In Poland, chalk is the name traditionally given to two different mineral raw materials: lacustrine chalk (calcareous tufa) and proper chalk rock (still often called as ”writing chalk” in Polish literature). The raw materials differ in origin and chemical composition and use.
Lacustrine chalk, also known as „meadow limestone” or „lacustrine limestone”, is a calcareous sediment of the Quaternary age, associated mainly with post-lacustrine series formed in times of the Last Glaciation. It is used in agriculture as calcareous fertilizer. Accumulations of lacustrine chalk occur mainly in northern and north-western Poland, often at the base of deposits of peat and calcareous gyttja. Chalk deposits occurrence is presented on the map.
Chalk is a weakly coherent and porous limestone rock, mainly used in the manufacture of rubber, paper, chemicals, dyes and cement. Cretaceous limestones of the chalk type used in production of cement (Chełm deposit) are discussed in the section dealing with limestone and marl raw material of the cement industry. Chalk deposits found in north-eastern Poland are related to erratics of Cretaceous chalk embedded in Quaternary glacial sediments (for example, the Mielnik and Kornica deposits).
According to the Regulation of the Minster of the Environment there are the limit values of the parameters that defines the deposit:
- proper chalk (“writing chalk”) is being documented to the depth of 70 m, with maximum overburden of 15 m, maximum ratio of overburden to deposit thickness of 0.2 and minimum alkalinity (CaO) of 80 % (44,8 % CaCO3);
- lacustrine chalk is being documented with minimum deposit thickness of 1 m, maximum ratio of overburden to deposit thickness of 0.3 and minimum alkalinity (CaO) of 40 % (71,2 % CaCO3);
The table 1 given below shows resources and the current state of exploration and development of chalk.
Anticipated economic resources of chalk in 2014 amounted to 199.88 million tonnes and increased by 244 thousand tonnes (0.1 %) in comparison with the previous year.
There was not any new deposit documented in 2014.
There were 2 deposits crossed out of “The balance…”: Czarnoszyce and Różyny II (Pomorskie Voivodeship) which were partially depleted and abandoned. The proper documentations aiming to cross these deposits out of “The balance…” were prepared and approved.
There are also other deposits which are supposed to be completely depleted but there have not been appropriate documentations accepted for crossing them out of the publication – such decisions must be taken by adequate geological administration body. Such deposits are: Iłowo (Kujawsko-pomorskie Voivodeship), Kruklin II, Lutek, Lutek II, Upałty (Warmińsko-mazurskie Voivodeship) and Prostynia II (Zachodniopomorskie Voivodeship).
There were new documentation with recalculated resources approved for 3 deposits: Ględy 1 and Wenecja (Warmińsko-mazurskie Voivodeship) and Kalwy Cieśle (Wielkopolskie Voivodeship). The resources growth amounted to 396 thousand tonnes (64 thousand tonnes and 333 thousaned tonnes for Wenecja and Kalwy Cieśle deposits respectively).
In 2014, production of chalk decreased by 11.30 thousand tonnes (7.2 %) to the level of 145 thousand tonnes. The majority of the output constitutes writing chalk production which amounted to almost 127 thousand tonnes (87.4 %). It is being exploited from 7 deposits (6 in Mazowieckie Voivodeship and 1 in Podlaskie Voivodeship). The remaining part of the production is lacustrine chalk output – it amounted to 18 thousand tonnes (12.6 %). The writing chalk production slightly decreased (by 1.7 thousand tonnes – 1.3 %) while production of lacustrine chalk decreased significantly (by 9.6 thousand tonnes – 34.5 %).
Lucastrine chalk occurr as co-occurring raw material in brown coal deposit Bełchatów – pole Szczerców and is being temporarily exploited from this deposit (the resources of the chalk are not officially calculated). The output was not carried out in 2014.
Economic resources of chalk in 2014 documented for 7 deposits amounted to 4.44 million tonnes which accounts for 84.8 % of anticipated economic resources.
The figure given below shows changes in domestic resources and production of chalk in Poland in the years 1989-2014.
Prepared by: Wojciech Szczygielski