Vote for your favorite mineral in #MinCup26! - Quartz vs. Asagiite
It's a classic vs a newbie as the most common named mineral in the crust Quartz is up against an exceedingly-rare sea foam-green mineral discovered just a few years ago Asagiite.
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Espadanal Mines, Rio Maior, Rio Maior, Santarém, Portugali
Regional Level Types
Espadanal MinesGroup of Mines (Inactive)
Rio MaiorCivil Parish
Rio MaiorMunicipality
SantarémDistrict
PortugalCountry

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Latitude & Longitude (WGS84):
39° 20' 32'' North , 8° 55' 50'' West
Latitude & Longitude (decimal):
Type:
Group of Mines (Inactive) - last checked 2026
Nearest Settlements:
PlacePopulationDistance
Rio Maior12,064 (2018)0.9km
Benedita8,556 (2012)9.8km
Alvorninha2,987 (2018)10.1km
A dos Francos1,701 (2018)10.3km
Vidais1,155 (2018)10.6km
Mindat Locality ID:
233190
Long-form identifier:
mindat:1:2:233190:7
GUID (UUID V4):
0
Name(s) in local language(s):
Campo Mineiro da Quinta da Várzea e do Espadanal, Rio Maior, Rio Maior, Distrito de Santarém, Portugal


Inactive coal (lignite) and diatomite mines – 1914/1915 to 1969.



The Rio Maior basin, formed during the Upper Pliocene, contains alternating layers of lignite and diatomite, separated by sands and clays, with a total thickness of approximately 110 meters. This sequence is overlain by 60 meters of clayey-sandy deposits and rests on sands, mainly kaolinite-bearing siliceous sands.
- Main mineralizations: lignite.
- Morphology: stratiform.
- Host rocks: sands, clays.
- Local geology: Upper Kimmeridgian sandstones containing plant and dinosaur remains; Vilafranca layers with lignite and diatomite deposits from Rio Maior.
-Regional geology: Undifferentiated Upper Jurassic; undifferentiated Plio-Pleistocene.
- Mining concessions: 1573, 1579, 1580, 1598, 1599, 792, 972
Source: Siorminp



A bacia de Rio Maior, formada no Pliocénico Superior, contem uma alternância de camadas de lignito e de diatomito, separadas por areias e argilas, com uma espessura da ordem dos 110 m; este conjunto está coberto por 60 m de formação argilo-arenosa e repousa sobre areias (sobretudo areias siliciosas cauliníferas).
- Mineralizações principais: lignito; morfologias: estratiforme; rochas encaixantes: areias, argilas.
- Geologia local: Grés Superiores do Kimmeridgiano com vegetais e dinossáurios. Camadas Vilafranquianas com lignitos e diatomitos de Rio Maior.
- Geologia regional: Jurássico Superior indiferenciado. Plio-plistocénico indiferenciado.
- Concessões: 1573, 1579, 1580, 1598, 1599, 792, 972
Fonte: Siorminp

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


1 valid mineral.

Rock Types Recorded


Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

'Jet'
Opal
Formula: SiO2 · nH2O
References:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
Opal4.DA.10SiO2 · nH2O
Unclassified
'Jet'-

List of minerals for each chemical element

HHydrogen
H OpalSiO2 · nH2O
OOxygen
O OpalSiO2 · nH2O
SiSilicon
Si OpalSiO2 · nH2O

Mindat Articles

Rio Maior Lignite and Diatomite Mines by Rui Nunes


Other Regions, Features and Areas containing this locality

Eurasian PlateTectonic Plate
EuropeContinent

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