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:
Margaritas No. 2 Mine, Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, Mexico

Oldest recorded age at locality: 53.8
Youngest recorded age at locality: 37.3

mindat Locality ID: 15673
mindat URL: http://www.mindat.org/loc-15673.html

Tectonic Settings:

Total number of sublocalities beneath "Margaritas No. 2 Mine, Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, Mexico": 0
Total number of bottom-level sublocalities: 0

Latitude: 0°0'0"N
Longitude: 0°0'0"E
Decimal Degree (lat, lon): 0,0

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: Cs H K O Si U V 

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

Structural Groups for minerals in this locality: 
FluoriteNoneSengierite

4 IMA Minerals at location:
Carnotite  (*)Margaritasite  (*)Uraninite  (*)Weeksite  (*)
Mineral nameStructural GroupsIMA FormulaMax Age (Ma)Min Age (Ma)# of Sublocalities containing mineralLOCALITY IDs, not mindat ids# of localities containing mineral
Carnotite  (*)NoneK2(UO2)2(VO4)2·3H2O44.9538.301184
Margaritasite  (*)SengieriteCs2(UO2)2(VO4)2·H2O44.9538.302
Uraninite  (*)FluoriteUO244.742.902718
Weeksite  (*)None(K)2(UO2)2(Si5O13)·4H2O44.9538.3042



Locality Notes from all Ages at Locality:
Age IDLocality Notes
Giersdorf_00000955The Sierra Peña Blanca is located to the north of Aldama City (Chihuahua State). It corresponds to an uplifted faulted block about 80 km long and 15 to 20 km wide, of Mesozoic and Cenozoic rocks, surrounded by basins to the west and the east. The average elevation of the sierra is 1,800 m, whereas the basins are around 1,600 m and decrease gradually eastward. This sierra,as well as other sierras belonging to the Basin and Range system, presents a general northward strike, with a tilt to the west.
Giersdorf_00000955bThe Sierra Peña Blanca is located to the north of Aldama City (Chihuahua State). It corresponds to an uplifted faulted block about 80 km long and 15 to 20 km wide, of Mesozoic and Cenozoic rocks, surrounded by basins to the west and the east. The average elevation of the sierra is 1,800 m, whereas the basins are around 1,600 m and decrease gradually eastward. This sierra,as well as other sierras belonging to the Basin and Range system, presents a general northward strike, with a tilt to the west.
Giersdorf_00000956The Sierra Peña Blanca is located to the north of Aldama City (Chihuahua State). It corresponds to an uplifted faulted block about 80 km long and 15 to 20 km wide, of Mesozoic and Cenozoic rocks, surrounded by basins to the west and the east. The average elevation of the sierra is 1,800 m, whereas the basins are around 1,600 m and decrease gradually eastward. This sierra,as well as other sierras belonging to the Basin and Range system, presents a general northward strike, with a tilt to the west.
Giersdorf_00000957The Sierra Peña Blanca is located to the north of Aldama City (Chihuahua State). It corresponds to an uplifted faulted block about 80 km long and 15 to 20 km wide, of Mesozoic and Cenozoic rocks, surrounded by basins to the west and the east. The average elevation of the sierra is 1,800 m, whereas the basins are around 1,600 m and decrease gradually eastward. This sierra,as well as other sierras belonging to the Basin and Range system, presents a general northward strike, with a tilt to the west.
Giersdorf_00000958The Sierra Peña Blanca is located to the north of Aldama City (Chihuahua State). It corresponds to an uplifted faulted block about 80 km long and 15 to 20 km wide, of Mesozoic and Cenozoic rocks, surrounded by basins to the west and the east. The average elevation of the sierra is 1,800 m, whereas the basins are around 1,600 m and decrease gradually eastward. This sierra,as well as other sierras belonging to the Basin and Range system, presents a general northward strike, with a tilt to the west.
Giersdorf_00000959The Sierra Peña Blanca is located to the north of Aldama City (Chihuahua State). It corresponds to an uplifted faulted block about 80 km long and 15 to 20 km wide, of Mesozoic and Cenozoic rocks, surrounded by basins to the west and the east. The average elevation of the sierra is 1,800 m, whereas the basins are around 1,600 m and decrease gradually eastward. This sierra,as well as other sierras belonging to the Basin and Range system, presents a general northward strike, with a tilt to the west.
Giersdorf_00000960The Nopal 1 Deposit is confined to a breccia zone or pipe, limited to by faults. The breccia pipe is 100m high x 20m x 40m wide. The deposit is found within the Nopal Rhyolite. Uranium minerals found in the deposit are primarily oxidized.
Giersdorf_00000961The Las Margaritas Deposit is hosedted by the Escuadra Formation and is found on the axis of a tectonic valley.
Giersdorf_00000962The Puerto 3 deposit is located to the northwest of the Las Margaritas deposit and is hosted by the Nopal Rhyolite overlain by the Escuadra Formation.


