【摘要】 为厘定内蒙古海拉尔盆地克鲁伦凹陷砂岩型铀矿找矿目的层及其时代，文章采集了钻孔内深灰色泥岩样品，并进行了孢粉化石分析鉴定。结果显示，与第四系不整合接触的下伏地层（平均200 m以浅）孢粉以桫椤孢及纤细光面单缝孢发育为特色，孢粉组合以苔藓、蕨类植物孢子为主，占比为25.95%～88.64%，平均为54.82%；裸子植物花粉次之，占比为11.36%～74.05%，平均为45.18%；未见任何被子植物花粉。这与下白垩统伊敏组上、下段桫椤孢孢粉组合带较为相似。综合区域铀成矿地质条件认为，该套地层更可能划分为下白垩统伊敏组上段，沉积时期为温暖湿润的热带古气候环境，砂体透水性好，本身还原容量较高，是一套有利的找矿目的层。更多还原

【Abstract】 In order to accurately determine the prospecting target layer and age of sandstone-type uranium deposits in Kelulun sag, Hailaer Basin, Inner Mongolia, dark gray mudstone samples were collected from boreholes, and sporopollen fossils were analyzed and identified. The results showed that the sporopollen in the shallow strata was characterized by the development of Alsophila spinulosa and Monospore. The sporopollen assemblage was dominated by moss and fern spores, with a content of 25.95%-88.64% at the average of 54.82%. Gymnosperm pollen followed, with a content of 11.36%-74.05% at the average of 45.18%; no angiosperm pollen was found. This is similar to the spore-pollen assemblage zone of Lower Cretaceous Yimin Formation. Based on the geological conditions of regional uranium mineralization, it is considered that the shallow strata in the area should be divided into the upper part of Lower Cretaceous Yimin Formation. The shallow strata were formed in a warm and humid tropical paleoclimate environment, sand body in the strata has good permeability and high reduction capacity, which can be regarded as favorable prospecting targets.更多还原