黑龙江省柳树河盆地古近系八虎力组孢粉组合及其时代和古环境意义  

PALYNOLOGICAL ASSEMBLAGES FROM THE PALEOGENE BAHULI FORMATION IN THE LIUSHUHE BASIN,HEILONGJIANG PROVINCE,NE CHINA AND THEIR BEARING ON AGE AND PALAEOENVIRONMENT

作　　者：郑玉龙[1,2] 李振友[2] 王佰长[2] 季丰旭[2] 

机构地区：[1]中国地质大学(北京),北京100012 [2]大庆油田有限责任公司,大庆163453

出　　处：《微体古生物学报》2014年第2期164-174,共11页Acta Micropalaeontologica Sinica

基　　金：国家科技重大专项(2008ZX05055)资助~~

摘　　要：黑龙江省东部柳树河盆地古近系八虎力组为一套含油页岩矿床的地层。目前,对其时代的认定还没有确切的古生物学依据,尚存在不同的看法,同时,关于成矿环境的探讨也较薄弱。通过对该套地层开展系统的孢粉学研究,由下向上划分了4个孢粉组合,分别是Quercoidites-Retitricolpites-Retitricolporites组合、Retitricolpites-Retitricolporites组合、Polypodiaceaesporites-Retitricolpites-Retitricolporites组合和Pinuspollenites-Polypodiaceaesporites组合。根据孢粉组合特征,详细讨论了孢粉组合的地质时代,指出八虎力组时代为中始新世至晚始新世。根据孢粉组合的组成情况推测,八虎力组沉积时为亚热带-暖温带温暖湿润气候下的山间盆地环境。在山地高处生长有针、阔叶混交林植被,在低洼处生长有湿地水生植物、蕨类和苔藓类,从而有利于油页岩的形成和保存。温度向上可能有所降低,但幅度并不大。The Paleogene Bahuli Formation is a set of oil-shale-bearing sediments in the Liushuhe Basin, eastern Heilongjiang Province, NE China. At present, there is still no confident palaeontological evidence for its age assignment, remaining different views on this formation. Meanwhile, researches on the mineralization environment are also relatively poor. In this study, we conducted a systematic research of palynology on this formation. Four palynological assemblages are recognized from bottom to top including Quercoidites- Retitricolpites-Retitricolporites assemblage, Retitricolpites-Retitricolporites assemblage, Polypodiaceaesporites-Retitricolpites-Retitricolporites assemblage and Pinuspollenites- Polypodiaceaesporites assemblage. According to the characteristics of the palynological assemblages, the geologic ages of the assemblages are discussed in detail, pointing out that the Bahuli Formation is likely formed during the Middle to Late Eocene. In the light of composition of the palynologieal assemblages, the environment when the Bahuli Formation deposited is speculated as an intermontane basin where the climate is warm and hu- mid in subtropical to warm-temperate zone, which benefits the formation and preservation of oil shale. Needle and broad-leaved mixed forests grow in the surrounding mountains with wetland aquatic plants, mosses and ferns in lowlying lands. The temperature probably falled a little upwards as implied by the increasing of bisaccate pollen and the declining of Quercoidites, small retitricolpate and retitricolporate pollen as well, but the drop might not be great.

关 键 词：孢粉组合 古植被 古气候 八虎力组 中-晚始新世 柳树河盆地 黑龙江省 

分 类 号：Q914[天文地球—古生物学与地层学]