Abstract The stratigraphy and paleoenvironment of the Lower-Middle Eocene Apollonia Formation exposed at the northeastern and southern parts of Darnah city, northeast Libya, was studied in detail by means of foraminifera, where rich benthic and planktonic foraminiferal assemblages were recorded. Fifty-seven planktonic foraminiferal species and subspecies belonging to nineteen genera and seven families were identified and seventy-five benthic species and subspecies belonging to thirty-five genera and twenty-three families. The stratigraphic distribution of the recorded fauna in three selected surface sections enabled us to subdivide the studied succession into six planktonic and two benthic zones covering a time interval ranging from the Early to Middle Eocene. The planktonic zones were arranged from base to top as follows: Morozovella edgari, Morozovella subbotinae, Morozovella aragonensis, Acarinina pentacamerata (Early Eocene), Acarinina bullborooki and Globigerinatheka subconglobata subconglobata (Middle Eocene). The benthic zones are represented by the Anomalinoides trinitatensis (Early Eocene) and Bulimina jacksonensis (Middle Eocene). The established zones were discussed and correlated with the international standard zones and with those from neighbouring North Africa and Middle East countries. The Lower/Middle Eocene (Ypresian/Lutetian) boundary was discussed based on the zonal boundaries. The statistical analysis of the identified foraminiferal assemblages for each sample as well as the lithologic characteristics of the Apollonia Formation indicated marine middle to outer neritic setting. The high ratio of the calcareous foraminiferal assemblages and the moderate epifaunal/infaunal ratio reflect deposition in an environment of high calcium carbonate, normal salinity and low to moderate oxygenation levels.

中文翻译：

---

利比亚东北部达尔纳地区下-中始新世序列的地层和古环境

摘要 利用有孔虫对利比亚东北部达尔纳市东北部和南部出露的中始新世中下始新世阿波罗尼亚组地层和古环境进行了详细研究，记录了丰富的底栖和浮游有孔虫组合。共鉴定出浮游有孔虫19属7科57种和亚种，底栖动物35属23科75种。在三个选定的地表剖面中记录的动物群的地层分布使我们能够将研究的序列细分为六个浮游生物区和两个底栖区，涵盖从始新世早期到中始新世的时间间隔。浮游带从底部到顶部排列如下：Morozovella edgari，Morozovella subbotinae、Morozovella aragonensis、Acarinina pentacamerata（早始新世）、Acarinina bullborooki 和 Globigerinatheka subconglobata subconglobata（中始新世）。底栖带以 Anomalinoides trinitatensis（早始新世）和 Bulimina jacksonensis（中始新世）为代表。已建立的区域与国际标准区域以及邻近的北非和中东国家进行了讨论和关联。基于纬向边界讨论了下/中始新世（Ypresian/Lutetian）边界。对每个样品已识别的有孔虫组合的统计分析以及 Apollonia 组的岩性特征表明海洋中到外浅海环境。