Saurieši Quarry, Stopiņi Parish, Ropaži Municipality, Vidzeme Region, Latviai

Regional Level Types
Saurieši Quarry	Quarry (Flooded)
Stopiņi Parish	Parish
Ropaži Municipality	Municipality
Vidzeme Region	Region
Latvia	Country

Saurieši Gypsum Quarry is a Late Devonian (Salaspils suite) gypsum deposit and it is located in the Stopiņi Parish in Saurieši village. This is the closest quarry to Riga, where can find Devonian rocks. Nowadays it's the largest gypsum deposit in all Baltic states.

Gypsum was mined in this area as early as the end of the 19th century.
In 1936, gypsum mining operations started here in industrial quantities for the local Schmidt cement factory needs.
In the first years after the Second World War (1945-1948), the deposit was explored by geologists from Leningrad. After the survey, gypsum stocks were calculated and regular inventory of the obtained rocks was started.
In 1961, the Saurieši building materials plant (later - "Knauf") started operating here, after which an additional exploration of the deposit was carried out in 1964 and 1991. The company produced gypsum flour and drywall for building.
In 2008, the quarry reserves ran out and the last part, where mining was carried out, was flooded. The company began to extract gypsum in another quarry (Salaspils quarry). Now Saurieši is a big flooded quarry, consisting of four parts.

The total thickness of the sediments of the Salaspils suite in the deposit reaches 23.5 m. It is divided into three layers: the lower and upper, which do not contain gypsum, and the middle, which contains gypsum. The lower layer consists of a complex of clayey and marly rocks. The upper part of the suite, which is mainly distributed in the southwest of the quarry, forms a clay with domerite interlayers and its thickness varies from 0.3 to 7.2 m. The middle part - the valid rocks and they consists of satin spar, brown layered gypsum, dolomitized gypsum, domerite and clay layers. The thickness of the productive layer is around 18.5 meters (but only 10 meters were used). The cover layer, which is up to 8 m thick, consists of Quaternary sediments (peat, sand, moraine clay sand) and Salaspils suite of clayey dolomite, clay or domerite (whose thickness varies from 0.6 to 1.6 m). The annual extraction of gypsum was about 100 thousand m³.

At one time, gypsum from some massive suite layers (layers 17 and 21) of the Saurieši quarry was also evaluated as a building-decorative material. In 1956, when cutting two stone monoliths up to 1 m³, 8.8 m² (36 %) of decorative gypsum tile was obtained from one cubic meter. This material has been used by several public institutions in St. Petersburg (school on Mayakovskaya Street, shop on Vasilyevsky Island, subway wall decoration in "Narva" station).

In the quarry, one can find small pyrite specimens (almost all of them were oxidized over time), gypsum pseudomorphs after halite crystals (halite itself isn't found here), different types of gypsum (salmon and white satin spar, brown layered gypsum, selenite, brown plane crystals which form "rosettes"). Pseudomorphs and cones of grey and light blue celestine (!) are also found.

Other Regions, Features and Areas containing this locality

References