dolomitization

/doh'leuh muy'teuh zay"sheuhn, -mi-, dol'euh-/, n. Geol.
the conversion of limestone into dolomite.
[1860-65; DOLOMITIZE + -ATION]

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      process by which limestone is altered into dolomite; when limestone comes into contact with magnesium-rich water, the mineral dolomite, calcium and magnesium carbonate, CaMg(CO3)2, replaces the calcite (calcium carbonate, CaCO3) in the rock, volume for volume. Dolomitization involves recrystallization on a large scale. The dolomite mineral grains often show distinct faces, are of more or less uniform size throughout, and are larger than the calcite crystals in the limestone. When the recrystallization is not complete, the dolomite crystals are scattered throughout a calcite matrix. Sometimes rocks are formed that show patches of dolomite mottling the limestone where the magnesium-rich waters are thought to have filtered through the rock; such mottling does not appear to be controlled by bedding structures, however, and thus may be a product of the unmixing (separation) from a crystalline mixture containing calcium and magnesium carbonates of magnesium carbonate, which then forms dolomite.

      In the process of dolomitization the dolomite crystals cut across original calcite grains, fossils, and oölites (spherical modules of calcite) and sometimes include quartz grains within their boundaries. Dolomites do not preserve the textures of the original limestone nor the fossils (fossil) therein. Sometimes the only evidence that the limestone was formed from grains of older rocks is scattered quartz grains. Fossils are uncommon in dolomites but sometimes remain as faint shadows outlining the original shape without showing internal detail or as molds with poor detail and filled with tiny dolomite crystals.

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Universalium. 2010.

Look at other dictionaries:

  • Dolomitization — is a process by which dolomite is formed when magnesium ions replace calcium ions in calcite. It is common for this alteration into dolomite to take place due to evaporation of water in the sabkha area.[1] Dolomitization involves substantial… …   Wikipedia

  • dolomitization — (Amer.) n. geochemical process of converting into dolomite, changing limestone into dolomite (also dolomitisation) …   English contemporary dictionary

  • dolomitization — dolomitizacija statusas T sritis chemija apibrėžtis Kalcio karbonato (aragonito arba kalcito) virtimas dolomitu. atitikmenys: angl. dolomitization rus. доломитизация …   Chemijos terminų aiškinamasis žodynas

  • dolomitization — noun Date: 1862 the process of converting into dolomite • dolomitize transitive verb …   New Collegiate Dictionary

  • dolomitization — noun The conversion of a limestone rock into dolomite by replacement of calcium by magnesium …   Wiktionary

  • dolomitization —    The process whereby limestone becomes dolomite by the substitution of magnesium carbonate for part of the original calcium carbonate [10] …   Lexicon of Cave and Karst Terminology

  • dolomitization — do·lo·mit·i·za·tion …   English syllables

  • dolomitization — ˌ ̷ ̷ ̷ ̷ˌmīd.ə̇ˈzāshən, məd. noun ( s) : the process of converting into dolomite * * * /doh leuh muy teuh zay sheuhn, mi , dol euh /, n. Geol. the conversion of limestone into dolomite. [1860 65; DOLOMITIZE + ATION] * * * dolˈomitīzātion or… …   Useful english dictionary

  • dolomitizations — dolomitization (Amer.) n. geochemical process of converting into dolomite, changing limestone into dolomite (also dolomitisation) …   English contemporary dictionary

  • dolomite — dolomitic /dol euh mit ik/, adj. /doh leuh muyt , dol euh /, n. 1. a very common mineral, calcium magnesium carbonate, CaMg(CO3)2, occurring in crystals and in masses. 2. a rock consisting essentially or largely of this mineral. [1785 95; < F,… …   Universalium

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