Lime­stones. Char­ac­ter­is­tics, vari­eties and dis­tri­b­u­tion

General Information

Lime­stone is a sed­i­men­ta­ry rock con­sist­ing main­ly of cal­ci­um car­bon­ate (cal­cite) or of the dou­ble car­bon­ate salt of cal­ci­um and mag­ne­sium (dolomite). Lime­stone is often com­posed of small fos­sils, shell frag­ments, and oth­er pet­ri­fied debris. Such fos­sils can often be seen with the naked eye dur­ing a detailed exam­i­na­tion of the sur­face of the rock, but some vari­eties of lime­stone have extreme­ly small grains that are hard­er to dis­cern.

Lime­stone is usu­al­ly gray in col­or, but it can also be white, yel­low, or brown. It is a soft rock sus­cep­ti­ble to mechan­i­cal dam­age. Lime­stone fizzes on con­tact with acids, releas­ing car­bon diox­ide.

Lime­stones vary great­ly in tex­ture and poros­i­ty, from shell lime­stone, which con­sists of loose­ly cement­ed shells of marine organ­isms, to micrit­ic lime­stones, struc­tures of which are so small they are invis­i­ble to the naked eye.

Chemical composition

Chem­i­cal com­po­si­tion of pure lime­stone is sim­i­lar to that of cal­cite, where CaO – 56% and CO2 – 44%. Lime­stone often con­tains the admix­ture of clay mate­r­i­al, dolomite and quartz, less often – gyp­sum, pyrite and organ­ic mate­r­i­al. Such admix­tures often deter­mine the name of a par­tic­u­lar lime­stone. Dolomitic lime­stones con­tain 4–17% MgO, marly lime­stones – 6–21% SiO2+R2O3. Sandy and siliceous lime­stones also con­tain quartz, opal and chal­cedony.

Characteristics

Phys­i­cal prop­er­ties of lime­stones can be very incon­sis­tent and depend on their struc­ture and tex­ture. Den­si­ty of pure lime­stone ranges from 2700 to 2750 kg/m3, while for argilla­ceous and dolomitic lime­stones den­si­ty is 2500 and 2900 kg/m3 respec­tive­ly.  Com­pres­sion resis­tance varies in the range of 10–100 MPa. Usu­al­ly, strength of lime­stones direct­ly cor­re­lates with their den­si­ty. Frost resis­tance of lime­stones varies great­ly depend­ing on their struc­ture. Crys­talline lime­stones are the most resis­tant to tem­per­a­ture changes and can sur­vive up to 300–400 freeze/thaw cycles. Accord­ing to their struc­ture, lime­stones are divid­ed into crys­talline, shelly, detri­tal, oolitic, clas­tic and mixed-struc­ture vari­eties.

Genesis of limestone

Lime­stones are most­ly of bio­log­i­cal or chem­i­cal ori­gin. Most lime­stones are formed in warm and shal­low marine waters, where nat­ur­al envi­ron­ment favors the exis­tence of marine organ­isms which form shells and skele­tons com­posed of cal­ci­um car­bon­ate. Afore­men­tioned shells and skele­tons accu­mu­late on the seafloor, and, under favor­able con­di­tions, under­go lithi­fi­ca­tion, which results in the for­ma­tion of lime­stone. Such lime­stones are organogenic, and the pres­ence of organ­ic admix­ture often points to their gen­e­sis. How­ev­er, evi­dence of bio­log­i­cal ori­gin is some­times lost due to dis­so­lu­tion or recrys­tal­liza­tion.

Some lime­stones are formed as a result of pre­cip­i­ta­tion of cal­ci­um car­bon­ate from sea or fresh water. Such lime­stones, there­fore, are of chem­i­cal ori­gin, and it is believed they are less com­mon than organogenic lime­stones. It is worth not­ing, how­ev­er, that cemen­ta­tion of organogenic lime­stones also occurs due to pre­cip­i­ta­tion of cal­ci­um car­bon­ate from water, but the key dif­fer­ence is that in this case organ­ic remains are the source of dis­solved cal­ci­um car­bon­ate.

Limestone uses

The field of appli­ca­tion of lime­stone includes:

• met­al­lur­gi­cal indus­try (flux mate­r­i­al);
• agri­cul­ture (soil lim­ing, min­er­al fer­til­iz­er);
• food indus­try (pro­duc­tion of sug­ar);

They are also used as a nat­ur­al build­ing mate­r­i­al from which arti­fi­cial stone is made, in hydraulic engi­neer­ing and road con­struc­tion, as rail­way bal­last etc. Var­i­ous frac­tions of crushed lime­stone are used in pro­duc­tion of cer­tain con­struc­tion parts based on bind­ing mate­ri­als. In addi­tion, it is used to pro­duce var­i­ous types of cement, asphalt and con­crete mix­tures.

