In the ancient rock record, early replacement of metastable marine calcium carbonate deposits by dolomite has long been associated with evidence of arid depositional environments. Such associations led to the development of the seepage reflux dolomitization model, whereby magnesium‐rich marine waters concentrated by evaporation descend into underlying sediments, replacing primary aragonite and calcite deposits with dolomite through rock–water interaction. In the modern arid coastal systems of Qatar, where marine waters concentrate to halite saturation, both aqueous geochemical measurements and mineralogical investigations show that replacement of calcium carbonate deposits by dolomite is not occurring to any consequential degree. At best dolomite formation is minor and localized. Instead, modern and mid‐Holocene coastal deposits retain their original mineralogy, showing little evidence of carbonate precipitation reactions with the notable exception of beachrock formation. Pleistocene coastal deposits are mostly absent in comparison with both Qatar Holocene coastal deposits, and Pleistocene coastal deposits from more humid settings. The lack of onshore Pleistocene‐aged carbonate outcrops in Qatar, as well as regionally, is interpreted to reflect coastal sediment denudation during emergence due to: (i) the absence of coastal marine lithification; and (ii) the absence of meteoric cementation and root stabilization in the highly‐arid realm. In contrast, marine Palaeogene and Miocene carbonate deposits are preserved in outcrop in Qatar, having suffered marine lithification by dolomite, thus promoting retention of carbonate strata through subsequent lowstands. These older deposits formed during times of ocean acidification, which, based on natural system and laboratory investigations, is interpreted to promote metastable carbonate dissolution and dolomite formation. The highly‐arid Holocene and Pleistocene coastal systems of Qatar represent limestone factories, but these deposits are not being retained to the rock record. Based on these observations, the association between the occurrence of dolomite and arid depositional settings may be to some degree a preservation bias.

中文翻译：

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卡塔尔的新生代沿海碳酸盐矿床：高干旱系统中白云岩保存偏差的证据

在古老的岩石记录中，长期以来用白云石替代亚稳的海相碳酸钙矿床一直与干旱的沉积环境有关。这种联系导致了渗流回流白云石化模型的发展，在该模型中，通过蒸发浓缩的富镁海水下降到下层沉积物中，通过岩水相互作用用白云石代替初级文石和方解石沉积物。在卡塔尔的现代干旱沿海系统中，海水集中到岩盐饱和度，含水地球化学测量和矿物学研究均表明，白云石不会替代碳酸钙沉积物。充其量，白云石的形成很少且局部。代替，现代和中全新世沿海沉积物保留了其原始的矿物学特征，除了滩石形成明显例外，几乎没有证据表明碳酸盐沉淀反应。与卡塔尔全新世沿海沉积物和潮湿环境中的更新世沿海沉积物相比，更新世沿海沉积物大多不存在。卡塔尔以及整个区域缺乏陆上更新世年龄的碳酸盐岩露头，这反映了出土过程中沿海沉积物的剥蚀，原因是：（ii）在高度干旱的领域中没有快速的胶结作用和根系稳定作用。相比之下，卡塔尔露头保存了海洋古近纪和中新世碳酸盐岩沉积物，白云岩曾使其海洋石化，因此，通过随后的低层发育促进碳酸盐岩地层的保留。这些较旧的沉积物是在海洋酸化期间形成的，根据自然系统和实验室研究，这些沉积物被解释为促进了亚稳态碳酸盐的溶解和白云石的形成。卡塔尔高度干旱的全新世和更新世沿海系统代表着石灰石工厂，但这些沉积物并未保留在岩石记录中。基于这些观察，白云石的发生与干旱沉积环境之间的关联在某种程度上可能是保存偏倚。卡塔尔高度干旱的全新世和更新世沿海系统代表着石灰石工厂，但这些沉积物并未保留在岩石记录中。基于这些观察，白云石的发生与干旱沉积环境之间的关联在某种程度上可能是保存偏倚。卡塔尔高度干旱的全新世和更新世沿海系统代表着石灰石工厂，但这些沉积物并未保留在岩石记录中。基于这些观察，白云石的发生与干旱沉积环境之间的关联在某种程度上可能是保存偏倚。