We logged five outcrops of the Middle Limestone Member (MLM) of the Early Eocene Rusayl Formation. The eastern sections contain more, much coarser and also more angular detritus than the western sections. Moreover, notable concentrations of red algae, gastropods, corals, oysters and echinoids only occur in the eastern sections. Benthic foraminifers are typical for the entire MLM, but in the west, they are more abundant (dominated by miliolids). Peloids are restricted to the western sections. While the western sections display a subtidal lagoonal facies, capped by thin intertidal deposits, the coarse clastic material of the eastern sections indicates the proximity of a mountainous paleocoast with a resulting rocky coast environment. The coarse eastern facies proves that the Saih Hatat Dome as part of the Oman Mountains had already emerged while the MLM accumulated. Because of the differences, no outcrop correlations between the western and eastern sections are possible. However, facies boundary correlations among the western sections are feasible, spanning a distance of 23.5 km. Among the eastern sections, basal coarse clastics as well as two bioclastic marker horizons were correlated over 26 km. Deposition of the MLM was favored by high temperatures during the Early Eocene Climatic Optimum (EECO) at 53-51 Ma and a correspondingly high eustatic sea-level. The presence of corals in proximity of a mountainous, rocky paleocoast indicates dry conditions (clear water) during the EECO. The final shallowing-up observed in the west is attributed to the end of the EECO when mean global temperatures and the eustatic sea-level dropped. Shallowing from subtidal to intertidal conditions restricted parts of the lagoon and caused evaporation/hypersaline conditions as indicated by monospecific small miliolids and also by early dolomitization due to Mg-rich brines (reflux model). The western sections show signs of dolomitization. The Al-Khod section is the first one to be reported to be intensely dolomitized.

我们记录了早始新世 Rusayl 地层中石灰岩段 (MLM) 的五个露头。与西部部分相比，东部部分包含更多、更粗糙且棱角分明的碎屑。此外，红藻、腹足动物、珊瑚、牡蛎和海胆类的显着浓度仅出现在东部地区。底栖有孔虫在整个传销中是典型的，但在西部，它们更为丰富（以粟类动物为主）。Peloids 仅限于西部地区。西部为潮下泻湖相，被薄薄的潮间带沉积物覆盖，东部部分的粗碎屑材料表明靠近多山的古海岸和由此产生的岩石海岸环境。粗糙的东部相证明作为阿曼山脉一部分的赛哈塔穹顶已经在传销积累时出现。由于存在差异，西部和东部剖面之间不可能存在露头相关性。然而，西段之间的相边界对比是可行的，跨越 23.5 公里的距离。在东部剖面中，基底粗碎屑和两个生物碎屑标记层相关联超过 26 公里。早始新世气候最适 (EECO) 期间 53-51 Ma 的高温和相应的高海平面有利于 MLM 的沉积。在多山、多岩石的古海岸附近存在珊瑚表明 EECO 期间条件干燥（清澈的水）。在西部观察到的最后一次变浅归因于 EECO 结束，当时全球平均气温和海平面下降。从潮下带到潮间带条件变浅限制了泻湖的部分并导致蒸发/高盐度条件，如单种小粟粒类和早期由富镁盐水引起的白云石化（回流模型）。西部有白云石化迹象。Al-Khod 部分是第一个据报道被强烈白云石化的部分。