Ukraine is one of the lead­ing pro­duc­ers of lime­stone in the world and exports sig­nif­i­cant vol­umes of this raw mate­r­i­al. Accord­ing to the State Sta­tis­tics Ser­vice of Ukraine, in 2021 the export of lime­stone from Ukraine amount­ed to 1.13 mil­lion tons, val­ued at 50.2 mil­lion US dol­lars. Although Ukraine is a sig­nif­i­cant pro­duc­er of lime­stone, spe­cif­ic types of lime­stone used in cer­tain indus­tries may be import­ed. In par­tic­u­lar, Ukraine imports lime­stone for the pro­duc­tion of cement, glass and ceram­ics. In 2020, 1.8 mil­lion tons of lime­stone-dolomite prod­ucts were import­ed to Ukraine, big­ger part of which was com­prised by lime­stone rub­ble of var­i­ous frac­tions. The biggest sup­pli­er was the Russ­ian Fed­er­a­tion – 68% as of 2021. In Jan­u­ary-June 2022, lime­stone imports decreased by 81% due to begin­ning of a full-scale Russ­ian inva­sion, and the share of the Russ­ian Fed­er­a­tion decreased to 29%. Half of the sup­plies were import­ed from Turkey, anoth­er 20% — from Moldo­va. As of Jan­u­ary-Feb­ru­ary 2023, deliv­er­ies of lime­stone and lime by rail amount­ed to 259 000 and 24 000 tons respec­tive­ly, which is 83 and 53% less than in 2022.

Availability of limestone in Ukraine

Lime­stone deposits are dis­trib­uted uneven­ly on the ter­ri­to­ry of Ukraine, depend­ing on the local geol­o­gy. Lime­stones are wide­spread in the Black Sea Depres­sion region, Crimea, Transnis­tria, the Carpathi­ans and Don­bas, where they are asso­ci­at­ed with Pale­o­zoic, Meso­zoic and Ceno­zoic sed­i­ments. On the ter­ri­to­ry of the Kher­son and Myko­laiv regions, shelly, oolitic and crys­talline lime­stones of the Neo­gene age (Sar­ma­t­ian, Meot­ic and Pon­tic) are wide­spread. They are being extract­ed in Var­varivsky, Tyligu­lo-Berezhan­sky, Snig­urivsky, Voz­ne­sen­sky and Novood­esky disc­tricts; the most promis­ing deposits are Bila Krynyt­sia, Sebynske and Kamyana Bal­ka. Remain­ing lime­stone reserves of the Hry­horiv deposit are 24152 thou­sand tons. Lime­stones of Pon­tic and Sar­ma­t­ian age are com­mon in Ode­sa region. Shell lime­stones form a lay­er 10–12 m thick here, the upper part of which is recrys­tal­lized and dense. The most famous deposits are Kry­va Bal­ka, Bul­dynske, Gulyai Bal­ka, Kovalske.

In the Dnipropetro­vsk region, lime­stones are dis­trib­uted in the north — with­in the Dnipro-Donets depres­sion and shield slopes, and in the south, near Kryvyi Rih. Lime­stone deposits here are of sig­nif­i­cant thick­ness (up to 70 m), but lie very deep (more than 100 m) and can­not be extract­ed by quar­ry­ing. In the south of the region typ­i­cal thick­ness of lime­stone deposits is 8–20 m, and it is extract­ed in quar­ries in the vicin­i­ty of the city of Nikopol, the vil­lage of Sholokhove, rail­way sta­tions Zhov­tokamyan­ka, Niko­lo-Kozel­sk and Litov­ka. The remain­ing reserves of lime­stone of the Zhov­tokamyanske deposit as of 01.01.2006 is 39470 thou­sand tons.

References

1. U.S. Gen­er­al Ser­vices Admin­is­tra­tion – Lime­stone: Char­ac­ter­is­tics, Uses And Prob­lem
2. Hobart M. King. Lime­stone. What is Lime­stone and How is it Used?
3. McLane, Michael, Sed­i­men­tol­ogy, Oxford Uni­ver­si­ty Press, 1995, p. 238 ISBN 0–19–507868–3
4. Гурський Д., Єсипчук К., Калінін В. та ін./ Металічні і неметалічні корисні копалини України. Том ІІ. Неметалічні корисні копалини. – Київ – Львів: Видавництво «Центр Європи», 2006. – 552 с.
5. Українська Асоціація Вапняної Промисловості. Дослідження імпортно-експортної динаміки вапняку, доломіту та мінерального порошку в Україні за І півріччя 2022 року.