Sand and gravel

Two major groups of natural sand-gravel aggregates are differentiated: coarse aggregate group, comprising gravels and sand-gravel mix, and that of fine aggregates – comprising sands. Natural aggregates are used mainly in the building (concrete fill) and road construction (embankment and highway fill and road surfacing).

The demand for natural coarse aggregates is the largest, especially as distribution of their resources is far from uniform. The resources of natural coarse aggregates are generally small in central parts of the country, not covering the local demand.

The bulk of Polish natural aggregate deposits are of the Quaternary age. The share of deposits of the Pliocene, Miocene and Liassic age is subordinate.

The quality of raw material (especially its homogenity) depends largely on genetic type of a given deposit. Deposits of fluvial origin clearly predominate in the Carpathian-Sudetic zone (southern Poland). In the Sudety Mts, the most common deposits are those of sandy-gravel higher terraces of the Pleistocene age, built mainly of detritus of sandstones and crystalline rocks. In turn, in the Carpathian region the raw material basis mainly comprises gravel and sandy gravel deposits occurring on flood-plain terraces as well as valley side terraces rising above flood plains. The Carpathian deposits are characterized by predominance of material coming from disintegration of flysch rocks, except for those of the Dunajec River valley, showing fairly high contribution of crystalline rocks from the Tatry Mts.

In northern and central Poland (Polish Lowlands region), the most important deposits are of glacial (accumulation platform of front moraine) and fluvioglacial (outwash plain and esker) origin and resulting from river accumulation. Deposits from northern part of that area represent gravel-sandy accumulations mainly comprising Scandinavian material – debris of crystalline rocks and limestones with admixture of quartz and sandstones. In central and southern parts of this region, the deposits are mainly formed of sandy sediments with significant share of debris of local rocks.

According to the Regulation of the Minister of the Environment of the 22nd of December 2011 (number of Polish act: Dz. U. Nr 291, poz. 1712.), sand deposits should be charcterized by content of grains of silt fraction below 10 %, thickness not smaller than 2 m and the ratio of cover to deposit series not higher than 0.3 while sand and gravel deposits should be characterized by content of grains of silt fraction below 15 %, thickness not smaller than 2 m and the ratio of cover to deposit series not higher than 1.0.

Sand and gravel deposits occurence in Poland is presented on the map.

Table 1 shows resources and the current state of exploration and development of natural sand and gravel aggregates.

Table 1. Sand and gravel - millionn tonnes

Anticipated economic resources of natural aggregates totaled 18,360.90 million tonnes as of 31.12.2014. They increased by 388.40 million tonnes (2.1 %) in relation to the previous year.

Sand and gravel deposits are being documented within 4 subtypes: sand, sand and gravel, gravel, loamy sand. The resources of sands with sand content above 75 % amounted to 7,627.4 million tonnes from which 2,012.2 million tonnes are within exploited deposits; the resources of graveled-sands and sandy-gravel sands with sand content below 75 % amounted to 9,770.5 million tonnes (3,202.3 million tonnes within exploited deposits); the resources of gravel amounted to 937.5 million tonnes (286.9 million tonnes within exploited deposits); the resources of loamy sands amounted to 25.3 million tonnes (22.3 million tonnes within exploited deposits).

The resources increased due to:

• 467 new deposits documented in 2014 with anticipated economic resources amounted to 622.7 million tonnes. The largest resources were documented in Podlaskie Voivodeship (141.9 million tonnes within 34 new deposits), Wielkopolskie Voivodeship (74.2 million tonnes within 67 new deposits) and Dolnośląskie Voivodeship (60.8 million tonnes within 21 new deposits).
• the verifications of resources due to the changes of deposits boundaries and resources verifications, mainly in: Sępólno Wielkie deposit (resources increase equal 10.6 million tonnes), Sępólno Wielkie II (+5.8 million tonnes) and Ostrowąs (+5.6 million tonnes) in Zachodniopomorskie Voivodeship; Kazanice IV deposit (+4.2 million tonnes) in Warmińsko-Mazurskie Voivodeship; Brzeziny II (+6.3 million tonnes) in Świętokrzyskie Voivodeship; Bolimów III (+3.5 million tonnes) in Łódzkie Voivodeship; Brzeziny I (+3.3 million tonnes) in Lubelskie Voivodeship; Wola Batorska (+3.1 million tonnes) in Małopolskie Voivodeship.

The resources decreased by:

• the output (-146.5 million tonnes)
• crossing out 271 deposits from „The balance…” (-65.1 million tonnes)
• approving new documentations with reassessed resources (-23.8 million tonnes)

The table below shows changes within anticipated economic resources in particular voivodeships in 2014 (thousand tonnes).

The most deposits are located in Mazowieckie (1,241), Wielkopolskie (1,109), Lubelskie (877), Łódzkie (854) and Podkarpackie (756) Voivodeship.

Voivodeship with the biggest resources are: Dolnośląskie (2,292 million tonnes), Małopolskie (1,849 million tonnes), Podlaskie (1,411 million tonnes), Opolskie (1,404 million tonnes), Podkarpackie (1,277 million tonnes) and Mazowieckie (1,211 million tonnes).

Resources within deposits covered by detailed exploration (A, B, C₁) amounted to 10,437.8 million tonnes and accounts for 56.8 % of the total anticipated economic resources, with resources within deposits covered by preliminary exploration (C₂ and D) states for 43.2 %. Resources within exploited deposits amounted to 5,523.8 million tonnes (30.1 % of the total anticipated economic resources), resources within non-exploited deposits amounted to 11,546.6 million tonnes (62.9 %) while resources within abandoned deposits accounts for 7.0 % of total rerources (1,290.5 million tonnes).

In 2014, production of natural sands and gravel amounted to 146.5 million tonnes, decreasing by 26.7 million tonnes that is 15.4 % in relation to the previous year. The production decreased in 10 voivodeships. The table below shows changes within production in particular voivodeships in 2013 (thousand tonnes).

Figure below shows changes in domestic resources and production of sand and gravel in Poland in the years 1989 - 2014.

Natural sand and gravel are also obtained during the exploitation of Brown coal. In 2014 from Bełchatów deposit the output of sand and gravel amounted to 19.79 thousand tonnes.

Table 2. List of sand and gravel deposits - thousand tonnes

Prepared by: Wojciech Miśkiewicz, Dariusz Brzeziński, Janina Dyląg, Marzena Kozera, Joanna Stawierej, Agnieszka Wałkuska