大兴安岭中南部宝日勿苏地区宝D1井早白垩世孢粉化石

通过对大兴安岭中南部宝日勿苏地区地质调查井宝D1井井深22~255.70m井段发现的孢粉化石的系统分析研究，共获得孢粉化石47属65种（包括未定种）.根据孢粉化石属种类型及其含量和变化特征，将孢粉化石组合划为Lycopodiacidites-Densoisporites-Piceaepollenites组合，时代为早白垩世早期，孢粉化石赋存地层相当于白音高老组.通过系统分析孢粉组合中主要孢粉属种及其母体植物的生长环境，推测大兴安岭中南部地区在早白垩世早期为暖温带-亚热带气候条件.同时旱生植物的大量出现，表明该区在早白垩世早期受到了干旱气候的影响，但与典型的干旱环境不同，推断与当时的火山活动有关.

EARLY CRETACEOUS SPOROPOLLEN ASSEMBLAGES FROM THE B-D1 WELL IN THE BOR US AREA OF CENTRAL-SOUTHERN DAXINGANLING MOUNTAINS

With systematic studies on the sporopollen fossils discovered from the section of 22-255.70 m of B-D1 well in Bor Us area, central-southern Daxinganling Mountains, 47 genera and 65 species (including undefined species) are obtained. According to their palynomorphs, contents and variation characteristics, the sporopollen fossils are assigned to the Lycopodiacidites-Densoisporites-Piceaepollenites assemblage with geological age of early stage of Early Cretaceous. The host stratum is corresponding to the Baiyingaolao Formation. Based on the analysis on the growing environment of major species and their parent plants, it is inferred that the central-southern Daxinganling Mountains were in warm temperate-subtropical climate conditions during the early stage of Early Cretaceous. In the meantime, the appearance of a large number of xerophytes indicates the influence of drought but different from typical arid environment, which is possibly related to volcanic activity at the time.