Cenozoic sediments form extensive outcrops in the Niger Delta Basin. Detailed palynostratigraphic study was undertaken across Paleogene sequences exposed in Bende–Umuahia Area in up-dip sectors of the Niger Delta Basin, southeastern Nigeria, to establish different palynomorphs assemblage zones, with their corresponding ages. Palynological analysis was carried out on 27 selected outcrop samples, using the conventional maceration technique for recovering acid-insoluble organic-walled microfossils from sediments. Three Cenozoic lithostratigraphic units, including Imo Formation, Ameki Formation, and Ogwashi Formation, are exposed in the study area. Lithologies are sandstone, carbonaceous shale, mudstone, limestone, and the lignite. A total of 65 species of sporomorphs and 51 dinoflagellate cysts were identified. The recovered spores and pollen grains were used to establish six informal palynomorph assemblage zones, labeled as zone A – zone F, based on the first and the last occurrences of two or more species. These palynomorph assemblage zones include: (1) zone A — middle Paleocene Scabratriporites simpliformis–Bombacidites annae zone; (2) zone B — late Paleocene Foveotricolporites crassiexinus–Mauritidiites crassiexinus zone; (3) zone C — early Eocene Striatopollis catatumbus–Momipites africanus zone; (4) zone D — middle Eocene Margocolporites umuahiaensis–Gemmastephanocolporites brevicolpites zone; (5) zone E — late Eocene Cicatricosisporites dorogensis–Perfotricolpites nigerianus zone; and, (6) zone F — Oligocene–early Miocene Verrucatosporites usmensis – Magnastriatites howardii zone. The erected palynozones were correlated and compared with existing biozones in subsurface, down-dip sectors of the Niger Delta Basin, with pantropical palynological zones in tropical areas of Africa, and with palynofloral provinces of northern South America. A comparison of palynozones studied in southeastern Nigeria with other international palynozones, in this study, will assist in establishing the correlation of sediments for these areas.

中文翻译：

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尼日利亚东南部尼日尔三角洲盆地 Bende-Umuahia 地区古近系地层孢粉组合生物分带

新生代沉积物在尼日尔三角洲盆地形成了广泛的露头。对尼日利亚东南部尼日尔三角洲盆地上倾部分 Bende-Umuahia 地区出露的古近系序列进行了详细的孢粉地层研究，以建立不同的孢粉形组合带及其相应的年龄。对 27 个选定的露头样品进行孢粉学分析，使用常规浸渍技术从沉积物中回收酸不溶性有机壁微化石。研究区出露3个新生代岩石地层单元，包括Imo组、Ameki组和Ogwashi组。岩性为砂岩、碳质页岩、泥岩、石灰岩和褐煤。共鉴定出 65 种孢子体和 51 个甲藻囊肿。回收的孢子和花粉粒用于建立六个非正式的孢粉组合区，标记为 A 区 - F 区，基于两个或更多物种的第一次和最后一次出现。这些孢粉形组合带包括： (1) A 区——中古新世 Scabratriporites simpliformis-Bombacidites annae 带；(2) B 区——晚古新世 Foveotricolporites crassiexinus-Mauritidiites crassiexinus 区；（3）C区——早始新世Striatopollis catatumbus-Momipites Africaus区；(4) D区——中始新世Margocolporites umuahiaensis-Gemmastephanocolporites brevicolpites区；(5) E区——晚始新世Cicatricosisporites dorogensis-Perfotricolpites nigerianus区；(6) F 区——渐新世-早中新世 Verrucatosporites usmensis - Magnatriatites howardii 区。将竖立的孢粉带与尼日尔三角洲盆地地下下倾部分的现有生物带、非洲热带地区的泛热带孢粉带以及南美洲北部的孢粉植物区进行了关联和比较。在本研究中，将在尼日利亚东南部研究的孢粉带与其他国际孢粉带进行比较，将有助于确定这些地区沉积物的相关性。