraninite  (*)FluoriteUO22200172002718
Uranophane-α  (*)NoneCa(UO2)2(SiO3OH)2·5H2O184017200890
Vanuralite  (*)NoneAl(UO2)2(VO4)2(OH)·8.5H2O1840172003
Wölsendorfite  (*)WölsendorfitePb7(UO2)14O19(OH)4·12H2O18401720043
Wulfenite  (*)ScheelitePbMoO42200172001655
Zircon  (*)ZirconZr(SiO4)2200172005251



Locality Notes from all Ages at Locality:
Age IDLocality Notes
Giersdorf_00000792The Oklo uranium deposit is found in the Franceville sediment. It is host to the only known natural nuclear fission reactor, spread across over a dozen mineral nodes in the shale of the Franceville sediment.


2 Ages assigned to this locality:

Excel IDMax Age (Ma)Min Age (Ma)Age as listed in referenceDating MethodAge InterpretPrioritized?Sample SourceSample NumRun NumAge from other LocalityDated MineralMinerals explicitely stated as having this ageAge applies to these ElementsMinDat Locality IDDated Locality (Max Age)Location as listed in referenceReferenceReference DOIReference IDAge Notes
Giersdorf_00000792184017201780±60U-PbIndirect arguments may, however, put limits on the reactor age: (1) If the age is older than 1.78 b.y., the reactor would have run before the formation of the Franceville series. If this is true, it is almost impossible to explain the fact that the Oklo o    UraniniteU1749Oklo Mine, Franceville, Haut-Ogooué Province, GabonOklo MineLancelot et al. (1975)10.1016/0012-821X(75)90195-8EPSL25_189The sampled uranium minerals were drawn from zones outside of the reactor area in the Oklo deposit. Samples with too low a U concentration were additionally discarded. The age was compiled from many samples all intersecting on a concordia diagram, to the left or the right of the concordia line, and is also in agreement with the another author's Rb-Sr age for the Franceville sediment, as well as another's K-Ar age for a tuff in the Franceville deposit.
Giersdorf_00000821220022002200      Coffinite, Uraninite 1749Oklo Mine, Franceville, Haut-Ogooué Province, GabonOklo MinePearcy et al. (1994)10.1016/0883-2927(94)90030-2AG9_713Age is given in comparison to the Nopal deposit due to its similarity as a natural analogue to nuclear waste disposal systems


SampleSource LocalityReference URL


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