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Las Eras, Segovia, Castile and Leon, Spaini
Regional Level Types
Las ErasLake
SegoviaProvince
Castile and LeonAutonomous Community
SpainCountry

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Latitude & Longitude (WGS84):
41° 12' 1'' North , 4° 34' 55'' West
Latitude & Longitude (decimal):
41.20028,-4.58222
GeoHash:
G#: ezkdrsr34
GRN:
N28W03
Type:
Lake
Köppen climate type:
Csb : Warm-summer Mediterranean climate
Nearest Settlements:
PlacePopulationDistance
Fuente de Santa Cruz159 (2012)4.6km
Santiuste de San Juan Bautista740 (2012)5.0km
Coca2,042 (2012)5.4km
Villeguillo137 (2012)5.9km
Bocigas128 (2012)8.9km
Mindat Locality ID:
423738
Long-form identifier:
mindat:1:2:423738:2
GUID (UUID V4):
0


Las Eras is an ephemeral lake, located in a closed-drainage area in the Duero Basin, Central Spain . Las Eras with a maximum area of 0.1 km2 is a groundwater-fed, shallow basin (less than 0.6 m deep), affected by seasonal changes in temperature and in rainfall. Commonly from June to October, which corresponds with periods of low precipitation, the lake bed dries up and Las Eras converts to a playa.

hyperalkaline playa-lake reached the highest pH value recorded, “up to 11.3”, high carbonate concentrations, with chloride dominant over sulfate. , the concentration of dissolved potassium is an order of magnitude higher in Las Eras than in Caballo Alba and Bodón Blanco.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


19 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:

ⓘ Calcite
Formula: CaCO3
ⓘ Calcite var. Mg-rich Calcite
Formula: (Ca,Mg)CO3
ⓘ Dolomite
Formula: CaMg(CO3)2
ⓘ Dypingite
Formula: Mg5(CO3)4(OH)2 · 5H2O
ⓘ Eitelite
Formula: Na2Mg(CO3)2
ⓘ 'Feldspar Group'
ⓘ Gypsum
Formula: CaSO4 · 2H2O
ⓘ Halite
Formula: NaCl
ⓘ Hexahydrite
Formula: MgSO4 · 6H2O
ⓘ Huntite
Formula: CaMg3(CO3)4
ⓘ Hydromagnesite
Formula: Mg5(CO3)4(OH)2 · 4H2O
ⓘ Kaolinite
Formula: Al2(Si2O5)(OH)4
ⓘ Magnesite
Formula: MgCO3
ⓘ 'Mica Group'
ⓘ Natron
Formula: Na2CO3 · 10H2O
ⓘ Nesquehonite
Formula: MgCO3 · 3H2O
ⓘ Palygorskite
Formula: ◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
ⓘ Quartz
Formula: SiO2
ⓘ Sepiolite
Formula: Mg4(Si6O15)(OH)2 · 6H2O
ⓘ Starkeyite
Formula: MgSO4 · 4H2O
ⓘ Thénardite
Formula: Na2SO4
ⓘ Trona
Formula: Na3H(CO3)2 · 2H2O

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 3 - Halides
ⓘHalite3.AA.20NaCl
Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
ⓘCalcite5.AB.05CaCO3
ⓘMagnesite5.AB.05MgCO3
ⓘCalcite
var. Mg-rich Calcite		5.AB.05(Ca,Mg)CO3
ⓘDolomite5.AB.10CaMg(CO3)2
ⓘHuntite5.AB.25CaMg3(CO3)4
ⓘEitelite5.AC.05Na2Mg(CO3)2
ⓘNesquehonite5.CA.05MgCO3 · 3H2O
ⓘNatron5.CB.10Na2CO3 · 10H2O
ⓘTrona5.CB.15Na3H(CO3)2 · 2H2O
ⓘDypingite5.DA.05Mg5(CO3)4(OH)2 · 5H2O
ⓘHydromagnesite5.DA.05Mg5(CO3)4(OH)2 · 4H2O
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘThénardite7.AD.25Na2SO4
ⓘStarkeyite7.CB.15MgSO4 · 4H2O
ⓘHexahydrite7.CB.25MgSO4 · 6H2O
ⓘGypsum7.CD.40CaSO4 · 2H2O
Group 9 - Silicates
ⓘKaolinite9.ED.05Al2(Si2O5)(OH)4
ⓘPalygorskite9.EE.20◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
ⓘSepiolite9.EE.25Mg4(Si6O15)(OH)2 · 6H2O
Unclassified
ⓘ'Feldspar Group'-
ⓘ'Mica Group'-

