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:
Marshall Pass District, Saguache Co., Colorado, USA

Oldest recorded age at locality: 203
Youngest recorded age at locality: 94

mindat Locality ID: 134152
mindat URL: http://www.mindat.org/loc-134152.html

Tectonic Settings:

Total number of sublocalities beneath "Marshall Pass District, Saguache Co., Colorado, USA": 19
Total number of bottom-level sublocalities: 19

Number of Child Localities: 19
Child Localities:
Apache No. 4 Prospect
Big Indian Group
Bonita Claim
Erie No. 33 Prospect
Hidden Reserve Claim Group
Indian Creek Claims
Indian Creek Limonite Deposit (11; Claims: Indian Creek Placers 3-7)
Little Indian No. 6 Prospect
Lookout No. 22 Claim
Marshall Pass No. 5 Prospect
Marshall Pass Nos. 33 Claim (Marshall Pass Nos. 34 Claim; Marshall Pass Nos. 35 Claim; Marshall Pass Nos. 58 Claim; Olympia Extension; Marshall Pass Nos. 36 Claim)
Pinnacle Mine
Pitch Mine (Pitch Tunnel; Erie No. 28 Claim; Pinnacle Mine)
Uncompahgre No. 1
Unknown Gold (MRDS - 10118894)
Unknown Gold (MRDS - 10143303)
Unnamed Pegmatites
Unnamed Uranium - Feldspar Mine (MRDS - 10013132)
Vulcan Silver-Zinc Company Claims

Latitude: 38°22'52"N
Longitude: 106°17'21"W
Decimal Degree (lat, lon): 38.381111111111,-106.28916666667

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 As Ba C Ca Ce Cu Fe H K Mg Na Nb O P Pb S Sb Si Ta Th Ti U V Y Zn Zr 

Elements from minerals reported directly at this locality: H K O U 

Structural Groups for minerals in this locality: 
AutuniteBaryteChalcopyriteColumbiteCompreignaciteCorundumCovelliteFeldsparFluoriteFritzscheite
MarcasiteMeta-autuniteNonePhosphuranylitePyriteQuartzRocksaltRutileSchoepiteSphalerite
SpinelTetrahedriteZippeiteZircon

43 IMA Minerals at location:
Autunite  (*)Baryte  (*)Becquerelite  (*)Boltwoodite  (*)Bornite  (*)
Chalcocite  (*)Chalcopyrite  (*)Coffinite  (*)Compreignacite  (*)Covellite  (*)
Dolomite  (*)Euxenite-(Y)  (*)Fourmarierite  (*)Galena  (*)Hematite  (*)
Ianthinite  (*)Kasolite  (*)Liebigite  (*)Magnetite  (*)Marcasite  (*)
Meta-autunite  (*)Metatorbernite  (*)Metatyuyamunite  (*)Metazeunerite  (*)Microcline  (*)
Phosphuranylite  (*)Pyrite  (*)Quartz  (*)Rutile  (*)Sabugalite  (*)
Schoepite  (*)Sklodowskite  (*)Soddyite  (*)Sphalerite  (*)Tetrahedrite-(Zn)  (*)
Torbernite  (*)Uraninite  (*)Uranophane-α  (*)Xenotime-(Y)  (*)Yttrocolumbite-(Y)  (*)
Zeunerite  (*)Zippeite  (*)Zircon  (*)
Mineral nameStructural GroupsIMA FormulaMax Age (Ma)Min Age (Ma)# of Sublocalities containing mineralLOCALITY IDs, not mindat ids# of localities containing mineral
Autunite  (*)AutuniteCa(UO2)2(PO4)2·10-12H2O203943195962,195966,1959721272
Baryte  (*)BaryteBa(SO4)20394119596311547
Becquerelite  (*)NoneCa(UO2)6O4(OH)6·8H2O20394119596292
Boltwoodite  (*)None(K,Na)(UO2)(SiO3OH)·1.5H2O20394119596267
Bornite  (*)NoneCu5FeS42039411959665516
Chalcocite  (*)NoneCu2S203942195962,1959665707
Chalcopyrite  (*)ChalcopyriteCuFeS220394119596227198
Coffinite  (*)ZirconU(SiO4)·nH2O203941195966566
Compreignacite  (*)CompreignaciteK2(UO2)6O4(OH)6·7H2O20394027
Covellite  (*)CovelliteCuS203942195962,1959664165
Dolomite  (*)NoneCaMg(CO3)22039411959669895
Euxenite-(Y)  (*)ColumbiteY(NbTi)O6203941195970414
Fourmarierite  (*)SchoepitePb1-xO3-2x(UO2)4(OH)4+2x·4H2O203942195962,19596661
Galena  (*)RocksaltPbS203943195962,195963,19596624243
Hematite  (*)CorundumFe2O3203943195960,195962,19596614640
Ianthinite  (*)NoneU4+2(UO2)4O6(OH)4·9H2O203942195962,19596631
Kasolite  (*)NonePb(UO2)(SiO4)·H2O203942195962,195963198
Liebigite  (*)NoneCa2(UO2)(CO3)3·11H2O20394119596678
Magnetite  (*)SpinelFe2+Fe3+2O420394119597114899
Marcasite  (*)MarcasiteFeS2203942195962,1959665674
Meta-autunite  (*)Meta-autuniteCa(UO2)2(PO4)2·6H2O203942195962,195966388
Metatorbernite  (*)NoneCu(UO2)2(PO4)2·8H2O203941195966443
Metatyuyamunite  (*)FritzscheiteCa(UO2)2(VO4)2·3H2O203941195956129
Metazeunerite  (*)NoneCu(UO2)2(AsO4)2·8H2O203941195962182
Microcline  (*)FeldsparK(AlSi3O8)2039411959714924
Phosphuranylite  (*)PhosphuranyliteKCa(H3O)3(UO2)7(PO4)4O4·8H2O203941195972182
Pyrite  (*)PyriteFeS2203943195954,195962,19596639462
Quartz  (*)QuartzSiO2203943195963,195966,19597161156
Rutile  (*)RutileTiO22039411959705614
Sabugalite  (*)NoneHAl(UO2)4(PO4)4·16H2O20394119596687
Schoepite  (*)Schoepite(UO2)4O(OH)6(H2O)620394119596294
Sklodowskite  (*)NoneMg(UO2)2(SiO3OH)2·6H2O20394119596356
Soddyite  (*)None(UO2)2(SiO4)(H2O)220394119596244
Sphalerite  (*)SphaleriteZnS20394119596221482
Tetrahedrite-(Zn)  (*)TetrahedriteCu6(Cu4Zn2)Sb4S132039411959625317
Torbernite  (*)NoneCu(UO2)2(PO4)2·12H2O2039411959661059
Uraninite  (*)FluoriteUO2203945195954,195962,195963,195964,1959662718
Uranophane-α  (*)NoneCa(UO2)2(SiO3OH)2·5H2O203946195961,195962,195963,195964,195966,195972890
Xenotime-(Y)  (*)ZirconY(PO4)203941195958939
Yttrocolumbite-(Y)  (*)Columbite(Y,U,Fe2+)(Nb,Ta)O42039411959583
Zeunerite  (*)AutuniteCu(UO2)2(AsO4)2·12H2O203941195962185
Zippeite  (*)ZippeiteK2[(UO2)4(SO4)2O2(OH)2](H2O)4203941195966175
Zircon  (*)ZirconZr(SiO4)2039411959585251



