The Oligo-Miocene Asmari Formation in SW Iran represents sedimentation on a carbonate platform. Thin-section analysis allowed distinguishing 26 microfacies, which can be grouped into twelve microfacies associations that represent four main depositional environments: open-marine, outer-ramp, middle-ramp and inner-ramp settings. The carbonates have undergone a complex diagenetic history, from penecontemporaneous shallow-marine consolidation to deep-burial diagenesis. The most important processes that affected the carbonates are dolomitization (in different stages), cementation (by anhydrite and calcite), dissolution (fabric-selective and fabric-destructive), fracturing, stylolitization and neomorphism. Minor diagenetic processes that modified the sediments are pyritization, silicification, glauconitization, micritization and bioturbation. Diagenetic processes such as dolomitization, dissolution and fracturing improved the reservoir quality, whereas cementation and compaction have reduced the reservoir quality of the Asmari Formation. Whole-rock oxygen and carbon isotope analyses of limestone samples show that the isotopic composition of the carbonates was hardly affected by diagenesis and that the carbonates remained roughly in isotopic equilibrium with the Paleogene seawater. Some samples have, however, been affected significantly by diagenesis during deep burial in a closed to semi-closed diagenetic system.

中文翻译：

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伊朗西南碳酸盐台地渐中新世 Asmari 组储层质量的沉积环境、地球化学和成岩控制

伊朗西南部的渐新世 Asmari 组代表了碳酸盐台地上的沉积。薄片分析允许区分 26 个微相，这些微相可以分为 12 个微相组合，代表四种主要的沉积环境：开放海洋、外斜坡、中斜坡和内斜坡设置。碳酸盐岩经历了复杂的成岩历史，从准同期浅海固结到深埋成岩。影响碳酸盐岩的最重要过程是白云石化（在不同阶段）、胶结（硬石膏和方解石）、溶解（织物选择性和织物破坏性）、压裂、柱石化和新形作用。改变沉积物的次要成岩过程是黄铁矿化、硅化、海绿石化、微晶化和生物扰动。白云石化、溶解和压裂等成岩过程改善了储层质量，而胶结作用和压实作用降低了 Asmari 组的储层质量。对石灰岩样品的全岩氧和碳同位素分析表明，碳酸盐的同位素组成几乎不受成岩作用的影响，碳酸盐与古近系海水大致保持同位素平衡。然而，一些样品在封闭到半封闭的成岩系统中深埋期间受到成岩作用的显着影响。对石灰岩样品的全岩氧和碳同位素分析表明，碳酸盐的同位素组成几乎不受成岩作用的影响，碳酸盐与古近系海水大致保持同位素平衡。然而，一些样品在封闭到半封闭的成岩系统中深埋期间受到成岩作用的显着影响。对石灰岩样品的全岩氧和碳同位素分析表明，碳酸盐的同位素组成几乎不受成岩作用的影响，碳酸盐与古近系海水大致保持同位素平衡。然而，一些样品在封闭到半封闭的成岩系统中深埋期间受到成岩作用的显着影响。