List of minerals for each chemical element

HHydrogen
Hⓘ DypingiteMg5(CO3)4(OH)2 · 5H2O
Hⓘ GypsumCaSO4 · 2H2O
Hⓘ HexahydriteMgSO4 · 6H2O
Hⓘ HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
Hⓘ KaoliniteAl2(Si2O5)(OH)4
Hⓘ NatronNa2CO3 · 10H2O
Hⓘ NesquehoniteMgCO3 · 3H2O
Hⓘ Palygorskite◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
Hⓘ SepioliteMg4(Si6O15)(OH)2 · 6H2O
Hⓘ StarkeyiteMgSO4 · 4H2O
Hⓘ TronaNa3H(CO3)2 · 2H2O
CCarbon
Cⓘ CalciteCaCO3
Cⓘ DolomiteCaMg(CO3)2
Cⓘ DypingiteMg5(CO3)4(OH)2 · 5H2O
Cⓘ EiteliteNa2Mg(CO3)2
Cⓘ HuntiteCaMg3(CO3)4
Cⓘ HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
Cⓘ MagnesiteMgCO3
Cⓘ NatronNa2CO3 · 10H2O
Cⓘ NesquehoniteMgCO3 · 3H2O
Cⓘ TronaNa3H(CO3)2 · 2H2O
Cⓘ Calcite var. Mg-rich Calcite(Ca,Mg)CO3
OOxygen
Oⓘ CalciteCaCO3
Oⓘ DolomiteCaMg(CO3)2
Oⓘ DypingiteMg5(CO3)4(OH)2 · 5H2O
Oⓘ EiteliteNa2Mg(CO3)2
Oⓘ GypsumCaSO4 · 2H2O
Oⓘ HexahydriteMgSO4 · 6H2O
Oⓘ HuntiteCaMg3(CO3)4
Oⓘ HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
Oⓘ KaoliniteAl2(Si2O5)(OH)4
Oⓘ MagnesiteMgCO3
Oⓘ NatronNa2CO3 · 10H2O
Oⓘ NesquehoniteMgCO3 · 3H2O
Oⓘ Palygorskite◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
Oⓘ QuartzSiO2
Oⓘ SepioliteMg4(Si6O15)(OH)2 · 6H2O
Oⓘ StarkeyiteMgSO4 · 4H2O
Oⓘ ThénarditeNa2SO4
Oⓘ TronaNa3H(CO3)2 · 2H2O
Oⓘ Calcite var. Mg-rich Calcite(Ca,Mg)CO3
NaSodium
Naⓘ EiteliteNa2Mg(CO3)2
Naⓘ HaliteNaCl
Naⓘ NatronNa2CO3 · 10H2O
Naⓘ ThénarditeNa2SO4
Naⓘ TronaNa3H(CO3)2 · 2H2O
MgMagnesium
Mgⓘ DolomiteCaMg(CO3)2
Mgⓘ DypingiteMg5(CO3)4(OH)2 · 5H2O
Mgⓘ EiteliteNa2Mg(CO3)2
Mgⓘ HexahydriteMgSO4 · 6H2O
Mgⓘ HuntiteCaMg3(CO3)4
Mgⓘ HydromagnesiteMg5(CO3)4(OH)2 · 4H2O
Mgⓘ MagnesiteMgCO3
Mgⓘ NesquehoniteMgCO3 · 3H2O
Mgⓘ Palygorskite◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
Mgⓘ SepioliteMg4(Si6O15)(OH)2 · 6H2O
Mgⓘ StarkeyiteMgSO4 · 4H2O
Mgⓘ Calcite var. Mg-rich Calcite(Ca,Mg)CO3
AlAluminium
Alⓘ KaoliniteAl2(Si2O5)(OH)4
Alⓘ Palygorskite◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
SiSilicon
Siⓘ KaoliniteAl2(Si2O5)(OH)4
Siⓘ Palygorskite◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2O
Siⓘ QuartzSiO2
Siⓘ SepioliteMg4(Si6O15)(OH)2 · 6H2O
SSulfur
Sⓘ GypsumCaSO4 · 2H2O
Sⓘ HexahydriteMgSO4 · 6H2O
Sⓘ StarkeyiteMgSO4 · 4H2O
Sⓘ ThénarditeNa2SO4
ClChlorine
Clⓘ HaliteNaCl
CaCalcium
Caⓘ CalciteCaCO3
Caⓘ DolomiteCaMg(CO3)2
Caⓘ GypsumCaSO4 · 2H2O
Caⓘ HuntiteCaMg3(CO3)4
Caⓘ Calcite var. Mg-rich Calcite(Ca,Mg)CO3

Other Regions, Features and Areas containing this locality

Eurasian PlateTectonic Plate
EuropeContinent
Iberian PeninsulaPeninsula

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

[1]Sanz-Montero, M. E., Cabestrero, Ó., & Sánchez-Román, M. (2019). Microbial Mg-rich carbonates in an extreme alkaline lake (Las Eras, Central Spain). Frontiers in microbiology, 10, 148.
[2]Buey, Pablo, Sanz-Montero, María Esther, Rodríguez-Aranda, Juan Pablo, Sánchez-Román, Mónica, Nieto, Fernando (2025) The Miocene Source-to-Sink Evolution of Fibrous Clay Minerals in Hyperalkaline Playa-Lakes, Duero Basin (Central Spain). Minerals, 15 (1). doi:10.3390/min15010050
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