The lower Miocene marine units of NW Iran (Hamedan–Miandoab area) were studied to establish a high-resolution biostratigraphy framework in the context of European standard biozonation (SBZ zonal scheme). The units are dominated by larger and small benthic foraminifera together with coralline algae and corals. Due to its position in the Tethyan Seaway between the Mediterranean and Indo-Pacific, the investigated area has high significance in palaeobiogeography. Seven species of benthic foraminifera were described, including Miogypsina globulina, Amphistegina bohdanowiczi, Elphidium crispum, Elphidium sp. 1, Borelis curdica, Austrotrillina asmariensis, and Peneroplis thomasi. The occurrence of Miogypsina globulina in the shallow-marine carbonates of the studied sections documents the Burdigalian SBZ 25 Zone. Austrotrillina asmariensis and Peneroplis thomasi occur with M. globulina. Simultaneously, their stratigraphical range is extended to the Burdigalian in the Middle East. Based on the discovery of lower Miocene deposits in the Hamedan–Miandoab area (previously mapped as Oligocene–Miocene units), the stratigraphy of northwest Central Iran is revised. The biostratigraphic results also present a more precise chronology for the marine transgression in the study area, initiating in the late early Miocene. The coralline algal assemblages and the abundance and diversity of larger benthic foraminifera indicate that shallow-marine Qom Formation got deposited in tropical to subtropical warm waters.

研究了伊朗西北部（Hamedan-Miandoab 地区）的下中新世海洋单元，以在欧洲标准生物分区（SBZ 分区方案）的背景下建立高分辨率生物地层框架。这些单位以大大小小的底栖有孔虫以及珊瑚藻和珊瑚为主。由于其位于地中海和印度-太平洋之间的特提斯海道，研究区域在古生物地理学中具有重要意义。描述了七种底栖有孔虫，包括Miogypsina globulina、Amphistegina bohdanowiczi、Elphidium crispum、Elphidium sp。1、Borelis curdica、Austrotrillina asmariensis和虾青虫。在所研究剖面的浅海相碳酸盐岩中出现的Miogypsina globulina记录了 Burdigalian SBZ 25 带。Austrotrillina asmariensis和Peneroplis thomasi与M一起出现。球蛋白. 同时，它们的地层范围延伸到中东的布尔地加利亚。根据在哈马丹-米安多阿布地区发现下中新世矿床（之前绘制为渐新世-中新世单元），对伊朗中部西北部的地层进行了修正。生物地层学结果也为研究区的海侵提供了更精确的年代学，始于中新世晚期。珊瑚藻组合和大型底栖有孔虫的丰度和多样性表明浅海库姆组沉积于热带至亚热带暖水区。