Abstract: In order to trace back the resource of Mg²⁺, studying on a lot of examples of the dolostone origins, then finding that in geological environment, the Mg is mainly from diagenetic liquid, magmatite and other solid minerals, and Mg²⁺ organism. Mg²⁺ replaced Ca²⁺ of calcite under special hydrokinetics mechanism while dolomitization occurred. Based on the Mg²⁺ resource and hydrokinetic mechanism, the dolomitization models, accepted by most people, can be divided into evaporation model (Sabkha model), seepage-reflux model, mixing-water model, marine dolomitization model, deep burial model and hydrothermal model. Based on the different buried conditions, dolomitization can be grouped into three kinds: shallow dolomitization ( < 1000 m) , mid-deep dolomitization ( 1000-2000 m) and deep dolomitization ( > 2000 m).

Key words: dolostone, dolomitization, genesis model, hydrokinetics

摘要： 通过统计大量白云岩成因的例子, 追溯其离子来源, 得出: 地质环境中白云石化所需Mg²⁺主要来源于成岩流体、岩浆岩及其他固体矿物和生物, 这些Mg经特定的流体动力学机制交代方解石中的Ca²⁺使之转化为 白云石。根据Mg²⁺来源和流体动力学机制, 目前较成熟的白云石化成因模式主要有蒸发模式( 萨布哈模式)、渗透回流模式、混合水模式、海水模式、埋藏模式以及热液成因模式。根据不同的埋藏条件, 可将白云石化分为3 类: 浅层白云石化(<1000 m)、中深层白云石化( 1000 ～2000 m) 和深层白云石化(> 2000 m)。

关键词: 白云岩, 白云石化, 成因模式, 流体动力学