9 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_0000095553.853.853.8-42.2     Yes  17023Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPeña BlancaGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233The age of 53.8 is given for altered biotites and 42.2 is given for sanidine. This is the referred to in the literature as unit 1.
Giersdorf_00000955b4242      Yes  17023Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPeña BlancaGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233The age of 53.8 is given for altered biotites and 42.2 is given for sanidine. This is the referred to in the literature as unit 1.
Giersdorf_0000095644.742.943.8±0.9  sanidine  YesSanidine  17023Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPeña BlancaGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233Age given for the Nopal rhyolite which underlies what was previously referred to as the Escuadra Formation. The two are occasionally separated by a thin layer of pumice, but together make up what is referred to as unit 2 in the literature.
Giersdorf_0000095745.443.644.5±0.9  sanidine  YesSanidine  17023Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPeña BlancaGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233Age given for what was previously referred to as the Escuadra formation, which overlies the Nopal Rhyolite. The two are occasionally separated by a thin layer of pumice, but together make up what is referred to as unit 2 in the literature.
Giersdorf_0000095838.338.338.3 After approximately a 6 Ma hiatus, which is generalized in all of the surrounding areas, volcanic activity started again and formed the top part of the Escuadra Formation.sanidine  YesSanidine  17023Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPeña BlancaGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233Age given for the upper part of the Escuadra Formation, still a component of Unit 2.
Giersdorf_0000095937.337.337.3 The age of the Mesa Formation is given to be the youngest volcanogenic rock of the area.sanidine  YesSanidine  17023Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPeña BlancaGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233The Mesa formation is a component of what is referred to as Unit 5 of the locality.
Giersdorf_0000096144.9538.344.95-38.3     YesCarnotite, Margaritasite, Molybdenite, Phosphuranylite, Powellite, Tyuyamunite, Uranophane, ParauranophaneU15672Margaritas No. 1 Mine, Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoLas MargaritasGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233Age of the deposit is given by the window of ages for the Escuadra Formation.
Giersdorf_0000096044.742.943.8±0.9 The Nopal 1 Deposit and similar deposits are described as forming at the same time as the Nopal Rhyolite and are attributed its age.   YesUraniniteU17009Nopal No. 1 Mine, Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoNopal I mineGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233The Nopal 1 Deposit is used to describe the formation age of other similar deposits found in the Sierra Peña Blanca area, and are all found within the Nopal Rhyolite.
Giersdorf_0000096244.742.943.8±0.9     YesKaolinite, Montmorillonite, Uranophane, ParauranophaneU208595Puerto No. 3 Mine, Sierra Peña Blanca, Peña Blanca District, Aldama Municipality, Chihuahua, MexicoPuerto 3 mineGeorge-Aniel et al. (1991)10.2113/gsecongeo.86.2.233EG86_233The age is derived from the age of the host Nopal Rhyolite.


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