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 homogeneity) 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 22^nd of December 2011 (number of Polish act: Dz. U. Nr 291, poz. 1712.), 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 17,735.14 million tonnes at the end of 2012. This means an increase by 502.6 million tonnes in relation to the previous year. That was mainly due to 645 new deposits documented in 2012 with anticipated economic resources amounted to 641.9 million tonnes. The largest resources were documented in Dolnośląskie Voivodeship (124.4 million tonnes within 37 new deposits), Łódzkie Voivodeship (101.6 million tonnes within 124 new deposits) and Pomorskie Voivodeship (78 million tonnes within 41 new deposits).

There were 222 deposits crossed out of “The balance…” with anticipated economic resources amounted to 41.2 million tonnes.

The table below shows changes within anticipated economic resources in particular voivodeships in 2012 (thousand tonens).

The most deposits are located in Mazowieckie (1,198), Wielkopolskie (1,031), Lubelskie (840), Łódzkie (804) and Podkarpackie (766) Voivodeship.

Resources within deposits covered by detailed exploration (A, B, C1) amounted to 9,735.38 million tonnes and accounts for 54.9 % of the total anticipated economic resources, with resources within deposits covered by preliminary exploration (C2) states for 45.1 %. Resources within exploited deposits amounted to 5,355.1 million tonnes (30.2 % of the total anticipated economic resources).

Economic resources amounted to 3,496.21 million tonnes and increased by 465.5 million tonnes in comparison with the previous year.

In 2012, production of natural sands and gravel amounted to 184.7 million tonnes, decreasing by 64 million tonnes that is 25.7 % in relation to the previous year. The production decreased in all of the 16 voivodeships. The table below shows changes within production in particular voivodeships in 2012 (thousand tonnes).

Figure below shows changes in domestic resources and production of sand and gravel in Poland in the years 1989 - 2012.

Natural sand and gravel are also obtained during the exploitation of Brown coal. In 2012 from Bełchatów deposit the output of sand and gravel amounted to 121 thousand tonnes.

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

Prepared by: Wojciech Miśkiewicz, Dariusz Brzeziński, Janina Dyląg, Alina Piotrowska