Selective dolomitization, where certain carbonate components are preferentially dolomitized over others, can be significant in the overall dynamic context of the global magnesium cycle. Thus, the abundance of these components can modify the Mg balance between the ocean and sediments, thereby disrupting the Mg cycle in certain geological times. Selective dolomitization may be connected to the apparent correlation between global dolomitization events in the Neogene and the synchronous rise in species abundance of coralline red algae (CRA), but the underlying issue remains unclear. In the Caribbean islands, excellent examples of Neogene partially dolomitized carbonates containing coralline red algal facies are described to understand selective dolomitization of different components (grains and matrix) by examining the well-preserved outcrop of partially dolomitized Mio–Pliocene carbonates at the Seru Grandi locality on Bonaire Island, in the Caribbean. The degree and timing of selective dolomitization of various carbonate components are assessed using petrographical and geochemical methods. The micrite matrix is dolomitized first, followed by coralline red algal bioclasts, and subsequently all other grains. Dolomite crystals appear to originate from within and immediately around coralline algal fragments, suggesting that dolomite could have initiated from internally sourced Mg of the CRA’s high-magnesium calcite skeleton. Collectively, these observations suggest that selective dolomitization is controlled primarily by reactive surface area of the carbonate components, but it is less clear as to whether there is a dependency on original mineralogy.

选择性白云石化（其中某些碳酸盐组分比其他组分优先白云石化）在全球镁循环的整体动态背景中可能具有重要意义。因此，这些成分的丰度可以改变海洋和沉积物之间的镁平衡，从而扰乱某些地质时期的镁循环。选择性白云石化可能与新近纪全球白云石化事件与珊瑚红藻（CRA）物种丰度同步上升之间的明显相关性有关，但根本问题仍不清楚。在加勒比群岛，通过检查 Seru Grandi 地区保存完好的部分白云石化 Mio-上新世碳酸盐岩露头，描述了含有珊瑚红藻相的新近纪部分白云石化碳酸盐的优秀例子，以了解不同成分（颗粒和基质）的选择性白云石化位于加勒比海的博内尔岛。使用岩石学和地球化学方法评估各种碳酸盐组分的选择性白云石化的程度和时间。微晶基质首先被白云石化，然后是珊瑚红藻生物碎屑，最后是所有其他颗粒。白云石晶体似乎起源于珊瑚藻碎片内部及其周围，这表明白云石可能源自 CRA 高镁方解石骨架的内部镁。总的来说，这些观察表明选择性白云石化主要受碳酸盐组分的反应表面积控制，但尚不清楚是否依赖于原始矿物学。