Locality Notes from all Ages at Locality:
Age IDLocality Notes
Giersdorf_00000794The Lookout claims are a set of 34 claims in Saguache Co., Colorado, in the Marshall Pass uranium district. The district is located about 12 miles southeast of Sargents and spans the Saguache and Gunnison counties. Two of the major ore bodies, including the Lookout 22 body in particular, were found in alluvium at an elevation of approximately 10,000 feet.
Giersdorf_00000795The Lookout claims are a set of 34 claims in Saguache Co., Colorado, in the Marshall Pass uranium district. The district is located about 12 miles southeast of Sargents and spans the Saguache and Gunnison counties. Two of the major ore bodies, including the Lookout 22 body in particular, were found in alluvium at an elevation of approximately 10,000 feet.
Giersdorf_00000796The Lookout claims are a set of 34 claims in Saguache Co., Colorado, in the Marshall Pass uranium district. The district is located about 12 miles southeast of Sargents and spans the Saguache and Gunnison counties. Two of the major ore bodies, including the Lookout 22 body in particular, were found in alluvium at an elevation of approximately 10,000 feet.


3 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_00000794949494202Pb-238UThe ages given are noted by the author to be insufficiently sourced as they are only derived from a single sample. The author expresses that more Marshall Pass uranium minerals should be dated to collect an average age for the set of deposits.uraninite   UraniniteAutunite, Boltwoodite, Chalcocite, Chalcopyrite, Covellite, Galena, Ianthinite, Marcasite, Metazeunerite, Pyrite, Schoepite, Soddyite, Sphalerite, Uraninite, ZeuneriteU30136Lookout No. 22 Claim, Marshall Pass District, Saguache Co., Colorado, USALookout No. 22 ClaimGross (1965) AM50_909Pb202-U238 age for a uraninite sample
Giersdorf_00000795999999207Pb-235UThe ages given are noted by the author to be insufficiently sourced as they are only derived from a single sample. The author expresses that more Marshall Pass uranium minerals should be dated to collect an average age for the set of deposits.uraninite   UraniniteAutunite, Boltwoodite, Chalcocite, Chalcopyrite, Covellite, Galena, Ianthinite, Marcasite, Metazeunerite, Pyrite, Schoepite, Soddyite, Sphalerite, Uraninite, ZeuneriteU30136Lookout No. 22 Claim, Marshall Pass District, Saguache Co., Colorado, USALookout No. 22 ClaimGross (1965) AM50_909Pb207-U235 age for a uraninite sample
Giersdorf_00000796203203203207Pb-206PbThe ages given are noted by the author to be insufficiently sourced as they are only derived from a single sample. The author expresses that more Marshall Pass uranium minerals should be dated to collect an average age for the set of deposits.uraninite   UraniniteAutunite, Boltwoodite, Chalcocite, Chalcopyrite, Covellite, Galena, Ianthinite, Marcasite, Metazeunerite, Pyrite, Schoepite, Soddyite, Sphalerite, Uraninite, ZeuneriteU30136Lookout No. 22 Claim, Marshall Pass District, Saguache Co., Colorado, USALookout No. 22 ClaimGross (1965) AM50_909Pb207-Pb206 age for a uraninite sample


SampleSource LocalityReference URL


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